1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
#include "environment-variables.hh"
#include "file-system.hh"
#include "logging.hh"
#include "strings.hh"
#include <pwd.h>
#include <sys/types.h>
#include <unistd.h>
namespace nix {
std::string getUserName()
{
auto pw = getpwuid(geteuid());
std::string name = pw ? pw->pw_name : getEnv("USER").value_or("");
if (name.empty())
throw Error("cannot figure out user name");
return name;
}
Path getHomeOf(uid_t userId)
{
std::vector<char> buf(16384);
struct passwd pwbuf;
struct passwd * pw;
if (getpwuid_r(userId, &pwbuf, buf.data(), buf.size(), &pw) != 0
|| !pw || !pw->pw_dir || !pw->pw_dir[0])
throw Error("cannot determine user's home directory");
return pw->pw_dir;
}
Path getHome()
{
static Path homeDir = []()
{
std::optional<std::string> unownedUserHomeDir = {};
auto homeDir = getEnv("HOME");
if (homeDir) {
// Only use `$HOME` if it exists and is owned by the current user.
struct stat st;
int result = stat(homeDir->c_str(), &st);
if (result != 0) {
if (errno != ENOENT) {
warn("couldn't stat $HOME ('%s') for reason other than not existing ('%d'), falling back to the one defined in the 'passwd' file", *homeDir, errno);
homeDir.reset();
}
} else if (st.st_uid != geteuid()) {
unownedUserHomeDir.swap(homeDir);
}
}
if (!homeDir) {
homeDir = getHomeOf(geteuid());
if (unownedUserHomeDir.has_value() && unownedUserHomeDir != homeDir) {
warn("$HOME ('%s') is not owned by you, falling back to the one defined in the 'passwd' file ('%s')", *unownedUserHomeDir, *homeDir);
}
}
return *homeDir;
}();
return homeDir;
}
Path getCacheDir()
{
auto cacheDir = getEnv("XDG_CACHE_HOME");
return cacheDir ? *cacheDir : getHome() + "/.cache";
}
Path getConfigDir()
{
auto configDir = getEnv("XDG_CONFIG_HOME");
return configDir ? *configDir : getHome() + "/.config";
}
std::vector<Path> getConfigDirs()
{
Path configHome = getConfigDir();
auto configDirs = getEnv("XDG_CONFIG_DIRS").value_or("/etc/xdg");
std::vector<Path> result = tokenizeString<std::vector<std::string>>(configDirs, ":");
result.insert(result.begin(), configHome);
return result;
}
Path getDataDir()
{
auto dataDir = getEnv("XDG_DATA_HOME");
return dataDir ? *dataDir : getHome() + "/.local/share";
}
Path getStateDir()
{
auto stateDir = getEnv("XDG_STATE_HOME");
return stateDir ? *stateDir : getHome() + "/.local/state";
}
Path createNixStateDir()
{
Path dir = getStateDir() + "/nix";
createDirs(dir);
return dir;
}
}
|
