Replace readline by linenoise

Using linenoise avoids a license compatibility issue (#1356), is a lot
smaller and doesn't pull in ncurses.

10 files changed, 1377 insertions, 132 deletions

diff --git a/configure.ac b/configure.ac
index ac37456ae..c7026cf95 100644
--- a/configure.ac
+++ b/configure.ac
@@ -196,14 +196,6 @@ if test "$gc" = yes; then
 fi
 
 
-# Check for readline, needed by "nix repl".
-AX_LIB_READLINE
-if test "$ax_cv_lib_readline" != "no"; then
-  have_readline=1
-fi
-AC_SUBST(HAVE_READLINE, [$have_readline])
-
-
 AC_ARG_ENABLE(init-state, AC_HELP_STRING([--disable-init-state],
   [do not initialise DB etc. in `make install']),
   init_state=$enableval, init_state=yes)
diff --git a/doc/manual/introduction/about-nix.xml b/doc/manual/introduction/about-nix.xml
index e6dfb7a5a..be065da3e 100644
--- a/doc/manual/introduction/about-nix.xml
+++ b/doc/manual/introduction/about-nix.xml
@@ -261,6 +261,12 @@ xlink:href="http://nixos.org/">NixOS homepage</link>.</para>
 xlink:href="http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html">GNU
 LGPLv2.1 or (at your option) any later version</link>.</para>
 
+<para>Nix uses the <link
+xlink:href="https://github.com/antirez/linenoise">linenoise
+library</link>, which has the following license:</para>
+
+<programlisting><xi:include href="../../../src/linenoise/LICENSE" parse="text" /></programlisting>
+
 </simplesect>
 
 
diff --git a/nix.spec.in b/nix.spec.in
index 3ba2dfc94..390893d64 100644
--- a/nix.spec.in
+++ b/nix.spec.in
@@ -20,11 +20,9 @@ Requires: curl
 Requires: bzip2
 Requires: gzip
 Requires: xz
-Requires: readline
 BuildRequires: bzip2-devel
 BuildRequires: sqlite-devel
 BuildRequires: libcurl-devel
-BuildRequires: readline-devel
 
 # Hack to make that shitty RPM scanning hack shut up.
 Provides: perl(Nix::SSH)
diff --git a/release.nix b/release.nix
index fa2fde4f6..54d20c868 100644
--- a/release.nix
+++ b/release.nix
@@ -73,7 +73,7 @@ let
         buildInputs =
           [ curl
             bzip2 xz brotli
-            openssl pkgconfig sqlite boehmgc readline
+            openssl pkgconfig sqlite boehmgc
 
           ]
           ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
@@ -198,15 +198,15 @@ let
     rpm_fedora25x86_64 = makeRPM_x86_64 (diskImageFunsFun: diskImageFunsFun.fedora25x86_64) [ "libsodium-devel" ];
 
 
-    deb_debian8i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.debian8i386) [ "libsodium-dev" ] [ "libsodium13" "libreadline6" ];
-    deb_debian8x86_64 = makeDeb_x86_64 (diskImageFunsFun: diskImageFunsFun.debian8x86_64) [ "libsodium-dev" ] [ "libsodium13" "libreadline6" ];
+    deb_debian8i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.debian8i386) [ "libsodium-dev" ] [ "libsodium13" ];
+    deb_debian8x86_64 = makeDeb_x86_64 (diskImageFunsFun: diskImageFunsFun.debian8x86_64) [ "libsodium-dev" ] [ "libsodium13" ];
 
-    deb_ubuntu1410i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1410i386) [] [ "libreadline6" ];
-    deb_ubuntu1410x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1410x86_64) [] [ "libreadline6" ];
-    deb_ubuntu1604i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1604i386) [ "libsodium-dev" ] [ "libsodium18" "libreadline6" ];
-    deb_ubuntu1604x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1604x86_64) [ "libsodium-dev" ] [ "libsodium18" "libreadline6" ];
-    deb_ubuntu1610i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1610i386) [ "libsodium-dev" ] [ "libsodium18" "libreadline7" ];
-    deb_ubuntu1610x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1610x86_64) [ "libsodium-dev" ] [ "libsodium18" "libreadline7" ];
+    deb_ubuntu1410i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1410i386) [] [];
+    deb_ubuntu1410x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1410x86_64) [] [];
+    deb_ubuntu1604i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1604i386) [ "libsodium-dev" ] [ "libsodium18" ];
+    deb_ubuntu1604x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1604x86_64) [ "libsodium-dev" ] [ "libsodium18" ];
+    deb_ubuntu1610i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1610i386) [ "libsodium-dev" ] [ "libsodium18" ];
+    deb_ubuntu1610x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1610x86_64) [ "libsodium-dev" ] [ "libsodium18" ];
 
