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diff --git a/doc/manual/src/command-ref/command-ref.md b/doc/manual/src/command-ref/command-ref.md new file mode 100644 index 000000000..6a78075db --- /dev/null +++ b/doc/manual/src/command-ref/command-ref.md @@ -0,0 +1,2 @@ +This section lists commands and options that you can use when you work +with Nix. diff --git a/doc/manual/src/command-ref/conf-file-prefix.md b/doc/manual/src/command-ref/conf-file-prefix.md new file mode 100644 index 000000000..3140170ab --- /dev/null +++ b/doc/manual/src/command-ref/conf-file-prefix.md @@ -0,0 +1,51 @@ +# Name + +`nix.conf` - Nix configuration file + +# Description + +By default Nix reads settings from the following places: + + - The system-wide configuration file `sysconfdir/nix/nix.conf` (i.e. + `/etc/nix/nix.conf` on most systems), or `$NIX_CONF_DIR/nix.conf` if + `NIX_CONF_DIR` is set. Values loaded in this file are not forwarded + to the Nix daemon. The client assumes that the daemon has already + loaded them. + + - If `NIX_USER_CONF_FILES` is set, then each path separated by `:` + will be loaded in reverse order. + + Otherwise it will look for `nix/nix.conf` files in `XDG_CONFIG_DIRS` + and `XDG_CONFIG_HOME`. If these are unset, it will look in + `$HOME/.config/nix.conf`. + + - If `NIX_CONFIG` is set, its contents is treated as the contents of + a configuration file. + +The configuration files consist of `name = value` pairs, one per +line. Other files can be included with a line like `include path`, +where *path* is interpreted relative to the current conf file and a +missing file is an error unless `!include` is used instead. Comments +start with a `#` character. Here is an example configuration file: + + keep-outputs = true # Nice for developers + keep-derivations = true # Idem + +You can override settings on the command line using the `--option` +flag, e.g. `--option keep-outputs false`. Every configuration setting +also has a corresponding command line flag, e.g. `--max-jobs 16`; for +Boolean settings, there are two flags to enable or disable the setting +(e.g. `--keep-failed` and `--no-keep-failed`). + +A configuration setting usually overrides any previous value. However, +you can prefix the name of the setting by `extra-` to *append* to the +previous value. For instance, + + substituters = a b + extra-substituters = c d + +defines the `substituters` setting to be `a b c d`. This is also +available as a command line flag (e.g. `--extra-substituters`). + +The following settings are currently available: + diff --git a/doc/manual/src/command-ref/env-common.md b/doc/manual/src/command-ref/env-common.md new file mode 100644 index 000000000..6e2403461 --- /dev/null +++ b/doc/manual/src/command-ref/env-common.md @@ -0,0 +1,124 @@ +# Common Environment Variables + +Most Nix commands interpret the following environment variables: + + - `IN_NIX_SHELL`\ + Indicator that tells if the current environment was set up by + `nix-shell`. Since Nix 2.0 the values are `"pure"` and `"impure"` + + - `NIX_PATH`\ + A colon-separated list of directories used to look up Nix + expressions enclosed in angle brackets (i.e., `<path>`). For + instance, the value + + /home/eelco/Dev:/etc/nixos + + will cause Nix to look for paths relative to `/home/eelco/Dev` and + `/etc/nixos`, in this order. It is also possible to match paths + against a prefix. For example, the value + + nixpkgs=/home/eelco/Dev/nixpkgs-branch:/etc/nixos + + will cause Nix to search for `<nixpkgs/path>` in + `/home/eelco/Dev/nixpkgs-branch/path` and `/etc/nixos/nixpkgs/path`. + + If a path in the Nix search path starts with `http://` or + `https://`, it is interpreted as the URL of a tarball that will be + downloaded and unpacked to a temporary location. The tarball must + consist of a single top-level directory. For example, setting + `NIX_PATH` to + + nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz + + tells Nix to download and use the current contents of the + `master` branch in the `nixpkgs` repository. + + The URLs of the tarballs from the official nixos.org channels (see + [the manual for `nix-channel`](nix-channel.md)) can be abbreviated + as `channel:<channel-name>`. For instance, the following two + values of `NIX_PATH` are equivalent: + + nixpkgs=channel:nixos-21.05 + nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz + + The Nix search path can also be extended using the `-I` option to + many Nix commands, which takes precedence over `NIX_PATH`. + + - `NIX_IGNORE_SYMLINK_STORE`\ + Normally, the Nix store directory (typically `/nix/store`) is not + allowed to contain any symlink components. This is to prevent + “impure” builds. Builders sometimes “canonicalise” paths by + resolving all symlink components. Thus, builds on different machines + (with `/nix/store` resolving to different locations) could yield + different results. This is generally not a problem, except when + builds are deployed to machines where `/nix/store` resolves + differently. If you are sure that you’re not going to do that, you + can set `NIX_IGNORE_SYMLINK_STORE` to `1`. + + Note that if you’re symlinking the Nix store so that you can put it + on another file system than the root file system, on Linux you’re + better off using `bind` mount points, e.g., + + ```console + $ mkdir /nix + $ mount -o bind /mnt/otherdisk/nix /nix + ``` + + Consult the mount 8 manual page for details. + + - `NIX_STORE_DIR`\ + Overrides the location of the Nix store (default `prefix/store`). + + - `NIX_DATA_DIR`\ + Overrides the location of the Nix static data directory (default + `prefix/share`). + + - `NIX_LOG_DIR`\ + Overrides the location of the Nix log directory (default + `prefix/var/log/nix`). + + - `NIX_STATE_DIR`\ + Overrides the location of the Nix state directory (default + `prefix/var/nix`). + + - `NIX_CONF_DIR`\ + Overrides the location of the system Nix configuration directory + (default `prefix/etc/nix`). + + - `NIX_CONFIG`\ + Applies settings from Nix configuration from the environment. + The content is treated as if it was read from a Nix configuration file. + Settings are separated by the newline character. + + - `NIX_USER_CONF_FILES`\ + Overrides the location of the user Nix configuration files to load + from (defaults to the XDG spec locations). The variable is treated + as a list separated by the `:` token. + + - `TMPDIR`\ + Use the specified directory to store temporary files. In particular, + this includes temporary build directories; these can take up + substantial amounts of disk space. The default is `/tmp`. + + - `NIX_REMOTE`\ + This variable should be set to `daemon` if you want to use the Nix + daemon to execute Nix operations. This is necessary in [multi-user + Nix installations](../installation/multi-user.md). If the Nix + daemon's Unix socket is at some non-standard path, this variable + should be set to `unix://path/to/socket`. Otherwise, it should be + left unset. + + - `NIX_SHOW_STATS`\ + If set to `1`, Nix will print some evaluation statistics, such as + the number of values allocated. + + - `NIX_COUNT_CALLS`\ + If set to `1`, Nix will print how often functions were called during + Nix expression evaluation. This is useful for profiling your Nix + expressions. + + - `GC_INITIAL_HEAP_SIZE`\ + If Nix has been configured to use the Boehm garbage collector, this + variable sets the initial size of the heap in bytes. It defaults to + 384 MiB. Setting it to a low value reduces memory consumption, but + will increase runtime due to the overhead of garbage collection. diff --git a/doc/manual/src/command-ref/experimental-commands.md b/doc/manual/src/command-ref/experimental-commands.md new file mode 100644 index 000000000..cfa6f8b73 --- /dev/null +++ b/doc/manual/src/command-ref/experimental-commands.md @@ -0,0 +1,8 @@ +# Experimental Commands + +This section lists experimental commands. + +> **Warning** +> +> These commands may be removed in the future, or their syntax may +> change in incompatible ways. diff --git a/doc/manual/src/command-ref/files.md b/doc/manual/src/command-ref/files.md new file mode 100644 index 000000000..df5646c05 --- /dev/null +++ b/doc/manual/src/command-ref/files.md @@ -0,0 +1,4 @@ +# Files + +This section lists configuration files that you can use when you work +with Nix. diff --git a/doc/manual/src/command-ref/main-commands.md b/doc/manual/src/command-ref/main-commands.md new file mode 100644 index 000000000..e4f1f1d0e --- /dev/null +++ b/doc/manual/src/command-ref/main-commands.md @@ -0,0 +1,4 @@ +# Main Commands + +This section lists commands and options that you can use when you work +with Nix. diff --git a/doc/manual/src/command-ref/nix-build.md b/doc/manual/src/command-ref/nix-build.md new file mode 100644 index 000000000..43de7a6e6 --- /dev/null +++ b/doc/manual/src/command-ref/nix-build.md @@ -0,0 +1,111 @@ +# Name + +`nix-build` - build a Nix expression + +# Synopsis + +`nix-build` [*paths…*] + [`--arg` *name* *value*] + [`--argstr` *name* *value*] + [{`--attr` | `-A`} *attrPath*] + [`--no-out-link`] + [`--dry-run`] + [{`--out-link` | `-o`} *outlink*] + +# Description + +The `nix-build` command builds the derivations described by the Nix +expressions in *paths*. If the build succeeds, it places a symlink to +the result in the current directory. The symlink is called `result`. If +there are multiple Nix expressions, or the Nix expressions evaluate to +multiple derivations, multiple sequentially numbered symlinks are +created (`result`, `result-2`, and so on). + +If no *paths* are specified, then `nix-build` will use `default.nix` in +the current directory, if it exists. + +If an element of *paths* starts with `http://` or `https://`, it is +interpreted as the URL of a tarball that will be downloaded and unpacked +to a temporary location. The tarball must include a single top-level +directory containing at least a file named `default.nix`. + +`nix-build` is essentially a wrapper around +[`nix-instantiate`](nix-instantiate.md) (to translate a high-level Nix +expression to a low-level store derivation) and [`nix-store +--realise`](nix-store.md#operation---realise) (to build the store +derivation). + +> **Warning** +> +> The result of the build is automatically registered as a root of the +> Nix garbage collector. This root disappears automatically when the +> `result` symlink is deleted or renamed. So don’t rename the symlink. + +# Options + +All options not listed here are passed to `nix-store +--realise`, except for `--arg` and `--attr` / `-A` which are passed to +`nix-instantiate`. + + - `--no-out-link`\ + Do not create a symlink to the output path. Note that as a result + the output does not become a root of the garbage collector, and so + might be deleted by `nix-store + --gc`. + + - `--dry-run`\ + Show what store paths would be built or downloaded. + + - `--out-link` / `-o` *outlink*\ + Change the name of the symlink to the output path created from + `result` to *outlink*. + +The following common options are supported: + +# Examples + +```console +$ nix-build '<nixpkgs>' -A firefox +store derivation is /nix/store/qybprl8sz2lc...-firefox-1.5.0.7.drv +/nix/store/d18hyl92g30l...-firefox-1.5.0.7 + +$ ls -l result +lrwxrwxrwx ... result -> /nix/store/d18hyl92g30l...-firefox-1.5.0.7 + +$ ls ./result/bin/ +firefox firefox-config +``` + +If a derivation has multiple outputs, `nix-build` will build the default +(first) output. You can also build all outputs: + +```console +$ nix-build '<nixpkgs>' -A openssl.all +``` + +This will create a symlink for each output named `result-outputname`. +The suffix is omitted if the output name is `out`. So if `openssl` has +outputs `out`, `bin` and `man`, `nix-build` will create symlinks +`result`, `result-bin` and `result-man`. It’s also possible to build a +specific output: + +```console +$ nix-build '<nixpkgs>' -A openssl.man +``` + +This will create a symlink `result-man`. + +Build a Nix expression given on the command line: + +```console +$ nix-build -E 'with import <nixpkgs> { }; runCommand "foo" { } "echo bar > $out"' +$ cat ./result +bar +``` + +Build the GNU Hello package from the latest revision of the master +branch of Nixpkgs: + +```console +$ nix-build https://github.com/NixOS/nixpkgs/archive/master.tar.gz -A hello +``` diff --git a/doc/manual/src/command-ref/nix-channel.md b/doc/manual/src/command-ref/nix-channel.md new file mode 100644 index 000000000..24353525f --- /dev/null +++ b/doc/manual/src/command-ref/nix-channel.md @@ -0,0 +1,96 @@ +# Name + +`nix-channel` - manage Nix channels + +# Synopsis + +`nix-channel` {`--add` url [*name*] | `--remove` *name* | `--list` | `--update` [*names…*] | `--rollback` [*generation*] } + +# Description + +A Nix channel is a mechanism that allows you to automatically stay +up-to-date with a set of pre-built Nix expressions. A Nix channel is +just a URL that points to a place containing a set of Nix expressions. + +To see the list of official NixOS channels, visit +<https://nixos.org/channels>. + +This command has the following operations: + + - `--add` *url* \[*name*\]\ + Adds a channel named *name* with URL *url* to the list of subscribed + channels. If *name* is omitted, it defaults to the last component of + *url*, with the suffixes `-stable` or `-unstable` removed. + + - `--remove` *name*\ + Removes the channel named *name* from the list of subscribed + channels. + + - `--list`\ + Prints the names and URLs of all subscribed channels on standard + output. + + - `--update` \[*names*…\]\ + Downloads the Nix expressions of all subscribed channels (or only + those included in *names* if specified) and makes them the default + for `nix-env` operations (by symlinking them from the directory + `~/.nix-defexpr`). + + - `--rollback` \[*generation*\]\ + Reverts the previous call to `nix-channel + --update`. Optionally, you can specify a specific channel generation + number to restore. + +Note that `--add` does not automatically perform an update. + +The list of subscribed channels is stored in `~/.nix-channels`. + +# Examples + +To subscribe to the Nixpkgs channel and install the GNU Hello package: + +```console +$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable +$ nix-channel --update +$ nix-env -iA nixpkgs.hello +``` + +You can revert channel updates using `--rollback`: + +```console +$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version' +"14.04.527.0e935f1" + +$ nix-channel --rollback +switching from generation 483 to 482 + +$ nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version' +"14.04.526.dbadfad" +``` + +# Files + + - `/nix/var/nix/profiles/per-user/username/channels`\ + `nix-channel` uses a `nix-env` profile to keep track of previous + versions of the subscribed channels. Every time you run `nix-channel + --update`, a new channel generation (that is, a symlink to the + channel Nix expressions in the Nix store) is created. This enables + `nix-channel --rollback` to revert to previous versions. + + - `~/.nix-defexpr/channels`\ + This is a symlink to + `/nix/var/nix/profiles/per-user/username/channels`. It ensures that + `nix-env` can find your channels. In a multi-user installation, you + may also have `~/.nix-defexpr/channels_root`, which links to the + channels of the root user. + +# Channel format + +A channel URL should point to a directory containing the following +files: + + - `nixexprs.tar.xz`\ + A tarball containing Nix expressions and files referenced by them + (such as build scripts and patches). At the top level, the tarball + should contain a single directory. That directory must contain a + file `default.nix` that serves as the channel’s “entry point”. diff --git a/doc/manual/src/command-ref/nix-collect-garbage.md b/doc/manual/src/command-ref/nix-collect-garbage.md new file mode 100644 index 000000000..296165993 --- /dev/null +++ b/doc/manual/src/command-ref/nix-collect-garbage.md @@ -0,0 +1,30 @@ +# Name + +`nix-collect-garbage` - delete unreachable store paths + +# Synopsis + +`nix-collect-garbage` [`--delete-old`] [`-d`] [`--delete-older-than` *period*] [`--max-freed` *bytes*] [`--dry-run`] + +# Description + +The command `nix-collect-garbage` is mostly an alias of [`nix-store +--gc`](nix-store.md#operation---gc), that is, it deletes all +unreachable paths in the Nix store to clean up your system. However, +it provides two additional options: `-d` (`--delete-old`), which +deletes all old generations of all profiles in `/nix/var/nix/profiles` +by invoking `nix-env --delete-generations old` on all profiles (of +course, this makes rollbacks to previous configurations impossible); +and `--delete-older-than` *period*, where period is a value such as +`30d`, which deletes all generations older than the specified number +of days in all profiles in `/nix/var/nix/profiles` (except for the +generations that were active at that point in time). + +# Example + +To delete from the Nix store everything that is not used by the current +generations of each profile, do + +```console +$ nix-collect-garbage -d +``` diff --git a/doc/manual/src/command-ref/nix-copy-closure.md b/doc/manual/src/command-ref/nix-copy-closure.md new file mode 100644 index 000000000..7047d3012 --- /dev/null +++ b/doc/manual/src/command-ref/nix-copy-closure.md @@ -0,0 +1,85 @@ +# Name + +`nix-copy-closure` - copy a closure to or from a remote machine via SSH + +# Synopsis + +`nix-copy-closure` + [`--to` | `--from`] + [`--gzip`] + [`--include-outputs`] + [`--use-substitutes` | `-s`] + [`-v`] + _user@machine_ _paths_ + +# Description + +`nix-copy-closure` gives you an easy and efficient way to exchange +software between machines. Given one or more Nix store _paths_ on the +local machine, `nix-copy-closure` computes the closure of those paths +(i.e. all their dependencies in the Nix store), and copies all paths +in the closure to the remote machine via the `ssh` (Secure Shell) +command. With the `--from` option, the direction is reversed: the +closure of _paths_ on a remote machine is copied to the Nix store on +the local machine. + +This command is efficient because it only sends the store paths +that are missing on the target machine. + +Since `nix-copy-closure` calls `ssh`, you may be asked to type in the +appropriate password or passphrase. In fact, you may be asked _twice_ +because `nix-copy-closure` currently connects twice to the remote +machine, first to get the set of paths missing on the target machine, +and second to send the dump of those paths. If this bothers you, use +`ssh-agent`. + +# Options + + - `--to`\ + Copy the closure of _paths_ from the local Nix store to the Nix + store on _machine_. This is the default. + + - `--from`\ + Copy the closure of _paths_ from the Nix store on _machine_ to the + local Nix store. + + - `--gzip`\ + Enable compression of the SSH connection. + + - `--include-outputs`\ + Also copy the outputs of store derivations included in the closure. + + - `--use-substitutes` / `-s`\ + Attempt to download missing paths on the target machine using Nix’s + substitute mechanism. Any paths that cannot be substituted on the + target are still copied normally from the source. This is useful, + for instance, if the connection between the source and target + machine is slow, but the connection between the target machine and + `nixos.org` (the default binary cache server) is + fast. + + - `-v`\ + Show verbose output. + +# Environment variables + + - `NIX_SSHOPTS`\ + Additional options to be passed to `ssh` on the command + line. + +# Examples + +Copy Firefox with all its dependencies to a remote machine: + +```console +$ nix-copy-closure --to alice@itchy.labs $(type -tP firefox) +``` + +Copy Subversion from a remote machine and then install it into a user +environment: + +```console +$ nix-copy-closure --from alice@itchy.labs \ + /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4 +$ nix-env -i /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4 +``` diff --git a/doc/manual/src/command-ref/nix-daemon.md b/doc/manual/src/command-ref/nix-daemon.md new file mode 100644 index 000000000..e91cb01dd --- /dev/null +++ b/doc/manual/src/command-ref/nix-daemon.md @@ -0,0 +1,13 @@ +# Name + +`nix-daemon` - Nix multi-user support daemon + +# Synopsis + +`nix-daemon` + +# Description + +The Nix daemon is necessary in multi-user Nix installations. It performs +build actions and other operations on the Nix store on behalf of +unprivileged users. diff --git a/doc/manual/src/command-ref/nix-env.md b/doc/manual/src/command-ref/nix-env.md new file mode 100644 index 000000000..9138fa05a --- /dev/null +++ b/doc/manual/src/command-ref/nix-env.md @@ -0,0 +1,880 @@ +# Name + +`nix-env` - manipulate or query Nix user environments + +# Synopsis + +`nix-env` + [`--option` *name* *value*] + [`--arg` *name* *value*] + [`--argstr` *name* *value*] + [{`--file` | `-f`} *path*] + [{`--profile` | `-p`} *path(] + [`--system-filter` *system*] + [`--dry-run`] + *operation* [*options…*] [*arguments…*] + +# Description + +The command `nix-env` is used to manipulate Nix user environments. User +environments are sets of software packages available to a user at some +point in time. In other words, they are a synthesised view of the +programs available in the Nix store. There may be many user +environments: different users can have different environments, and +individual users can switch between different environments. + +`nix-env` takes exactly one *operation* flag which indicates the +subcommand to be performed. These are documented below. + +# Selectors + +Several commands, such as `nix-env -q` and `nix-env -i`, take a list of +arguments that specify the packages on which to operate. These are +extended regular expressions that must match the entire name of the +package. (For details on regular expressions, see regex7.) The match is +case-sensitive. The regular expression can optionally be followed by a +dash and a version number; if omitted, any version of the package will +match. Here are some examples: + + - `firefox`\ + Matches the package name `firefox` and any version. + + - `firefox-32.0`\ + Matches the package name `firefox` and version `32.0`. + + - `gtk\\+`\ + Matches the package name `gtk+`. The `+` character must be escaped + using a backslash to prevent it from being interpreted as a + quantifier, and the backslash must be escaped in turn with another + backslash to ensure that the shell passes it on. + + - `.\*`\ + Matches any package name. This is the default for most commands. + + - `'.*zip.*'`\ + Matches any package name containing the string `zip`. Note the dots: + `'*zip*'` does not work, because in a regular expression, the + character `*` is interpreted as a quantifier. + + - `'.*(firefox|chromium).*'`\ + Matches any package name containing the strings `firefox` or + `chromium`. + +# Common options + +This section lists the options that are common to all operations. These +options are allowed for every subcommand, though they may not always +have an effect. + + - `--file` / `-f` *path*\ + Specifies the Nix expression (designated below as the *active Nix + expression*) used by the `--install`, `--upgrade`, and `--query + --available` operations to obtain derivations. The default is + `~/.nix-defexpr`. + + If the argument starts with `http://` or `https://`, it is + interpreted as the URL of a tarball that will be downloaded and + unpacked to a temporary location. The tarball must include a single + top-level directory containing at least a file named `default.nix`. + + - `--profile` / `-p` *path*\ + Specifies the profile to be used by those operations that operate on + a profile (designated below as the *active profile*). A profile is a + sequence of user environments called *generations*, one of which is + the *current generation*. + + - `--dry-run`\ + For the `--install`, `--upgrade`, `--uninstall`, + `--switch-generation`, `--delete-generations` and `--rollback` + operations, this flag will cause `nix-env` to print what *would* be + done if this flag had not been specified, without actually doing it. + + `--dry-run` also prints out which paths will be + [substituted](../glossary.md) (i.e., downloaded) and which paths + will be built from source (because no substitute is available). + + - `--system-filter` *system*\ + By default, operations such as `--query + --available` show derivations matching any platform. This option + allows you to use derivations for the specified platform *system*. + +<!-- end list --> + +# Files + + - `~/.nix-defexpr`\ + The source for the default Nix expressions used by the + `--install`, `--upgrade`, and `--query --available` operations to + obtain derivations. The `--file` option may be used to override + this default. + + If `~/.nix-defexpr` is a file, it is loaded as a Nix expression. If + the expression is a set, it is used as the default Nix expression. + If the expression is a function, an empty set is passed as argument + and the return value is used as the default Nix expression. + + If `~/.nix-defexpr` is a directory containing a `default.nix` file, + that file is loaded as in the above paragraph. + + If `~/.nix-defexpr` is a directory without a `default.nix` file, + then its contents (both files and subdirectories) are loaded as Nix + expressions. The expressions are combined into a single set, each + expression under an attribute with the same name as the original + file or subdirectory. + + For example, if `~/.nix-defexpr` contains two files, `foo.nix` and + `bar.nix`, then the default Nix expression will essentially be + + ```nix + { + foo = import ~/.nix-defexpr/foo.nix; + bar = import ~/.nix-defexpr/bar.nix; + } + ``` + + The file `manifest.nix` is always ignored. Subdirectories without a + `default.nix` file are traversed recursively in search of more Nix + expressions, but the names of these intermediate directories are not + added to the attribute paths of the default Nix expression. + + The command `nix-channel` places symlinks to the downloaded Nix + expressions from each subscribed channel in this directory. + + - `~/.nix-profile`\ + A symbolic link to the user's current profile. By default, this + symlink points to `prefix/var/nix/profiles/default`. The `PATH` + environment variable should include `~/.nix-profile/bin` for the + user environment to be visible to the user. + +# Operation `--install` + +## Synopsis + +`nix-env` {`--install` | `-i`} *args…* + [{`--prebuilt-only` | `-b`}] + [{`--attr` | `-A`}] + [`--from-expression`] [`-E`] + [`--from-profile` *path*] + [`--preserve-installed` | `-P`] + [`--remove-all` | `-r`] + +## Description + +The install operation creates a new user environment, based on the +current generation of the active profile, to which a set of store paths +described by *args* is added. The arguments *args* map to store paths in +a number of possible ways: + + - By default, *args* is a set of derivation names denoting derivations + in the active Nix expression. These are realised, and the resulting + output paths are installed. Currently installed derivations with a + name equal to the name of a derivation being added are removed + unless the option `--preserve-installed` is specified. + + If there are multiple derivations matching a name in *args* that + have the same name (e.g., `gcc-3.3.6` and `gcc-4.1.1`), then the + derivation with the highest *priority* is used. A derivation can + define a priority by declaring the `meta.priority` attribute. This + attribute should be a number, with a higher value denoting a lower + priority. The default priority is `0`. + + If there are multiple matching derivations with the same priority, + then the derivation with the highest version will be installed. + + You can force the installation of multiple derivations with the same + name by being specific about the versions. For instance, `nix-env -i + gcc-3.3.6 gcc-4.1.1` will install both version of GCC (and will + probably cause a user environment conflict\!). + + - If `--attr` (`-A`) is specified, the arguments are *attribute + paths* that select attributes from the top-level Nix + expression. This is faster than using derivation names and + unambiguous. To find out the attribute paths of available + packages, use `nix-env -qaP`. + + - If `--from-profile` *path* is given, *args* is a set of names + denoting installed store paths in the profile *path*. This is an + easy way to copy user environment elements from one profile to + another. + + - If `--from-expression` is given, *args* are Nix + [functions](../expressions/language-constructs.md#functions) + that are called with the active Nix expression as their single + argument. The derivations returned by those function calls are + installed. This allows derivations to be specified in an + unambiguous way, which is necessary if there are multiple + derivations with the same name. + + - If *args* are store derivations, then these are + [realised](nix-store.md#operation---realise), and the resulting output paths + are installed. + + - If *args* are store paths that are not store derivations, then these + are [realised](nix-store.md#operation---realise) and installed. + + - By default all outputs are installed for each derivation. That can + be reduced by setting `meta.outputsToInstall`. + +## Flags + + - `--prebuilt-only` / `-b`\ + Use only derivations for which a substitute is registered, i.e., + there is a pre-built binary available that can be downloaded in lieu + of building the derivation. Thus, no packages will be built from + source. + + - `--preserve-installed`; `-P`\ + Do not remove derivations with a name matching one of the + derivations being installed. Usually, trying to have two versions of + the same package installed in the same generation of a profile will + lead to an error in building the generation, due to file name + clashes between the two versions. However, this is not the case for + all packages. + + - `--remove-all`; `-r`\ + Remove all previously installed packages first. This is equivalent + to running `nix-env -e '.*'` first, except that everything happens + in a single transaction. + +## Examples + +To install a specific version of `gcc` from the active Nix expression: + +```console +$ nix-env --install gcc-3.3.2 +installing `gcc-3.3.2' +uninstalling `gcc-3.1' +``` + +Note the previously installed version is removed, since +`--preserve-installed` was not specified. + +To install an arbitrary version: + +```console +$ nix-env --install gcc +installing `gcc-3.3.2' +``` + +To install using a specific attribute: + +```console +$ nix-env -i -A gcc40mips +$ nix-env -i -A xorg.xorgserver +``` + +To install all derivations in the Nix expression `foo.nix`: + +```console +$ nix-env -f ~/foo.nix -i '.*' +``` + +To copy the store path with symbolic name `gcc` from another profile: + +```console +$ nix-env -i --from-profile /nix/var/nix/profiles/foo gcc +``` + +To install a specific store derivation (typically created by +`nix-instantiate`): + +```console +$ nix-env -i /nix/store/fibjb1bfbpm5mrsxc4mh2d8n37sxh91i-gcc-3.4.3.drv +``` + +To install a specific output path: + +```console +$ nix-env -i /nix/store/y3cgx0xj1p4iv9x0pnnmdhr8iyg741vk-gcc-3.4.3 +``` + +To install from a Nix expression specified on the command-line: + +```console +$ nix-env -f ./foo.nix -i -E \ + 'f: (f {system = "i686-linux";}).subversionWithJava' +``` + +I.e., this evaluates to `(f: (f {system = +"i686-linux";}).subversionWithJava) (import ./foo.nix)`, thus selecting +the `subversionWithJava` attribute from the set returned by calling the +function defined in `./foo.nix`. + +A dry-run tells you which paths will be downloaded or built from source: + +```console +$ nix-env -f '<nixpkgs>' -iA hello --dry-run +(dry run; not doing anything) +installing ‘hello-2.10’ +this path will be fetched (0.04 MiB download, 0.19 MiB unpacked): + /nix/store/wkhdf9jinag5750mqlax6z2zbwhqb76n-hello-2.10 + ... +``` + +To install Firefox from the latest revision in the Nixpkgs/NixOS 14.12 +channel: + +```console +$ nix-env -f https://github.com/NixOS/nixpkgs/archive/nixos-14.12.tar.gz -iA firefox +``` + +# Operation `--upgrade` + +## Synopsis + +`nix-env` {`--upgrade` | `-u`} *args* + [`--lt` | `--leq` | `--eq` | `--always`] + [{`--prebuilt-only` | `-b`}] + [{`--attr` | `-A`}] + [`--from-expression`] [`-E`] + [`--from-profile` *path*] + [`--preserve-installed` | `-P`] + +## Description + +The upgrade operation creates a new user environment, based on the +current generation of the active profile, in which all store paths are +replaced for which there are newer versions in the set of paths +described by *args*. Paths for which there are no newer versions are +left untouched; this is not an error. It is also not an error if an +element of *args* matches no installed derivations. + +For a description of how *args* is mapped to a set of store paths, see +[`--install`](#operation---install). If *args* describes multiple +store paths with the same symbolic name, only the one with the highest +version is installed. + +## Flags + + - `--lt`\ + Only upgrade a derivation to newer versions. This is the default. + + - `--leq`\ + In addition to upgrading to newer versions, also “upgrade” to + derivations that have the same version. Version are not a unique + identification of a derivation, so there may be many derivations + that have the same version. This flag may be useful to force + “synchronisation” between the installed and available derivations. + + - `--eq`\ + *Only* “upgrade” to derivations that have the same version. This may + not seem very useful, but it actually is, e.g., when there is a new + release of Nixpkgs and you want to replace installed applications + with the same versions built against newer dependencies (to reduce + the number of dependencies floating around on your system). + + - `--always`\ + In addition to upgrading to newer versions, also “upgrade” to + derivations that have the same or a lower version. I.e., derivations + may actually be downgraded depending on what is available in the + active Nix expression. + +For the other flags, see `--install`. + +## Examples + +```console +$ nix-env --upgrade gcc +upgrading `gcc-3.3.1' to `gcc-3.4' +``` + +```console +$ nix-env -u gcc-3.3.2 --always (switch to a specific version) +upgrading `gcc-3.4' to `gcc-3.3.2' +``` + +```console +$ nix-env --upgrade pan +(no upgrades available, so nothing happens) +``` + +```console +$ nix-env -u (try to upgrade everything) +upgrading `hello-2.1.2' to `hello-2.1.3' +upgrading `mozilla-1.2' to `mozilla-1.4' +``` + +## Versions + +The upgrade operation determines whether a derivation `y` is an upgrade +of a derivation `x` by looking at their respective `name` attributes. +The names (e.g., `gcc-3.3.1` are split into two parts: the package name +(`gcc`), and the version (`3.3.1`). The version part starts after the +first dash not followed by a letter. `x` is considered an upgrade of `y` +if their package names match, and the version of `y` is higher that that +of `x`. + +The versions are compared by splitting them into contiguous components +of numbers and letters. E.g., `3.3.1pre5` is split into `[3, 3, 1, +"pre", 5]`. These lists are then compared lexicographically (from left +to right). Corresponding components `a` and `b` are compared as follows. +If they are both numbers, integer comparison is used. If `a` is an empty +string and `b` is a number, `a` is considered less than `b`. The special +string component `pre` (for *pre-release*) is considered to be less than +other components. String components are considered less than number +components. Otherwise, they are compared lexicographically (i.e., using +case-sensitive string comparison). + +This is illustrated by the following examples: + + 1.0 < 2.3 + 2.1 < 2.3 + 2.3 = 2.3 + 2.5 > 2.3 + 3.1 > 2.3 + 2.3.1 > 2.3 + 2.3.1 > 2.3a + 2.3pre1 < 2.3 + 2.3pre3 < 2.3pre12 + 2.3a < 2.3c + 2.3pre1 < 2.3c + 2.3pre1 < 2.3q + +# Operation `--uninstall` + +## Synopsis + +`nix-env` {`--uninstall` | `-e`} *drvnames…* + +## Description + +The uninstall operation creates a new user environment, based on the +current generation of the active profile, from which the store paths +designated by the symbolic names *drvnames* are removed. + +## Examples + +```console +$ nix-env --uninstall gcc +$ nix-env -e '.*' (remove everything) +``` + +# Operation `--set` + +## Synopsis + +`nix-env` `--set` *drvname* + +## Description + +The `--set` operation modifies the current generation of a profile so +that it contains exactly the specified derivation, and nothing else. + +## Examples + +The following updates a profile such that its current generation will +contain just Firefox: + +```console +$ nix-env -p /nix/var/nix/profiles/browser --set firefox +``` + +# Operation `--set-flag` + +## Synopsis + +`nix-env` `--set-flag` *name* *value* *drvnames* + +## Description + +The `--set-flag` operation allows meta attributes of installed packages +to be modified. There are several attributes that can be usefully +modified, because they affect the behaviour of `nix-env` or the user +environment build script: + + - `priority` can be changed to resolve filename clashes. The user + environment build script uses the `meta.priority` attribute of + derivations to resolve filename collisions between packages. Lower + priority values denote a higher priority. For instance, the GCC + wrapper package and the Binutils package in Nixpkgs both have a file + `bin/ld`, so previously if you tried to install both you would get a + collision. Now, on the other hand, the GCC wrapper declares a higher + priority than Binutils, so the former’s `bin/ld` is symlinked in the + user environment. + + - `keep` can be set to `true` to prevent the package from being + upgraded or replaced. This is useful if you want to hang on to an + older version of a package. + + - `active` can be set to `false` to “disable” the package. That is, no + symlinks will be generated to the files of the package, but it + remains part of the profile (so it won’t be garbage-collected). It + can be set back to `true` to re-enable the package. + +## Examples + +To prevent the currently installed Firefox from being upgraded: + +```console +$ nix-env --set-flag keep true firefox +``` + +After this, `nix-env -u` will ignore Firefox. + +To disable the currently installed Firefox, then install a new Firefox +while the old remains part of the profile: + +```console +$ nix-env -q +firefox-2.0.0.9 (the current one) + +$ nix-env --preserve-installed -i firefox-2.0.0.11 +installing `firefox-2.0.0.11' +building path(s) `/nix/store/myy0y59q3ig70dgq37jqwg1j0rsapzsl-user-environment' +collision between `/nix/store/...-firefox-2.0.0.11/bin/firefox' + and `/nix/store/...