 
     # System tests.
@@ -299,7 +299,7 @@ let
       src = jobs.tarball;
       diskImage = (diskImageFun vmTools.diskImageFuns)
         { extraPackages =
-            [ "sqlite" "sqlite-devel" "bzip2-devel" "emacs" "libcurl-devel" "openssl-devel" "xz-devel" "readline-devel" ]
+            [ "sqlite" "sqlite-devel" "bzip2-devel" "emacs" "libcurl-devel" "openssl-devel" "xz-devel" ]
             ++ extraPackages; };
       memSize = 1024;
       meta.schedulingPriority = 50;
@@ -321,7 +321,7 @@ let
       src = jobs.tarball;
       diskImage = (diskImageFun vmTools.diskImageFuns)
         { extraPackages =
-            [ "libsqlite3-dev" "libbz2-dev" "libcurl-dev" "libcurl3-nss" "libssl-dev" "liblzma-dev" "libreadline-dev" ]
+            [ "libsqlite3-dev" "libbz2-dev" "libcurl-dev" "libcurl3-nss" "libssl-dev" "liblzma-dev" ]
             ++ extraPackages; };
       memSize = 1024;
       meta.schedulingPriority = 50;
diff --git a/shell.nix b/shell.nix
index bbce68564..8645d3602 100644
--- a/shell.nix
+++ b/shell.nix
@@ -16,7 +16,6 @@ with import <nixpkgs> {};
         customMemoryManagement = false;
       })
       autoreconfHook
-      readline
 