-firefox-2.0.0.9/bin/firefox'. +(i.e., can’t have two active at the same time) + +$ nix-env --set-flag active false firefox +setting flag on `firefox-2.0.0.9' + +$ nix-env --preserve-installed -i firefox-2.0.0.11 +installing `firefox-2.0.0.11' + +$ nix-env -q +firefox-2.0.0.11 (the enabled one) +firefox-2.0.0.9 (the disabled one) +``` + +To make files from `binutils` take precedence over files from `gcc`: + +```console +$ nix-env --set-flag priority 5 binutils +$ nix-env --set-flag priority 10 gcc +``` + +# Operation `--query` + +## Synopsis + +`nix-env` {`--query` | `-q`} *names…* + [`--installed` | `--available` | `-a`] + [{`--status` | `-s`}] + [{`--attr-path` | `-P`}] + [`--no-name`] + [{`--compare-versions` | `-c`}] + [`--system`] + [`--drv-path`] + [`--out-path`] + [`--description`] + [`--meta`] + [`--xml`] + [`--json`] + [{`--prebuilt-only` | `-b`}] + [{`--attr` | `-A`} *attribute-path*] + +## Description + +The query operation displays information about either the store paths +that are installed in the current generation of the active profile +(`--installed`), or the derivations that are available for installation +in the active Nix expression (`--available`). It only prints information +about derivations whose symbolic name matches one of *names*. + +The derivations are sorted by their `name` attributes. + +## Source selection + +The following flags specify the set of things on which the query +operates. + + - `--installed`\ + The query operates on the store paths that are installed in the + current generation of the active profile. This is the default. + + - `--available`; `-a`\ + The query operates on the derivations that are available in the + active Nix expression. + +## Queries + +The following flags specify what information to display about the +selected derivations. Multiple flags may be specified, in which case the +information is shown in the order given here. Note that the name of the +derivation is shown unless `--no-name` is specified. + + - `--xml`\ + Print the result in an XML representation suitable for automatic + processing by other tools. The root element is called `items`, which + contains a `item` element for each available or installed + derivation. The fields discussed below are all stored in attributes + of the `item` elements. + + - `--json`\ + Print the result in a JSON representation suitable for automatic + processing by other tools. + + - `--prebuilt-only` / `-b`\ + Show only derivations for which a substitute is registered, i.e., + there is a pre-built binary available that can be downloaded in lieu + of building the derivation. Thus, this shows all packages that + probably can be installed quickly. + + - `--status`; `-s`\ + Print the *status* of the derivation. The status consists of three + characters. The first is `I` or `-`, indicating whether the + derivation is currently installed in the current generation of the + active profile. This is by definition the case for `--installed`, + but not for `--available`. The second is `P` or `-`, indicating + whether the derivation is present on the system. This indicates + whether installation of an available derivation will require the + derivation to be built. The third is `S` or `-`, indicating whether + a substitute is available for the derivation. + + - `--attr-path`; `-P`\ + Print the *attribute path* of the derivation, which can be used to + unambiguously select it using the `--attr` option available in + commands that install derivations like `nix-env --install`. This + option only works together with `--available` + + - `--no-name`\ + Suppress printing of the `name` attribute of each derivation. + + - `--compare-versions` / `-c`\ + Compare installed versions to available versions, or vice versa (if + `--available` is given). This is useful for quickly seeing whether + upgrades for installed packages are available in a Nix expression. A + column is added with the following meaning: + + - `<` *version*\ + A newer version of the package is available or installed. + + - `=` *version*\ + At most the same version of the package is available or + installed. + + - `>` *version*\ + Only older versions of the package are available or installed. + + - `- ?`\ + No version of the package is available or installed. + + - `--system`\ + Print the `system` attribute of the derivation. + + - `--drv-path`\ + Print the path of the store derivation. + + - `--out-path`\ + Print the output path of the derivation. + + - `--description`\ + Print a short (one-line) description of the derivation, if + available. The description is taken from the `meta.description` + attribute of the derivation. + + - `--meta`\ + Print all of the meta-attributes of the derivation. This option is + only available with `--xml` or `--json`. + +## Examples + +To show installed packages: + +```console +$ nix-env -q +bison-1.875c +docbook-xml-4.2 +firefox-1.0.4 +MPlayer-1.0pre7 +ORBit2-2.8.3 +… +``` + +To show available packages: + +```console +$ nix-env -qa +firefox-1.0.7 +GConf-2.4.0.1 +MPlayer-1.0pre7 +ORBit2-2.8.3 +… +``` + +To show the status of available packages: + +```console +$ nix-env -qas +-P- firefox-1.0.7 (not installed but present) +--S GConf-2.4.0.1 (not present, but there is a substitute for fast installation) +--S MPlayer-1.0pre3 (i.e., this is not the installed MPlayer, even though the version is the same!) +IP- ORBit2-2.8.3 (installed and by definition present) +… +``` + +To show available packages in the Nix expression `foo.nix`: + +```console +$ nix-env -f ./foo.nix -qa +foo-1.2.3 +``` + +To compare installed versions to what’s available: + +```console +$ nix-env -qc +... +acrobat-reader-7.0 - ? (package is not available at all) +autoconf-2.59 = 2.59 (same version) +firefox-1.0.4 < 1.0.7 (a more recent version is available) +... +``` + +To show all packages with “`zip`” in the name: + +```console +$ nix-env -qa '.*zip.*' +bzip2-1.0.6 +gzip-1.6 +zip-3.0 +… +``` + +To show all packages with “`firefox`” or “`chromium`” in the name: + +```console +$ nix-env -qa '.*(firefox|chromium).*' +chromium-37.0.2062.94 +chromium-beta-38.0.2125.24 +firefox-32.0.3 +firefox-with-plugins-13.0.1 +… +``` + +To show all packages in the latest revision of the Nixpkgs repository: + +```console +$ nix-env -f https://github.com/NixOS/nixpkgs/archive/master.tar.gz -qa +``` + +# Operation `--switch-profile` + +## Synopsis + +`nix-env` {`--switch-profile` | `-S`} *path* + +## Description + +This operation makes *path* the current profile for the user. That is, +the symlink `~/.nix-profile` is made to point to *path*. + +## Examples + +```console +$ nix-env -S ~/my-profile +``` + +# Operation `--list-generations` + +## Synopsis + +`nix-env` `--list-generations` + +## Description + +This operation print a list of all the currently existing generations +for the active profile. These may be switched to using the +`--switch-generation` operation. It also prints the creation date of the +generation, and indicates the current generation. + +## Examples + +```console +$ nix-env --list-generations + 95 2004-02-06 11:48:24 + 96 2004-02-06 11:49:01 + 97 2004-02-06 16:22:45 + 98 2004-02-06 16:24:33 (current) +``` + +# Operation `--delete-generations` + +## Synopsis + +`nix-env` `--delete-generations` *generations* + +## Description + +This operation deletes the specified generations of the current profile. +The generations can be a list of generation numbers, the special value +`old` to delete all non-current generations, a value such as `30d` to +delete all generations older than the specified number of days (except +for the generation that was active at that point in time), or a value +such as `+5` to keep the last `5` generations ignoring any newer than +current, e.g., if `30` is the current generation `+5` will delete +generation `25` and all older generations. Periodically deleting old +generations is important to make garbage collection effective. + +## Examples + +```console +$ nix-env --delete-generations 3 4 8 +``` + +```console +$ nix-env --delete-generations +5 +``` + +```console +$ nix-env --delete-generations 30d +``` + +```console +$ nix-env -p other_profile --delete-generations old +``` + +# Operation `--switch-generation` + +## Synopsis + +`nix-env` {`--switch-generation` | `-G`} *generation* + +## Description + +This operation makes generation number *generation* the current +generation of the active profile. That is, if the `profile` is the path +to the active profile, then the symlink `profile` is made to point to +`profile-generation-link`, which is in turn a symlink to the actual user +environment in the Nix store. + +Switching will fail if the specified generation does not exist. + +## Examples + +```console +$ nix-env -G 42 +switching from generation 50 to 42 +``` + +# Operation `--rollback` + +## Synopsis + +`nix-env` `--rollback` + +## Description + +This operation switches to the “previous” generation of the active +profile, that is, the highest numbered generation lower than the current +generation, if it exists. It is just a convenience wrapper around +`--list-generations` and `--switch-generation`. + +## Examples + +```console +$ nix-env --rollback +switching from generation 92 to 91 +``` + +```console +$ nix-env --rollback +error: no generation older than the current (91) exists +``` + +# Environment variables + + - `NIX_PROFILE`\ + Location of the Nix profile. Defaults to the target of the symlink + `~/.nix-profile`, if it exists, or `/nix/var/nix/profiles/default` + otherwise. diff --git a/doc/manual/src/command-ref/nix-hash.md b/doc/manual/src/command-ref/nix-hash.md new file mode 100644 index 000000000..45f67f1c5 --- /dev/null +++ b/doc/manual/src/command-ref/nix-hash.md @@ -0,0 +1,102 @@ +# Name + +`nix-hash` - compute the cryptographic hash of a path + +# Synopsis + +`nix-hash` [`--flat`] [`--base32`] [`--truncate`] [`--type` *hashAlgo*] *path…* + +`nix-hash` `--to-base16` *hash…* + +`nix-hash` `--to-base32` *hash…* + +# Description + +The command `nix-hash` computes the cryptographic hash of the contents +of each *path* and prints it on standard output. By default, it computes +an MD5 hash, but other hash algorithms are available as well. The hash +is printed in hexadecimal. To generate the same hash as +`nix-prefetch-url` you have to specify multiple arguments, see below for +an example. + +The hash is computed over a *serialisation* of each path: a dump of +the file system tree rooted at the path. This allows directories and +symlinks to be hashed as well as regular files. The dump is in the +*NAR format* produced by [`nix-store +--dump`](nix-store.md#operation---dump). Thus, `nix-hash path` +yields the same cryptographic hash as `nix-store --dump path | +md5sum`. + +# Options + + - `--flat`\ + Print the cryptographic hash of the contents of each regular file + *path*. That is, do not compute the hash over the dump of *path*. + The result is identical to that produced by the GNU commands + `md5sum` and `sha1sum`. + + - `--base32`\ + Print the hash in a base-32 representation rather than hexadecimal. + This base-32 representation is more compact and can be used in Nix + expressions (such as in calls to `fetchurl`). + + - `--truncate`\ + Truncate hashes longer than 160 bits (such as SHA-256) to 160 bits. + + - `--type` *hashAlgo*\ + Use the specified cryptographic hash algorithm, which can be one of + `md5`, `sha1`, `sha256`, and `sha512`. + + - `--to-base16`\ + Don’t hash anything, but convert the base-32 hash representation + *hash* to hexadecimal. + + - `--to-base32`\ + Don’t hash anything, but convert the hexadecimal hash representation + *hash* to base-32. + +# Examples + +Computing the same hash as `nix-prefetch-url`: + +```console +$ nix-prefetch-url file://<(echo test) +1lkgqb6fclns49861dwk9rzb6xnfkxbpws74mxnx01z9qyv1pjpj +$ nix-hash --type sha256 --flat --base32 <(echo test) +1lkgqb6fclns49861dwk9rzb6xnfkxbpws74mxnx01z9qyv1pjpj +``` + +Computing hashes: + +```console +$ mkdir test +$ echo "hello" > test/world + +$ nix-hash test/ (MD5 hash; default) +8179d3caeff1869b5ba1744e5a245c04 + +$ nix-store --dump test/ | md5sum (for comparison) +8179d3caeff1869b5ba1744e5a245c04 - + +$ nix-hash --type sha1 test/ +e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6 + +$ nix-hash --type sha1 --base32 test/ +nvd61k9nalji1zl9rrdfmsmvyyjqpzg4 + +$ nix-hash --type sha256 --flat test/ +error: reading file `test/': Is a directory + +$ nix-hash --type sha256 --flat test/world +5891b5b522d5df086d0ff0b110fbd9d21bb4fc7163af34d08286a2e846f6be03 +``` + +Converting between hexadecimal and base-32: + +```console +$ nix-hash --type sha1 --to-base32 e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6 +nvd61k9nalji1zl9rrdfmsmvyyjqpzg4 + +$ nix-hash --type sha1 --to-base16 nvd61k9nalji1zl9rrdfmsmvyyjqpzg4 +e4fd8ba5f7bbeaea5ace89fe10255536cd60dab6 +``` diff --git a/doc/manual/src/command-ref/nix-instantiate.md b/doc/manual/src/command-ref/nix-instantiate.md new file mode 100644 index 000000000..2e198daed --- /dev/null +++ b/doc/manual/src/command-ref/nix-instantiate.md @@ -0,0 +1,158 @@ +# Name + +`nix-instantiate` - instantiate store derivations from Nix expressions + +# Synopsis + +`nix-instantiate` + [`--parse` | `--eval` [`--strict`] [`--json`] [`--xml`] ] + [`--read-write-mode`] + [`--arg` *name* *value*] + [{`--attr`| `-A`} *attrPath*] + [`--add-root` *path*] + [`--expr` | `-E`] + *files…* + +`nix-instantiate` `--find-file` *files…* + +# Description + +The command `nix-instantiate` generates [store +derivations](../glossary.md) from (high-level) Nix expressions. It +evaluates the Nix expressions in each of *files* (which defaults to +*./default.nix*). Each top-level expression should evaluate to a +derivation, a list of derivations, or a set of derivations. The paths +of the resulting store derivations are printed on standard output. + +If *files* is the character `-`, then a Nix expression will be read from +standard input. + +# Options + + - `--add-root` *path*\ + See the [corresponding option](nix-store.md) in `nix-store`. + + - `--parse`\ + Just parse the input files, and print their abstract syntax trees on + standard output in ATerm format. + + - `--eval`\ + Just parse and evaluate the input files, and print the resulting + values on standard output. No instantiation of store derivations + takes place. + + - `--find-file`\ + Look up the given files in Nix’s search path (as specified by the + `NIX_PATH` environment variable). If found, print the corresponding + absolute paths on standard output. For instance, if `NIX_PATH` is + `nixpkgs=/home/alice/nixpkgs`, then `nix-instantiate --find-file + nixpkgs/default.nix` will print `/home/alice/nixpkgs/default.nix`. + + - `--strict`\ + When used with `--eval`, recursively evaluate list elements and + attributes. Normally, such sub-expressions are left unevaluated + (since the Nix expression language is lazy). + + > **Warning** + > + > This option can cause non-termination, because lazy data + > structures can be infinitely large. + + - `--json`\ + When used with `--eval`, print the resulting value as an JSON + representation of the abstract syntax tree rather than as an ATerm. + + - `--xml`\ + When used with `--eval`, print the resulting value as an XML + representation of the abstract syntax tree rather than as an ATerm. + The schema is the same as that used by the [`toXML` + built-in](../expressions/builtins.md). + + - `--read-write-mode`\ + When used with `--eval`, perform evaluation in read/write mode so + nix language features that require it will still work (at the cost + of needing to do instantiation of every evaluated derivation). If + this option is not enabled, there may be uninstantiated store paths + in the final output. + +<!-- end list --> + +# Examples + +Instantiating store derivations from a Nix expression, and building them +using `nix-store`: + +```console +$ nix-instantiate test.nix (instantiate) +/nix/store/cigxbmvy6dzix98dxxh9b6shg7ar5bvs-perl-BerkeleyDB-0.26.drv + +$ nix-store -r $(nix-instantiate test.nix) (build) +... +/nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26 (output path) + +$ ls -l /nix/store/qhqk4n8ci095g3sdp93x7rgwyh9rdvgk-perl-BerkeleyDB-0.26 +dr-xr-xr-x 2 eelco users 4096 1970-01-01 01:00 lib +... +``` + +You can also give a Nix expression on the command line: + +```console +$ nix-instantiate -E 'with import <nixpkgs> { }; hello' +/nix/store/j8s4zyv75a724q38cb0r87rlczaiag4y-hello-2.8.drv +``` + +This is equivalent to: + +```console +$ nix-instantiate '<nixpkgs>' -A hello +``` + +Parsing and evaluating Nix expressions: + +```console +$ nix-instantiate --parse -E '1 + 2' +1 + 2 +``` + +```console +$ nix-instantiate --eval -E '1 + 2' +3 +``` + +```console +$ nix-instantiate --eval --xml -E '1 + 2' +<?xml version='1.0' encoding='utf-8'?> +<expr> + <int value="3" /> +</expr> +``` + +The difference between non-strict and strict evaluation: + +```console +$ nix-instantiate --eval --xml -E 'rec { x = "foo"; y = x; }' +... + <attr name="x"> + <string value="foo" /> + </attr> + <attr name="y"> + <unevaluated /> + </attr> +... +``` + +Note that `y` is left unevaluated (the XML representation doesn’t +attempt to show non-normal forms). + +```console +$ nix-instantiate --eval --xml --strict -E 'rec { x = "foo"; y = x; }' +... + <attr name="x"> + <string value="foo" /> + </attr> + <attr name="y"> + <string value="foo" /> + </attr> +... +``` diff --git a/doc/manual/src/command-ref/nix-prefetch-url.md b/doc/manual/src/command-ref/nix-prefetch-url.md new file mode 100644 index 000000000..3bcd209e2 --- /dev/null +++ b/doc/manual/src/command-ref/nix-prefetch-url.md @@ -0,0 +1,78 @@ +# Name + +`nix-prefetch-url` - copy a file from a URL into the store and print its hash + +# Synopsis + +`nix-prefetch-url` *url* [*hash*] + [`--type` *hashAlgo*] + [`--print-path`] + [`--unpack`] + [`--name` *name*] + +# Description + +The command `nix-prefetch-url` downloads the file referenced by the URL +*url*, prints its cryptographic hash, and copies it into the Nix store. +The file name in the store is `hash-baseName`, where *baseName* is +everything following the final slash in *url*. + +This command is just a convenience for Nix expression writers. Often a +Nix expression fetches some source distribution from the network using +the `fetchurl` expression contained in Nixpkgs. However, `fetchurl` +requires a cryptographic hash. If you don't know the hash, you would +have to download the file first, and then `fetchurl` would download it +again when you build your Nix expression. Since `fetchurl` uses the same +name for the downloaded file as `nix-prefetch-url`, the redundant +download can be avoided. + +If *hash* is specified, then a download is not performed if the Nix +store already contains a file with the same hash and base name. +Otherwise, the file is downloaded, and an error is signaled if the +actual hash of the file does not match the specified hash. + +This command prints the hash on standard output. Additionally, if the +option `--print-path` is used, the path of the downloaded file in the +Nix store is also printed. + +# Options + + - `--type` *hashAlgo*\ + Use the specified cryptographic hash algorithm, which can be one of + `md5`, `sha1`, `sha256`, and `sha512`. + + - `--print-path`\ + Print the store path of the downloaded file on standard output. + + - `--unpack`\ + Unpack the archive (which must be a tarball or zip file) and add the + result to the Nix store. The resulting hash can be used with + functions such as Nixpkgs’s `fetchzip` or `fetchFromGitHub`. + + - `--executable`\ + Set the executable bit on the downloaded file. + + - `--name` *name*\ + Override the name of the file in the Nix store. By default, this is + `hash-basename`, where *basename* is the last component of *url*. + Overriding the name is necessary when *basename* contains characters + that are not allowed in Nix store paths. + +# Examples + +```console +$ nix-prefetch-url ftp://ftp.gnu.org/pub/gnu/hello/hello-2.10.tar.gz +0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i +``` + +```console +$ nix-prefetch-url --print-path mirror://gnu/hello/hello-2.10.tar.gz +0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i +/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz +``` + +```console +$ nix-prefetch-url --unpack --print-path https://github.com/NixOS/patchelf/archive/0.8.tar.gz +079agjlv0hrv7fxnx9ngipx14gyncbkllxrp9cccnh3a50fxcmy7 +/nix/store/19zrmhm3m40xxaw81c8cqm6aljgrnwj2-0.8.tar.gz +``` diff --git a/doc/manual/src/command-ref/nix-shell.md b/doc/manual/src/command-ref/nix-shell.md new file mode 100644 index 000000000..72f6730f1 --- /dev/null +++ b/doc/manual/src/command-ref/nix-shell.md @@ -0,0 +1,275 @@ +# Name + +`nix-shell` - start an interactive shell based on a Nix expression + +# Synopsis + +`nix-shell` + [`--arg` *name* *value*] + [`--argstr` *name* *value*] + [{`--attr` | `-A`} *attrPath*] + [`--command` *cmd*] + [`--run` *cmd*] + [`--exclude` *regexp*] + [--pure] + [--keep *name*] + {{`--packages` | `-p`} {*packages* | *expressions*} … | [*path*]} + +# Description + +The command `nix-shell` will build the dependencies of the specified +derivation, but not the derivation itself. It will then start an +interactive shell in which all environment variables defined by the +derivation *path* have been set to their corresponding values, and the +script `$stdenv/setup` has been sourced. This is useful for reproducing +the environment of a derivation for development. + +If *path* is not given, `nix-shell` defaults to `shell.nix` if it +exists, and `default.nix` otherwise. + +If *path* starts with `http://` or `https://`, it is interpreted as the +URL of a tarball that will be downloaded and unpacked to a temporary +location. The tarball must include a single top-level directory +containing at least a file named `default.nix`. + +If the derivation defines the variable `shellHook`, it will be run +after `$stdenv/setup` has been sourced. Since this hook is not executed +by regular Nix builds, it allows you to perform initialisation specific +to `nix-shell`. For example, the derivation attribute + +```nix +shellHook = + '' + echo "Hello shell" + export SOME_API_TOKEN="$(cat ~/.config/some-app/api-token)" + ''; +``` + +will cause `nix-shell` to print `Hello shell` and set the `SOME_API_TOKEN` +environment variable to a user-configured value. + +# Options + +All options not listed here are passed to `nix-store +--realise`, except for `--arg` and `--attr` / `-A` which are passed to +`nix-instantiate`. + + - `--command` *cmd*\ + In the environment of the derivation, run the shell command *cmd*. + This command is executed in an interactive shell. (Use `--run` to + use a non-interactive shell instead.) However, a call to `exit` is + implicitly added to the command, so the shell will exit after + running the command. To prevent this, add `return` at the end; + e.g. `--command "echo Hello; return"` will print `Hello` and then + drop you into the interactive shell. This can be useful for doing + any additional initialisation. + + - `--run` *cmd*\ + Like `--command`, but executes the command in a non-interactive + shell. This means (among other things) that if you hit Ctrl-C while + the command is running, the shell exits. + + - `--exclude` *regexp*\ + Do not build any dependencies whose store path matches the regular + expression *regexp*. This option may be specified multiple times. + + - `--pure`\ + If this flag is specified, the environment is almost entirely + cleared before the interactive shell is started, so you get an + environment that more closely corresponds to the “real” Nix build. A + few variables, in particular `HOME`, `USER` and `DISPLAY`, are + retained. + + - `--packages` / `-p` *packages*…\ + Set up an environment in which the specified packages are present. + The command line arguments are interpreted as attribute names inside + the Nix Packages collection. Thus, `nix-shell -p libjpeg openjdk` + will start a shell in which the packages denoted by the attribute + names `libjpeg` and `openjdk` are present. + + - `-i` *interpreter*\ + The chained script interpreter to be invoked by `nix-shell`. Only + applicable in `#!`-scripts (described below). + + - `--keep` *name*\ + When a `--pure` shell is started, keep the listed environment + variables. + +The following common options are supported: + +# Environment variables + + - `NIX_BUILD_SHELL`\ + Shell used to start the interactive environment. Defaults to the + `bash` found in `PATH`. + +# Examples + +To build the dependencies of the package Pan, and start an interactive +shell in which to build it: + +```console +$ nix-shell '<nixpkgs>' -A pan +[nix-shell]$ unpackPhase +[nix-shell]$ cd pan-* +[nix-shell]$ configurePhase +[nix-shell]$ buildPhase +[nix-shell]$ ./pan/gui/pan +``` + +To clear the environment first, and do some additional automatic +initialisation of the interactive shell: + +```console +$ nix-shell '<nixpkgs>' -A pan --pure \ + --command 'export NIX_DEBUG=1; export NIX_CORES=8; return' +``` + +Nix expressions can also be given on the command line using the `-E` and +`-p` flags. For instance, the following starts a shell containing the +packages `sqlite` and `libX11`: + +```console +$ nix-shell -E 'with import <nixpkgs> { }; runCommand "dummy" { buildInputs = [ sqlite xorg.libX11 ]; } ""' +``` + +A shorter way to do the same is: + +```console +$ nix-shell -p sqlite xorg.libX11 +[nix-shell]$ echo $NIX_LDFLAGS +… -L/nix/store/j1zg5v…-sqlite-3.8.0.2/lib -L/nix/store/0gmcz9…-libX11-1.6.1/lib … +``` + +Note that `-p` accepts multiple full nix expressions that are valid in +the `buildInputs = [ ... ]` shown above, not only package names. So the +following is also legal: + +```console +$ nix-shell -p sqlite 'git.override { withManual = false; }' +``` + +The `-p` flag looks up Nixpkgs in the Nix search path. You can override +it by passing `-I` or setting `NIX_PATH`. For example, the following +gives you a shell containing the Pan package from a specific revision of +Nixpkgs: + +```console +$ nix-shell -p pan -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/8a3eea054838b55aca962c3fbde9c83c102b8bf2.tar.gz + +[nix-shell:~]$ pan --version +Pan 0.139 +``` + +# Use as a `#!`-interpreter + +You can use `nix-shell` as a script interpreter to allow scripts written +in arbitrary languages to obtain their own dependencies via Nix. This is +done by starting the script with the following lines: + +```bash +#! /usr/bin/env nix-shell +#! nix-shell -i real-interpreter -p packages +``` + +where *real-interpreter* is the “real” script interpreter that will be +invoked by `nix-shell` after it has obtained the dependencies and +initialised the environment, and *packages* are the attribute names of +the dependencies in Nixpkgs. + +The lines starting with `#! nix-shell` specify `nix-shell` options (see +above). Note that you cannot write `#! /usr/bin/env nix-shell -i ...` +because many operating systems only allow one argument in `#!` lines. + +For example, here is a Python script that depends on Python and the +`prettytable` package: + +```python +#! /usr/bin/env nix-shell +#! nix-shell -i python -p python pythonPackages.prettytable + +import prettytable + +# Print a simple table. +t = prettytable.PrettyTable(["N", "N^2"]) +for n in range(1, 10): t.add_row([n, n * n]) +print t +``` + +Similarly, the following is a Perl script that specifies that it +requires Perl and the `HTML::TokeParser::Simple` and `LWP` packages: + +```perl +#! /usr/bin/env nix-shell +#! nix-shell -i perl -p perl perlPackages.HTMLTokeParserSimple perlPackages.LWP + +use HTML::TokeParser::Simple; + +# Fetch nixos.org and print all hrefs. +my $p = HTML::TokeParser::Simple->new(url => 'http://nixos.org/'); + +while (my $token = $p->get_tag("a")) { + my $href = $token->get_attr("href"); + print "$href\n" if $href; +} +``` + +Sometimes you need to pass a simple Nix expression to customize a +package like Terraform: + +```bash +#! /usr/bin/env nix-shell +#! nix-shell -i bash -p "terraform.withPlugins (plugins: [ plugins.openstack ])" + +terraform apply +``` + +> **Note** +> +> You must use double quotes (`"`) when passing a simple Nix expression +> in a nix-shell shebang. + +Finally, using the merging of multiple nix-shell shebangs the following +Haskell script uses a specific branch of Nixpkgs/NixOS (the 20.03 stable +branch): + +```haskell +#! /usr/bin/env nix-shell +#! nix-shell -i runghc -p "haskellPackages.ghcWithPackages (ps: [ps.download-curl ps.tagsoup])" +#! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-20.03.tar.gz + +import Network.Curl.Download +import Text.HTML.TagSoup +import Data.Either +import Data.ByteString.Char8 (unpack) + +-- Fetch nixos.org and print all hrefs. +main = do + resp <- openURI "https://nixos.org/" + let tags = filter (isTagOpenName "a") $ parseTags $ unpack $ fromRight undefined resp + let tags' = map (fromAttrib "href") tags + mapM_ putStrLn $ filter (/= "") tags' +``` + +If you want to be even more precise, you can specify a specific revision +of Nixpkgs: + + #! nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/0672315759b3e15e2121365f067c1c8c56bb4722.tar.gz + +The examples above all used `-p` to get dependencies from Nixpkgs. You +can also use a Nix expression to build your own dependencies. For +example, the Python example could have been written as: + +```python +#! /usr/bin/env nix-shell +#! nix-shell deps.nix -i python +``` + +where the file `deps.nix` in the same directory as the `#!`-script +contains: + +```nix +with import <nixpkgs> {}; + +runCommand "dummy" { buildInputs = [ python pythonPackages.prettytable ]; } "" +``` diff --git a/doc/manual/src/command-ref/nix-store.md b/doc/manual/src/command-ref/nix-store.md new file mode 100644 index 000000000..7a131dc02 --- /dev/null +++ b/doc/manual/src/command-ref/nix-store.md @@ -0,0 +1,833 @@ +# Name + +`nix-store` - manipulate or query the Nix store + +# Synopsis + +`nix-store` *operation* [*options…*] [*arguments…*] + [`--option` *name* *value*] + [`--add-root` *path*] + +# Description + +The command `nix-store` performs primitive operations on the Nix store. +You generally do not need to run this command manually. + +`nix-store` takes exactly one *operation* flag which indicates the +subcommand to be performed. These are documented below. + +# Common options + +This section lists the options that are common to all operations. These +options are allowed for every subcommand, though they may not always +have an effect. + + - `--add-root` *path*\ + Causes the result of a realisation (`--realise` and + `--force-realise`) to be registered as a root of the garbage + collector. *path* will be created as a symlink to the resulting + store path. In addition, a uniquely named symlink to *path* will + be created in `/nix/var/nix/gcroots/auto/`. For instance, + + ```console + $ nix-store --add-root /home/eelco/bla/result -r ... + + $ ls -l /nix/var/nix/gcroots/auto + lrwxrwxrwx 1 ... 2005-03-13 21:10 dn54lcypm8f8... -> /home/eelco/bla/result + + $ ls -l /home/eelco/bla/result + lrwxrwxrwx 1 ... 2005-03-13 21:10 /home/eelco/bla/result -> /nix/store/1r11343n6qd4...-f-spot-0.0.10 + ``` + + Thus, when `/home/eelco/bla/result` is removed, the GC root in the + `auto` directory becomes a dangling symlink and will be ignored by + the collector. + + > **Warning** + > + > Note that it is not possible to move or rename GC roots, since + > the symlink in the `auto` directory will still point to the old + > location. + + If there are multiple results, then multiple symlinks will be + created by sequentially numbering symlinks beyond the first one + (e.g., `foo`, `foo-2`, `foo-3`, and so on). + +# Operation `--realise` + +## Synopsis + +`nix-store` {`--realise` | `-r`} *paths…* [`--dry-run`] + +## Description + +The operation `--realise` essentially “builds” the specified store +paths. Realisation is a somewhat overloaded term: + + - If the store path is a *derivation*, realisation ensures that the + output paths of the derivation are [valid](../glossary.md) (i.e., + the output path and its closure exist in the file system). This + can be done in several ways. First, it is possible that the + outputs are already valid, in which case we are done + immediately. Otherwise, there may be [substitutes](../glossary.md) + that produce the outputs (e.g., by downloading them). Finally, the + outputs can be produced by performing the build action described + by the derivation. + + - If the store path is not a derivation, realisation ensures that the + specified path is valid (i.e., it and its closure exist in the file + system). If the path is already valid, we are done immediately. + Otherwise, the path and any missing paths in its closure may be + produced through substitutes. If there are no (successful) + substitutes, realisation fails. + +The output path of each derivation is printed on standard output. (For +non-derivations argument, the argument itself is printed.) + +The following flags are available: + + - `--dry-run`\ + Print on standard error a description of what packages would be + built or downloaded, without actually performing the operation. + + - `--ignore-unknown`\ + If a non-derivation path does not have a substitute, then silently + ignore it. + + - `--check`\ + This option allows you to check whether a derivation is + deterministic. It rebuilds the specified derivation and checks + whether the result is bitwise-identical with the existing outputs, + printing an error if that’s not the case. The outputs of the + specified derivation must already exist. When used with `-K`, if an + output path is not identical to the corresponding output from the + previous build, the new output path is left in + `/nix/store/name.check.` + + See also the `build-repeat` configuration option, which repeats a + derivation a number of times and prevents its outputs from being + registered as “valid” in the Nix store unless they are identical. + +Special exit codes: + + - `100`\ + Generic build failure, the builder process returned with a non-zero + exit code. + + - `101`\ + Build timeout, the build was aborted because it did not complete + within the specified `timeout`. + + - `102`\ + Hash mismatch, the build output was rejected because it does not + match the [`outputHash` attribute of the + derivation](../expressions/advanced-attributes.md). + + - `104`\ + Not deterministic, the build succeeded in check mode but the + resulting output is not binary reproducable. + +With the `--keep-going` flag it's possible for multiple failures to +occur, in this case the 1xx status codes are or combined using binary +or. + + 1100100 + ^^^^ + |||`- timeout + ||`-- output hash mismatch + |`--- build failure + `---- not deterministic + +## Examples + +This operation is typically used to build store derivations produced by +[`nix-instantiate`](nix-instantiate.md): + +```console +$ nix-store -r $(nix-instantiate ./test.nix) +/nix/store/31axcgrlbfsxzmfff1gyj1bf62hvkby2-aterm-2.3.1 +``` + +This is essentially what [`nix-build`](nix-build.md) does. + +To test whether a previously-built derivation is deterministic: + +```console +$ nix-build '<nixpkgs>' -A hello --check -K +``` + +# Operation `--serve` + +## Synopsis + +`nix-store` `--serve` [`--write`] + +## Description + +The operation `--serve` provides access to the Nix store over stdin and +stdout, and is intended to be used as a means of providing Nix store +access to a restricted ssh user. + +The following flags are available: + + - `--write`\ + Allow the connected client to request the realization of + derivations. In effect, this can be used to make the host act as a + remote builder. + +## Examples + +To turn a host into a build server, the `authorized_keys` file can be +used to provide build access to a given SSH public key: + +```console +$ cat <<EOF >>/root/.ssh/authorized_keys +command="nice -n20 nix-store --serve --write" ssh-rsa AAAAB3NzaC1yc2EAAAA... +EOF +``` + +# Operation `--gc` + +## Synopsis + +`nix-store` `--gc` [`--print-roots` | `--print-live` | `--print-dead`] [`--max-freed` *bytes*] + +## Description + +Without additional flags, the operation `--gc` performs a garbage +collection on the Nix store. That is, all paths in the Nix store not +reachable via file system references from a set of “roots”, are deleted. + +The following suboperations may be specified: + + - `--print-roots`\ + This operation prints on standard output the set of roots used by + the garbage collector. + + - `--print-live`\ + This operation prints on standard output the set of “live” store + paths, which are all the store paths reachable from the roots. Live + paths should never be deleted, since that would break consistency — + it would become possible that applications are installed that + reference things that are no longer present in the store. + + - `--print-dead`\ + This operation prints out on standard output the set of “dead” store + paths, which is just the opposite of the set of live paths: any path + in the store that is not live (with respect to the roots) is dead. + +By default, all unreachable paths are deleted. The following options +control what gets deleted and in what order: + + - `--max-freed` *bytes*\ + Keep deleting paths until at least *bytes* bytes have been deleted, + then stop. The argument *bytes* can be followed by the + multiplicative suffix `K`, `M`, `G` or `T`, denoting KiB, MiB, GiB + or TiB units. + +The behaviour of the collector is also influenced by the +`keep-outputs` and `keep-derivations` settings in the Nix +configuration file. + +By default, the collector prints the total number of freed bytes when it +finishes (or when it is interrupted). With `--print-dead`, it prints the +number of bytes that would be freed. + +## Examples + +To delete all unreachable paths, just do: + +```console +$ nix-store --gc +deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv' +... +8825586 bytes freed (8.42 MiB) +``` + +To delete at least 100 MiBs of unreachable paths: + +```console +$ nix-store --gc --max-freed $((100 * 1024 * 1024)) +``` + +# Operation `--delete` + +## Synopsis + +`nix-store` `--delete` [`--ignore-liveness`] *paths…* + +## Description + +The operation `--delete` deletes the store paths *paths* from the Nix +store, but only if it is safe to do so; that is, when the path is not +reachable from a root of the garbage collector. This means that you can +only delete paths that would also be deleted by `nix-store --gc`. Thus, +`--delete` is a more targeted version of `--gc`. + +With the option `--ignore-liveness`, reachability from the roots is +ignored. However, the path still won’t be deleted if there are other +paths in the store that refer to it (i.e., depend on it). + +## Example + +```console +$ nix-store --delete /nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4 +0 bytes freed (0.00 MiB) +error: cannot delete path `/nix/store/zq0h41l75vlb4z45kzgjjmsjxvcv1qk7-mesa-6.4' since it is still alive +``` + +# Operation `--query` + +## Synopsis + +`nix-store` {`--query` | `-q`} + {`--outputs` | `--requisites` | `-R` | `--references` | + `--referrers` | `--referrers-closure` | `--deriver` | `-d` | + `--graph` | `--tree` | `--binding` *name* | `-b` *name* | `--hash` | + `--size` | `--roots`} + [`--use-output`] [`-u`] [`--force-realise`] [`-f`] + *paths…* + +## Description + +The operation `--query` displays various bits of information about the +store paths . The queries are described below. At most one query can be +specified. The default query is `--outputs`. + +The paths *paths* may also be symlinks from outside of the Nix store, to +the Nix store. In that case, the query is applied to the target of the +symlink. + +## Common query options + + - `--use-output`; `-u`\ + For each argument to the query that is a store derivation, apply the + query to the output path of the derivation instead. + + - `--force-realise`; `-f`\ + Realise each argument to the query first (see [`nix-store + --realise`](#operation---realise)). + +## Queries + + - `--outputs`\ + Prints out the [output paths](../glossary.md) of the store + derivations *paths*. These are the paths that will be produced when + the derivation is built. + + - `--requisites`; `-R`\ + Prints out the [closure](../glossary.md) of the store path *paths*. + + This query has one option: + + - `--include-outputs` + Also include the output path of store derivations, and their + closures. + + This query can be used to implement various kinds of deployment. A + *source deployment* is obtained by distributing the closure of a + store derivation. A *binary deployment* is obtained by distributing + the closure of an output path. A *cache deployment* (combined + source/binary deployment, including binaries of build-time-only + dependencies) is obtained by distributing the closure of a store + derivation and specifying the option `--include-outputs`. + + - `--references`\ + Prints the set of [references](../glossary.md) of the store paths + *paths*, that is, their immediate dependencies. (For *all* + dependencies, use `--requisites`.) + + - `--referrers`\ + Prints the set of *referrers* of the store paths *paths*, that is, + the store paths currently existing in the Nix store that refer to + one of *paths*. Note that contrary to the references, the set of + referrers is not constant; it can change as store paths are added or + removed. + + - `--referrers-closure`\ + Prints the closure of the set of store paths *paths* under the + referrers relation; that is, all store paths that directly or + indirectly refer to one of *paths*. These are all the path currently + in the Nix store that are dependent on *paths*. + + - `--deriver`; `-d`\ + Prints the [deriver](../glossary.md) of the store paths *paths*. If + the path has no deriver (e.g., if it is a source file), or if the + deriver is not known (e.g., in the case of a binary-only + deployment), the string `unknown-deriver` is printed. + + - `--graph`\ + Prints the references graph of the store paths *paths* in the format + of the `dot` tool of AT\&T's [Graphviz + package](http://www.graphviz.org/). This can be used to visualise + dependency graphs. To obtain a build-time dependency graph, apply + this to a store derivation. To obtain a runtime dependency graph, + apply it to an output path. + + - `--tree`\ + Prints the references graph of the store paths *paths* as a nested + ASCII tree. References are ordered by descending closure size; this + tends to flatten the tree, making it more readable. The query only + recurses into a store path when it is first encountered; this + prevents a blowup of the tree representation of the graph. + + - `--graphml`\ + Prints the references graph of the store paths *paths* in the + [GraphML](http://graphml.graphdrawing.org/) file format. This can be + used to visualise dependency graphs. To obtain a build-time + dependency graph, apply this to a store derivation. To obtain a + runtime dependency graph, apply it to an output path. + + - `--binding` *name*; `-b` *name*\ + Prints the value of the attribute *name* (i.e., environment + variable) of the store derivations *paths*. It is an error for a + derivation to not have the specified attribute. + + - `--hash`\ + Prints the SHA-256 hash of the contents of the store paths *paths* + (that is, the hash of the output of `nix-store --dump` on the given + paths). Since the hash is stored in the Nix database, this is a fast + operation. + + - `--size`\ + Prints the size in bytes of the contents of the store paths *paths* + — to be precise, the size of the output of `nix-store --dump` on + the given paths. Note that the actual disk space required by the + store paths may be higher, especially on filesystems with large + cluster sizes. + + - `--roots`\ + Prints the garbage collector roots that point, directly or + indirectly, at the store paths *paths*. + +## Examples + +Print the closure (runtime dependencies) of the `svn` program in the +current user environment: + +```console +$ nix-store -qR $(which svn) +/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4 +/nix/store/9lz9yc6zgmc0vlqmn2ipcpkjlmbi51vv-glibc-2.3.4 +... +``` + +Print the build-time dependencies of `svn`: + +```console +$ nix-store -qR $(nix-store -qd $(which svn)) +/nix/store/02iizgn86m42q905rddvg4ja975bk2i4-grep-2.5.1.tar.bz2.drv +/nix/store/07a2bzxmzwz5hp58nf03pahrv2ygwgs3-gcc-wrapper.sh +/nix/store/0ma7c9wsbaxahwwl04gbw3fcd806ski4-glibc-2.3.4.drv +... lots of other paths ... +``` + +The difference with the previous example is that we ask the closure of +the derivation (`-qd`), not the closure of the output path that contains +`svn`. + +Show the build-time dependencies as a tree: + +```console +$ nix-store -q --tree $(nix-store -qd $(which svn)) +/nix/store/7i5082kfb6yjbqdbiwdhhza0am2xvh6c-subversion-1.1.4.drv ++---/nix/store/d8afh10z72n8l1cr5w42366abiblgn54-builder.sh ++---/nix/store/fmzxmpjx2lh849ph0l36snfj9zdibw67-bash-3.0.drv +| +---/nix/store/570hmhmx3v57605cqg9yfvvyh0nnb8k8-bash +| +---/nix/store/p3srsbd8dx44v2pg6nbnszab5mcwx03v-builder.sh +... +``` + +Show all paths that depend on the same OpenSSL library as `svn`: + +```console +$ nix-store -q --referrers $(nix-store -q --binding openssl $(nix-store -qd $(which svn))) +/nix/store/23ny9l9wixx21632y2wi4p585qhva1q8-sylpheed-1.0.0 +/nix/store/5mbglq5ldqld8sj57273aljwkfvj22mc-subversion-1.1.4 +/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3 +/nix/store/l51240xqsgg8a7yrbqdx1rfzyv6l26fx-lynx-2.8.5 +``` + +Show all paths that directly or indirectly depend on the Glibc (C +library) used by `svn`: + +```console +$ nix-store -q --referrers-closure $(ldd $(which svn) | grep /libc.so | awk '{print $3}') +/nix/store/034a6h4vpz9kds5r6kzb9lhh81mscw43-libgnomeprintui-2.8.2 +/nix/store/15l3yi0d45prm7a82pcrknxdh6nzmxza-gawk-3.1.4 +... +``` + +Note that `ldd` is a command that prints out the dynamic libraries used +by an ELF executable. + +Make a picture of the runtime dependency graph of the current user +environment: + +```console +$ nix-store -q --graph ~/.nix-profile | dot -Tps > graph.ps +$ gv graph.ps +``` + +Show every garbage collector root that points to a store path that +depends on `svn`: + +```console +$ nix-store -q --roots $(which svn) +/nix/var/nix/profiles/default-81-link +/nix/var/nix/profiles/default-82-link +/nix/var/nix/profiles/per-user/eelco/profile-97-link +``` + +# Operation `--add` + +## Synopsis + +`nix-store` `--add` *paths…* + +## Description + +The operation `--add` adds the specified paths to the Nix store. It +prints the resulting paths in the Nix store on standard output. + +## Example + +```console +$ nix-store --add ./foo.c +/nix/store/m7lrha58ph6rcnv109yzx1nk1cj7k7zf-foo.c +``` + +# Operation `--add-fixed` + +## Synopsis + +`nix-store` `--add-fixed` [`--recursive`] *algorithm* *paths…* + +## Description + +The operation `--add-fixed` adds the specified paths to the Nix store. +Unlike `--add` paths are registered using the specified hashing +algorithm, resulting in the same output path as a fixed-output +derivation. This can be used for sources that are not available from a +public url or broke since the download expression was written. + +This operation has the following options: + + - `--recursive`\ + Use recursive instead of flat hashing mode, used when adding + directories to the store. + +## Example + +```console +$ nix-store --add-fixed sha256 ./hello-2.10.tar.gz +/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz +``` + +# Operation `--verify` + +## Synopsis + +`nix-store` `--verify` [`--check-contents`] [`--repair`] + +## Description + +The operation `--verify` verifies the internal consistency of the Nix +database, and the consistency between the Nix database and the Nix +store. Any inconsistencies encountered are automatically repaired. +Inconsistencies are generally the result of the Nix store or database +being modified by non-Nix tools, or of bugs in Nix itself. + +This operation has the following options: + + - `--check-contents`\ + Checks that the contents of every valid store path has not been + altered by computing a SHA-256 hash of the contents and comparing it + with the hash stored in the Nix database at build time. Paths that + have been modified are printed out. For large stores, + `--check-contents` is obviously quite slow. + + - `--repair`\ + If any valid path is missing from the store, or (if + `--check-contents` is given) the contents of a valid path has been + modified, then try to repair the path by redownloading it. See + `nix-store --repair-path` for details. + +# Operation `--verify-path` + +## Synopsis + +`nix-store` `--verify-path` *paths…* + +## Description + +The operation `--verify-path` compares the contents of the given store +paths to their cryptographic hashes stored in Nix’s database. For every +changed path, it prints a warning message. The exit status is 0 if no +path has changed, and 1 otherwise. + +## Example + +To verify the integrity of the `svn` command and all its dependencies: + +```console +$ nix-store --verify-path $(nix-store -qR $(which svn)) +``` + +# Operation `--repair-path` + +## Synopsis + +`nix-store` `--repair-path` *paths…* + +## Description + +The operation `--repair-path` attempts to “repair” the specified paths +by redownloading them using the available substituters. If no +substitutes are available, then repair is not possible. + +> **Warning** +> +> During repair, there is a very small time window during which the old +> path (if it exists) is moved out of the way and replaced with the new +> path. If repair is interrupted in between, then the system may be left +> in a broken state (e.g., if the path contains a critical system +> component like the GNU C Library). + +## Example + +```console +$ nix-store --verify-path /nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13 +path `/nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13' was modified! + expected hash `2db57715ae90b7e31ff1f2ecb8c12ec1cc43da920efcbe3b22763f36a1861588', + got `481c5aa5483ebc97c20457bb8bca24deea56550d3985cda0027f67fe54b808e4' + +$ nix-store --repair-path /nix/store/dj7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13 +fetching path `/nix/store/d7a81wsm1ijwwpkks3725661h3263p5-glibc-2.13'... +… +``` + +# Operation `--dump` + +## Synopsis + +`nix-store` `--dump` *path* + +## Description + +The operation `--dump` produces a NAR (Nix ARchive) file containing the +contents of the file system tree rooted at *path*. The archive is +written to standard output. + +A NAR archive is like a TAR or Zip archive, but it contains only the +information that Nix considers important. For instance, timestamps are +elided because all files in the Nix store have their timestamp set to 0 +anyway. Likewise, all permissions are left out except for the execute +bit, because all files in the Nix store have 444 or 555 permission. + +Also, a NAR archive is *canonical*, meaning that “equal” paths always +produce the same NAR archive. For instance, directory entries are +always sorted so that the actual on-disk order doesn’t influence the +result. This means that the cryptographic hash of a NAR dump of a +path is usable as a fingerprint of the contents of the path. Indeed, +the hashes of store paths stored in Nix’s database (see `nix-store -q +--hash`) are SHA-256 hashes of the NAR dump of each store path. + +NAR archives support filenames of unlimited length and 64-bit file +sizes. They can contain regular files, directories, and symbolic links, +but not other types of files (such as device nodes). + +A Nix archive can be unpacked using `nix-store +--restore`. + +# Operation `--restore` + +## Synopsis + +`nix-store` `--restore` *path* + +## Description + +The operation `--restore` unpacks a NAR archive to *path*, which must +not already exist. The archive is read from standard input. + +# Operation `--export` + +## Synopsis + +`nix-store` `--export` *paths…* + +## Description + +The operation `--export` writes a serialisation of the specified store +paths to standard output in a format that can be imported into another +Nix store with `nix-store --import`. This is like `nix-store +--dump`, except that the NAR archive produced by that command doesn’t +contain the necessary meta-information to allow it to be imported into +another Nix store (namely, the set of references of the path). + +This command does not produce a *closure* of the specified paths, so if +a store path references other store paths that are missing in the target +Nix store, the import will fail. To copy a whole closure, do something +like: + +```console +$ nix-store --export $(nix-store -qR paths) > out +``` + +To import the whole closure again, run: + +```console +$ nix-store --import < out +``` + +# Operation `--import` + +## Synopsis + +`nix-store` `--import` + +## Description + +The operation `--import` reads a serialisation of a set of store paths +produced by `nix-store --export` from standard input and adds those +store paths to the Nix store. Paths that already exist in the Nix store +are ignored. If a path refers to another path that doesn’t exist in the +Nix store, the import fails. + +# Operation `--optimise` + +## Synopsis + +`nix-store` `--optimise` + +## Description + +The operation `--optimise` reduces Nix store disk space usage by finding +identical files in the store and hard-linking them to each other. It +typically reduces the size of the store by something like 25-35%. Only +regular files and symlinks are hard-linked in this manner. Files are +considered identical when they have the same NAR archive serialisation: +that is, regular files must have the same contents and permission +(executable or non-executable), and symlinks must have the same +contents. + +After completion, or when the command is interrupted, a report on the +achieved savings is printed on standard error. + +Use `-vv` or `-vvv` to get some progress indication. + +## Example + +```console +$ nix-store --optimise +hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1' +... +541838819 bytes (516.74 MiB) freed by hard-linking 54143 files; +there are 114486 files with equal contents out of 215894 files in total +``` + +# Operation `--read-log` + +## Synopsis + +`nix-store` {`--read-log` | `-l`} *paths…* + +## Description + +The operation `--read-log` prints the build log of the specified store +paths on standard output. The