       # For nix-perl
       perl
diff --git a/src/linenoise/LICENSE b/src/linenoise/LICENSE
new file mode 100644
index 000000000..18e814865
--- /dev/null
+++ b/src/linenoise/LICENSE
@@ -0,0 +1,25 @@
+Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/src/linenoise/linenoise.c b/src/linenoise/linenoise.c
new file mode 100644
index 000000000..fce14a7c5
--- /dev/null
+++ b/src/linenoise/linenoise.c
@@ -0,0 +1,1199 @@
+/* linenoise.c -- guerrilla line editing library against the idea that a
+ * line editing lib needs to be 20,000 lines of C code.
+ *
+ * You can find the latest source code at:
+ *
+ *   http://github.com/antirez/linenoise
+ *
+ * Does a number of crazy assumptions that happen to be true in 99.9999% of
+ * the 2010 UNIX computers around.
+ *
+ * ------------------------------------------------------------------------
+ *
+ * Copyright (c) 2010-2016, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  *  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *  *  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ------------------------------------------------------------------------
+ *
+ * References:
+ * - http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
+ * - http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
+ *
+ * Todo list:
+ * - Filter bogus Ctrl+<char> combinations.
+ * - Win32 support
+ *
+ * Bloat:
+ * - History search like Ctrl+r in readline?
+ *
+ * List of escape sequences used by this program, we do everything just
+ * with three sequences. In order to be so cheap we may have some
+ * flickering effect with some slow terminal, but the lesser sequences
+ * the more compatible.
+ *
+ * EL (Erase Line)
+ *    Sequence: ESC [ n K
+ *    Effect: if n is 0 or missing, clear from cursor to end of line
+ *    Effect: if n is 1, clear from beginning of line to cursor
+ *    Effect: if n is 2, clear entire line
+ *
+ * CUF (CUrsor Forward)
+ *    Sequence: ESC [ n C
+ *    Effect: moves cursor forward n chars
+ *
+ * CUB (CUrsor Backward)
+ *    Sequence: ESC [ n D
+ *    Effect: moves cursor backward n chars
+ *
+ * The following is used to get the terminal width if getting
+ * the width with the TIOCGWINSZ ioctl fails
+ *
+ * DSR (Device Status Report)
+ *    Sequence: ESC [ 6 n
+ *    Effect: reports the current cusor position as ESC [ n ; m R
+ *            where n is the row and m is the column
+ *
+ * When multi line mode is enabled, we also use an additional escape
+ * sequence. However multi line editing is disabled by default.
+ *
+ * CUU (Cursor Up)
+ *    Sequence: ESC [ n A
+ *    Effect: moves cursor up of n chars.
+ *
+ * CUD (Cursor Down)
+ *    Sequence: ESC [ n B
+ *    Effect: moves cursor down of n chars.
+ *
+ * When linenoiseClearScreen() is called, two additional escape sequences
+ * are used in order to clear the screen and position the cursor at home
+ * position.
+ *
+ * CUP (Cursor position)
+ *    Sequence: ESC [ H
+ *    Effect: moves the cursor to upper left corner
+ *
+ * ED (Erase display)
+ *    Sequence: ESC [ 2 J
+ *    Effect: clear the whole screen
+ *
+ */
+
+#include <termios.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include "linenoise.h"
+
+#define LINENOISE_DEFAULT_HISTORY_MAX_LEN 100
+#define LINENOISE_MAX_LINE 4096
+static char *unsupported_term[] = {"dumb","cons25","emacs",NULL};
+static linenoiseCompletionCallback *completionCallback = NULL;
+static linenoiseHintsCallback *hintsCallback = NULL;
+static linenoiseFreeHintsCallback *freeHintsCallback = NULL;
+
+static struct termios orig_termios; /* In order to restore at exit.*/
+static int rawmode = 0; /* For atexit() function to check if restore is needed*/
+static int mlmode = 0;  /* Multi line mode. Default is single line. */
+static int atexit_registered = 0; /* Register atexit just 1 time. */
+static int history_max_len = LINENOISE_DEFAULT_HISTORY_MAX_LEN;
+static int history_len = 0;
+static char **history = NULL;
+
+/* The linenoiseState structure represents the state during line editing.
+ * We pass this state to functions implementing specific editing
+ * functionalities. */
+struct linenoiseState {
+    int ifd;            /* Terminal stdin file descriptor. */
+    int ofd;            /* Terminal stdout file descriptor. */
+    char *buf;          /* Edited line buffer. */
+    size_t buflen;      /* Edited line buffer size. */
+    const char *prompt; /* Prompt to display. */
+    size_t plen;        /* Prompt length. */
+    size_t pos;         /* Current cursor position. */
+    size_t oldpos;      /* Previous refresh cursor position. */
+    size_t len;         /* Current edited line length. */
+    size_t cols;        /* Number of columns in terminal. */