build log is whatever the builder of a +derivation wrote to standard output and standard error. If a store path +is not a derivation, the deriver of the store path is used. + +Build logs are kept in `/nix/var/log/nix/drvs`. However, there is no +guarantee that a build log is available for any particular store path. +For instance, if the path was downloaded as a pre-built binary through a +substitute, then the log is unavailable. + +## Example + +```console +$ nix-store -l $(which ktorrent) +building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1 +unpacking sources +unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz +ktorrent-2.2.1/ +ktorrent-2.2.1/NEWS +... +``` + +# Operation `--dump-db` + +## Synopsis + +`nix-store` `--dump-db` [*paths…*] + +## Description + +The operation `--dump-db` writes a dump of the Nix database to standard +output. It can be loaded into an empty Nix store using `--load-db`. This +is useful for making backups and when migrating to different database +schemas. + +By default, `--dump-db` will dump the entire Nix database. When one or +more store paths is passed, only the subset of the Nix database for +those store paths is dumped. As with `--export`, the user is responsible +for passing all the store paths for a closure. See `--export` for an +example. + +# Operation `--load-db` + +## Synopsis + +`nix-store` `--load-db` + +## Description + +The operation `--load-db` reads a dump of the Nix database created by +`--dump-db` from standard input and loads it into the Nix database. + +# Operation `--print-env` + +## Synopsis + +`nix-store` `--print-env` *drvpath* + +## Description + +The operation `--print-env` prints out the environment of a derivation +in a format that can be evaluated by a shell. The command line arguments +of the builder are placed in the variable `_args`. + +## Example + +```console +$ nix-store --print-env $(nix-instantiate '<nixpkgs>' -A firefox) +… +export src; src='/nix/store/plpj7qrwcz94z2psh6fchsi7s8yihc7k-firefox-12.0.source.tar.bz2' +export stdenv; stdenv='/nix/store/7c8asx3yfrg5dg1gzhzyq2236zfgibnn-stdenv' +export system; system='x86_64-linux' +export _args; _args='-e /nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25c-default-builder.sh' +``` + +# Operation `--generate-binary-cache-key` + +## Synopsis + +`nix-store` `--generate-binary-cache-key` *key-name* *secret-key-file* *public-key-file* + +## Description + +This command generates an [Ed25519 key pair](http://ed25519.cr.yp.to/) +that can be used to create a signed binary cache. It takes three +mandatory parameters: + +1. A key name, such as `cache.example.org-1`, that is used to look up + keys on the client when it verifies signatures. It can be anything, + but it’s suggested to use the host name of your cache (e.g. + `cache.example.org`) with a suffix denoting the number of the key + (to be incremented every time you need to revoke a key). + +2. The file name where the secret key is to be stored. + +3. The file name where the public key is to be stored. diff --git a/doc/manual/src/command-ref/opt-common-syn.md b/doc/manual/src/command-ref/opt-common-syn.md new file mode 100644 index 000000000..b66d318c2 --- /dev/null +++ b/doc/manual/src/command-ref/opt-common-syn.md @@ -0,0 +1,57 @@ +\--help + +\--version + +\--verbose + +\-v + +\--quiet + +\--log-format + +format + +\--no-build-output + +\-Q + +\--max-jobs + +\-j + +number + +\--cores + +number + +\--max-silent-time + +number + +\--timeout + +number + +\--keep-going + +\-k + +\--keep-failed + +\-K + +\--fallback + +\--readonly-mode + +\-I + +path + +\--option + +name + +value diff --git a/doc/manual/src/command-ref/opt-common.md b/doc/manual/src/command-ref/opt-common.md new file mode 100644 index 000000000..47862bc09 --- /dev/null +++ b/doc/manual/src/command-ref/opt-common.md @@ -0,0 +1,219 @@ +# Common Options + +Most Nix commands accept the following command-line options: + + - `--help`\ + Prints out a summary of the command syntax and exits. + + - `--version`\ + Prints out the Nix version number on standard output and exits. + + - `--verbose` / `-v`\ + Increases the level of verbosity of diagnostic messages printed on + standard error. For each Nix operation, the information printed on + standard output is well-defined; any diagnostic information is + printed on standard error, never on standard output. + + This option may be specified repeatedly. Currently, the following + verbosity levels exist: + + - 0\ + “Errors only”: only print messages explaining why the Nix + invocation failed. + + - 1\ + “Informational”: print *useful* messages about what Nix is + doing. This is the default. + + - 2\ + “Talkative”: print more informational messages. + + - 3\ + “Chatty”: print even more informational messages. + + - 4\ + “Debug”: print debug information. + + - 5\ + “Vomit”: print vast amounts of debug information. + + - `--quiet`\ + Decreases the level of verbosity of diagnostic messages printed on + standard error. This is the inverse option to `-v` / `--verbose`. + + This option may be specified repeatedly. See the previous verbosity + levels list. + + - `--log-format` *format*\ + This option can be used to change the output of the log format, with + *format* being one of: + + - raw\ + This is the raw format, as outputted by nix-build. + + - internal-json\ + Outputs the logs in a structured manner. + + > **Warning** + > + > While the schema itself is relatively stable, the format of + > the error-messages (namely of the `msg`-field) can change + > between releases. + + - bar\ + Only display a progress bar during the builds. + + - bar-with-logs\ + Display the raw logs, with the progress bar at the bottom. + + - `--no-build-output` / `-Q`\ + By default, output written by builders to standard output and + standard error is echoed to the Nix command's standard error. This + option suppresses this behaviour. Note that the builder's standard + output and error are always written to a log file in + `prefix/nix/var/log/nix`. + + - `--max-jobs` / `-j` *number*\ + Sets the maximum number of build jobs that Nix will perform in + parallel to the specified number. Specify `auto` to use the number + of CPUs in the system. The default is specified by the `max-jobs` + configuration setting, which itself defaults to `1`. A higher + value is useful on SMP systems or to exploit I/O latency. + + Setting it to `0` disallows building on the local machine, which is + useful when you want builds to happen only on remote builders. + + - `--cores`\ + Sets the value of the `NIX_BUILD_CORES` environment variable in + the invocation of builders. Builders can use this variable at + their discretion to control the maximum amount of parallelism. For + instance, in Nixpkgs, if the derivation attribute + `enableParallelBuilding` is set to `true`, the builder passes the + `-jN` flag to GNU Make. It defaults to the value of the `cores` + configuration setting, if set, or `1` otherwise. The value `0` + means that the builder should use all available CPU cores in the + system. + + - `--max-silent-time`\ + Sets the maximum number of seconds that a builder can go without + producing any data on standard output or standard error. The + default is specified by the `max-silent-time` configuration + setting. `0` means no time-out. + + - `--timeout`\ + Sets the maximum number of seconds that a builder can run. The + default is specified by the `timeout` configuration setting. `0` + means no timeout. + + - `--keep-going` / `-k`\ + Keep going in case of failed builds, to the greatest extent + possible. That is, if building an input of some derivation fails, + Nix will still build the other inputs, but not the derivation + itself. Without this option, Nix stops if any build fails (except + for builds of substitutes), possibly killing builds in progress (in + case of parallel or distributed builds). + + - `--keep-failed` / `-K`\ + Specifies that in case of a build failure, the temporary directory + (usually in `/tmp`) in which the build takes place should not be + deleted. The path of the build directory is printed as an + informational message. + + - `--fallback`\ + Whenever Nix attempts to build a derivation for which substitutes + are known for each output path, but realising the output paths + through the substitutes fails, fall back on building the derivation. + + The most common scenario in which this is useful is when we have + registered substitutes in order to perform binary distribution from, + say, a network repository. If the repository is down, the + realisation of the derivation will fail. When this option is + specified, Nix will build the derivation instead. Thus, installation + from binaries falls back on installation from source. This option is + not the default since it is generally not desirable for a transient + failure in obtaining the substitutes to lead to a full build from + source (with the related consumption of resources). + + - `--readonly-mode`\ + When this option is used, no attempt is made to open the Nix + database. Most Nix operations do need database access, so those + operations will fail. + + - `--arg` *name* *value*\ + This option is accepted by `nix-env`, `nix-instantiate`, + `nix-shell` and `nix-build`. When evaluating Nix expressions, the + expression evaluator will automatically try to call functions that + it encounters. It can automatically call functions for which every + argument has a [default + value](../expressions/language-constructs.md#functions) (e.g., + `{ argName ? defaultValue }: ...`). With `--arg`, you can also + call functions that have arguments without a default value (or + override a default value). That is, if the evaluator encounters a + function with an argument named *name*, it will call it with value + *value*. + + For instance, the top-level `default.nix` in Nixpkgs is actually a + function: + + ```nix + { # The system (e.g., `i686-linux') for which to build the packages. + system ? builtins.currentSystem + ... + }: ... + ``` + + So if you call this Nix expression (e.g., when you do `nix-env -i + pkgname`), the function will be called automatically using the + value [`builtins.currentSystem`](../expressions/builtins.md) for + the `system` argument. You can override this using `--arg`, e.g., + `nix-env -i pkgname --arg system \"i686-freebsd\"`. (Note that + since the argument is a Nix string literal, you have to escape the + quotes.) + + - `--argstr` *name* *value*\ + This option is like `--arg`, only the value is not a Nix + expression but a string. So instead of `--arg system + \"i686-linux\"` (the outer quotes are to keep the shell happy) you + can say `--argstr system i686-linux`. + + - `--attr` / `-A` *attrPath*\ + Select an attribute from the top-level Nix expression being + evaluated. (`nix-env`, `nix-instantiate`, `nix-build` and + `nix-shell` only.) The *attribute path* *attrPath* is a sequence + of attribute names separated by dots. For instance, given a + top-level Nix expression *e*, the attribute path `xorg.xorgserver` + would cause the expression `e.xorg.xorgserver` to be used. See + [`nix-env --install`](nix-env.md#operation---install) for some + concrete examples. + + In addition to attribute names, you can also specify array indices. + For instance, the attribute path `foo.3.bar` selects the `bar` + attribute of the fourth element of the array in the `foo` attribute + of the top-level expression. + + - `--expr` / `-E`\ + Interpret the command line arguments as a list of Nix expressions to + be parsed and evaluated, rather than as a list of file names of Nix + expressions. (`nix-instantiate`, `nix-build` and `nix-shell` only.) + + For `nix-shell`, this option is commonly used to give you a shell in + which you can build the packages returned by the expression. If you + want to get a shell which contain the *built* packages ready for + use, give your expression to the `nix-shell -p` convenience flag + instead. + + - `-I` *path*\ + Add a path to the Nix expression search path. This option may be + given multiple times. See the `NIX_PATH` environment variable for + information on the semantics of the Nix search path. Paths added + through `-I` take precedence over `NIX_PATH`. + + - `--option` *name* *value*\ + Set the Nix configuration option *name* to *value*. This overrides + settings in the Nix configuration file (see nix.conf5). + + - `--repair`\ + Fix corrupted or missing store paths by redownloading or rebuilding + them. Note that this is slow because it requires computing a + cryptographic hash of the contents of every path in the closure of + the build. Also note the warning under `nix-store --repair-path`. diff --git a/doc/manual/src/command-ref/opt-inst-syn.md b/doc/manual/src/command-ref/opt-inst-syn.md new file mode 100644 index 000000000..1703c40e3 --- /dev/null +++ b/doc/manual/src/command-ref/opt-inst-syn.md @@ -0,0 +1,15 @@ +\--prebuilt-only + +\-b + +\--attr + +\-A + +\--from-expression + +\-E + +\--from-profile + +path diff --git a/doc/manual/src/command-ref/utilities.md b/doc/manual/src/command-ref/utilities.md new file mode 100644 index 000000000..5ba8a02a3 --- /dev/null +++ b/doc/manual/src/command-ref/utilities.md @@ -0,0 +1,3 @@ +# Utilities + +This section lists utilities that you can use when you work with Nix. |