+    size_t maxrows;     /* Maximum num of rows used so far (multiline mode) */
+    int history_index;  /* The history index we are currently editing. */
+};
+
+enum KEY_ACTION{
+	KEY_NULL = 0,	    /* NULL */
+	CTRL_A = 1,         /* Ctrl+a */
+	CTRL_B = 2,         /* Ctrl-b */
+	CTRL_C = 3,         /* Ctrl-c */
+	CTRL_D = 4,         /* Ctrl-d */
+	CTRL_E = 5,         /* Ctrl-e */
+	CTRL_F = 6,         /* Ctrl-f */
+	CTRL_H = 8,         /* Ctrl-h */
+	TAB = 9,            /* Tab */
+	CTRL_K = 11,        /* Ctrl+k */
+	CTRL_L = 12,        /* Ctrl+l */
+	ENTER = 13,         /* Enter */
+	CTRL_N = 14,        /* Ctrl-n */
+	CTRL_P = 16,        /* Ctrl-p */
+	CTRL_T = 20,        /* Ctrl-t */
+	CTRL_U = 21,        /* Ctrl+u */
+	CTRL_W = 23,        /* Ctrl+w */
+	ESC = 27,           /* Escape */
+	BACKSPACE =  127    /* Backspace */
+};
+
+static void linenoiseAtExit(void);
+int linenoiseHistoryAdd(const char *line);
+static void refreshLine(struct linenoiseState *l);
+
+/* Debugging macro. */
+#if 0
+FILE *lndebug_fp = NULL;
+#define lndebug(...) \
+    do { \
+        if (lndebug_fp == NULL) { \
+            lndebug_fp = fopen("/tmp/lndebug.txt","a"); \
+            fprintf(lndebug_fp, \
+            "[%d %d %d] p: %d, rows: %d, rpos: %d, max: %d, oldmax: %d\n", \
+            (int)l->len,(int)l->pos,(int)l->oldpos,plen,rows,rpos, \
+            (int)l->maxrows,old_rows); \
+        } \
+        fprintf(lndebug_fp, ", " __VA_ARGS__); \
+        fflush(lndebug_fp); \
+    } while (0)
+#else
+#define lndebug(fmt, ...)
+#endif
+
+/* ======================= Low level terminal handling ====================== */
+
+/* Set if to use or not the multi line mode. */
+void linenoiseSetMultiLine(int ml) {
+    mlmode = ml;
+}
+
+/* Return true if the terminal name is in the list of terminals we know are
+ * not able to understand basic escape sequences. */
+static int isUnsupportedTerm(void) {
+    char *term = getenv("TERM");
+    int j;
+
+    if (term == NULL) return 0;
+    for (j = 0; unsupported_term[j]; j++)
+        if (!strcasecmp(term,unsupported_term[j])) return 1;
+    return 0;
+}
+
+/* Raw mode: 1960 magic shit. */
+static int enableRawMode(int fd) {
+    struct termios raw;
+
+    if (!isatty(STDIN_FILENO)) goto fatal;
+    if (!atexit_registered) {
+        atexit(linenoiseAtExit);
+        atexit_registered = 1;
+    }
+    if (tcgetattr(fd,&orig_termios) == -1) goto fatal;
+
+    raw = orig_termios;  /* modify the original mode */
+    /* input modes: no break, no CR to NL, no parity check, no strip char,
+     * no start/stop output control. */
+    raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+    /* output modes - disable post processing */
+    raw.c_oflag &= ~(OPOST);
+    /* control modes - set 8 bit chars */
+    raw.c_cflag |= (CS8);
+    /* local modes - choing off, canonical off, no extended functions,
+     * no signal chars (^Z,^C) */
+    raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+    /* control chars - set return condition: min number of bytes and timer.
+     * We want read to return every single byte, without timeout. */
+    raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
+
+    /* put terminal in raw mode after flushing */
+    if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
+    rawmode = 1;
+    return 0;
+
+fatal:
+    errno = ENOTTY;
+    return -1;
+}
+
+static void disableRawMode(int fd) {
+    /* Don't even check the return value as it's too late. */
+    if (rawmode && tcsetattr(fd,TCSAFLUSH,&orig_termios) != -1)
+        rawmode = 0;
+}
+
+/* Use the ESC [6n escape sequence to query the horizontal cursor position
+ * and return it. On error -1 is returned, on success the position of the
+ * cursor. */
+static int getCursorPosition(int ifd, int ofd) {
+    char buf[32];
+    int cols, rows;
+    unsigned int i = 0;
+
+    /* Report cursor location */
+    if (write(ofd, "\x1b[6n", 4) != 4) return -1;
+
+    /* Read the response: ESC [ rows ; cols R */
+    while (i < sizeof(buf)-1) {
+        if (read(ifd,buf+i,1) != 1) break;
+        if (buf[i] == 'R') break;
+        i++;
+    }
+    buf[i] = '\0';
+
+    /* Parse it. */
+    if (buf[0] != ESC || buf[1] != '[') return -1;
+    if (sscanf(buf+2,"%d;%d",&rows,&cols) != 2) return -1;
+    return cols;
+}
+
+/* Try to get the number of columns in the current terminal, or assume 80
+ * if it fails. */
+static int getColumns(int ifd, int ofd) {
+    struct winsize ws;
+
+    if (ioctl(1, TIOCGWINSZ, &ws) == -1 || ws.ws_col == 0) {
+        /* ioctl() failed. Try to query the terminal itself. */
+        int start, cols;
+
+        /* Get the initial position so we can restore it later. */
+        start = getCursorPosition(ifd,ofd);
+        if (start == -1) goto failed;
+
+        /* Go to right margin and get position. */
+        if (write(ofd,"\x1b[999C",6) != 6) goto failed;
+        cols = getCursorPosition(ifd,ofd);
+        if (cols == -1) goto failed;
+
+        /* Restore position. */
+        if (cols > start) {
+            char seq[32];
+            snprintf(seq,32,"\x1b[%dD",cols-start);
+            if (write(ofd,seq,strlen(seq)) == -1) {
+                /* Can't recover... */
+            }
+        }
+        return cols;
+    } else {
+        return ws.ws_col;
+    }
+
+failed:
+    return 80;
+}
+
+/* Clear the screen. Used to handle ctrl+l */
+void linenoiseClearScreen(void) {
+    if (write(STDOUT_FILENO,"\x1b[H\x1b[2J",7) <= 0) {
+        /* nothing to do, just to avoid warning. */
+    }
+}
+
+/* Beep, used for completion when there is nothing to complete or when all
+ * the choices were already shown. */
+static void linenoiseBeep(void) {
+    fprintf(stderr, "\x7");
+    fflush(stderr);
+}
+
+/* ============================== Completion ================================ */
+
+/* Free a list of completion option populated by linenoiseAddCompletion(). */
+static void freeCompletions(linenoiseCompletions *lc) {
+    size_t i;
+    for (i = 0; i < lc->len; i++)
+        free(lc->cvec[i]);
+    if (lc->cvec != NULL)
+        free(lc->cvec);
+}
+
+/* This is an helper function for linenoiseEdit() and is called when the
+ * user types the <tab> key in order to complete the string currently in the
+ * input.
+ *
+ * The state of the editing is encapsulated into the pointed linenoiseState
+ * structure as described in the structure definition. */
+static int completeLine(struct linenoiseState *ls) {
+    linenoiseCompletions lc = { 0, NULL };
+    int nread, nwritten;
+    char c = 0;
+
+    completionCallback(ls->buf,&lc);
+    if (lc.len == 0) {
+        linenoiseBeep();
+    } else {
+        size_t stop = 0, i = 0;
+
+        while(!stop) {
+            /* Show completion or original buffer */
+            if (i < lc.len) {
+                struct linenoiseState saved = *ls;
+
+                ls->len = ls->pos = strlen(lc.cvec[i]);
+                ls->buf = lc.cvec[i];
+                refreshLine(ls);
+                ls->len = saved.len;
+                ls->pos = saved.pos;
+                ls->buf = saved.buf;
+            } else {
+                refreshLine(ls);
+            }
+
+            nread = read(ls->ifd,&c,1);
+            if (nread <= 0) {
+                freeCompletions(&lc);
+                return -1;
+            }
+
+            switch(c) {
+                case 9: /* tab */
+                    i = (i+1) % (lc.len+1);
+                    if (i == lc.len) linenoiseBeep();
+                    break;
+                case 27: /* escape */
+                    /* Re-show original buffer */
+                    if (i < lc.len) refreshLine(ls);
+                    stop = 1;
+                    break;
+                default:
+                    /* Update buffer and return */
+                    if (i < lc.len) {
+                        nwritten = snprintf(ls->buf,ls->buflen,"%s",lc.cvec[i]);
+                        ls->len = ls->pos = nwritten;
+                    }
+                    stop = 1;
+                    break;
+            }
+        }
+    }
+
+    freeCompletions(&lc);
+    return c; /* Return last read character */
+}
+
+/* Register a callback function to be called for tab-completion. */
+void linenoiseSetCompletionCallback(linenoiseCompletionCallback *fn) {
+    completionCallback = fn;
+}
+
+/* Register a hits function to be called to show hits to the user at the
+ * right of the prompt. */
+void linenoiseSetHintsCallback(linenoiseHintsCallback *fn) {
+    hintsCallback = fn;
+}
+
+/* Register a function to free the hints returned by the hints callback
+ * registered with linenoiseSetHintsCallback(). */
+void linenoiseSetFreeHintsCallback(linenoiseFreeHintsCallback *fn) {
+    freeHintsCallback = fn;
+}
+
+/* This function is used by the callback function registered by the user
+ * in order to add completion options given the input string when the
+ * user typed <tab>. See the example.c source code for a very easy to
+ * understand example. */
+void linenoiseAddCompletion(linenoiseCompletions *lc, const char *str) {
+    size_t len = strlen(str);
+    char *copy, **cvec;
+
+    copy = malloc(len+1);
+    if (copy == NULL) return;
+    memcpy(copy,str,len+1);
+    cvec = realloc(lc->cvec,sizeof(char*)*(lc->len+1));
+    if (cvec == NULL) {
+        free(copy);
+        return;
+    }
+    lc->cvec = cvec;
+    lc->cvec[lc->len++] = copy;
+}
+
+/* =========================== Line editing ================================= */
+
+/* We define a very simple "append buffer" structure, that is an heap
+ * allocated string where we can append to. This is useful in order to
+ * write all the escape sequences in a buffer and flush them to the standard
+ * output in a single call, to avoid flickering effects. */
+struct abuf {
+    char *b;
+    int len;
+};
+
+static void abInit(struct abuf *ab) {
+    ab->b = NULL;
+    ab->len = 0;
+}
+
+static void abAppend(struct abuf *ab, const char *s, int len) {
+    char *new = realloc(ab->b,ab->len+len);
+
+    if (new == NULL) return;
+    memcpy(new+ab->len,s,len);
+    ab->b = new;
+    ab->len += len;
+}
+
+static void abFree(struct abuf *ab) {
+    free(ab->b);
+}
+
+/* Helper of refreshSingleLine() and refreshMultiLine() to show hints
+ * to the right of the prompt. */
+void refreshShowHints(struct abuf *ab, struct linenoiseState *l, int plen) {
+    char seq[64];
+    if (hintsCallback && plen+l->len < l->cols) {
+        int color = -1, bold = 0;
+        char *hint = hintsCallback(l->buf,&color,&bold);
+        if (hint) {
+            int hintlen = strlen(hint);
+            int hintmaxlen = l->cols-(plen+l->len);
+            if (hintlen > hintmaxlen) hintlen = hintmaxlen;
+            if (bold == 1 && color == -1) color = 37;
+            if (color != -1 || bold != 0)
+                snprintf(seq,64,"\033[%d;%d;49m",bold,color);
+            abAppend(ab,seq,strlen(seq));
+            abAppend(ab,hint,hintlen);
+            if (color != -1 || bold != 0)
+                abAppend(ab,"\033[0m",4);
+            /* Call the function to free the hint returned. */
+            if (freeHintsCallback) freeHintsCallback(hint);
+        }
+    }
+}
+
+/* Single line low level line refresh.
+ *
+ * Rewrite the currently edited line accordingly to the buffer content,
+ * cursor position, and number of columns of the terminal. */
+static void refreshSingleLine(struct linenoiseState *l) {
+    char seq[64];
+    size_t plen = strlen(l->prompt);
+    int fd = l->ofd;
+    char *buf = l->buf;
+    size_t len = l->len;
+    size_t pos = l->pos;
+    struct abuf ab;
+
+    while((plen+pos) >= l->cols) {
+        buf++;
+        len--;
+        pos--;
+    }
+    while (plen+len > l->cols) {
+        len--;
+    }
+
+    abInit(&ab);
+    /* Cursor to left edge */
+    snprintf(seq,64,"\r");
+    abAppend(&ab,seq,strlen(seq));
+    /* Write the prompt and the current buffer content */
+    abAppend(&ab,l->prompt,strlen(l->prompt));
+    abAppend(&ab,buf,len);
+    /* Show hits if any. */
+    refreshShowHints(&ab,l,plen);
+    /* Erase to right */
+    snprintf(seq,64,"\x1b[0K");
+    abAppend(&ab,seq,strlen(seq));
+    /* Move cursor to original position. */
+    snprintf(seq,64,"\r\x1b[%dC", (int)(pos+plen));
+    abAppend(&ab,seq,strlen(seq));
+    if (write(fd,ab.b,ab.len) == -1) {} /* Can't recover from write error. */
+    abFree(&ab);
+}
+
+/* Multi line low level line refresh.
+ *
+ * Rewrite the currently edited line accordingly to the buffer content,
+ * cursor position, and number of columns of the terminal. */
+static void refreshMultiLine(struct linenoiseState *l) {
+    char seq[64];
+    int plen = strlen(l->prompt);
+    int rows = (plen+l->len+l->cols-1)/l->cols; /* rows used by current buf. */
+    int rpos = (plen+l->oldpos+l->cols)/l->cols; /* cursor relative row. */
+    int rpos2; /* rpos after refresh. */
+    int col; /* colum position, zero-based. */
+    int old_rows = l->maxrows;
+    int fd = l->ofd, j;
+    struct abuf ab;
+
+    /* Update maxrows if needed. */
+    if (rows > (int)l->maxrows) l->maxrows = rows;
+
+    /* First step: clear all the lines used before. To do so start by
+     * going to the last row. */
+    abInit(&ab);
+    if (old_rows-rpos > 0) {
+        lndebug("go down %d", old_rows-rpos);
+        snprintf(seq,64,"\x1b[%dB", old_rows-rpos);
+        abAppend(&ab,seq,strlen(seq));
+    }
+
+    /* Now for every row clear it, go up. */
+    for (j = 0; j < old_rows-1; j++) {
+        lndebug("clear+up");
+        snprintf(seq,64,"\r\x1b[0K\x1b[1A");
+        abAppend(&ab,seq,strlen(seq));
+    }
+
+    /* Clean the top line. */
+    lndebug("clear");
+    snprintf(seq,64,"\r\x1b[0K");
+    abAppend(&ab,seq,strlen(seq));
+
+    /* Write the prompt and the current buffer content */
+    abAppend(&ab,l->prompt,strlen(l->prompt));
+    abAppend(&ab,l->buf,l->len);
+
+    /* Show hits if any. */
+    refreshShowHints(&ab,l,plen);
+
+    /* If we are at the very end of the screen with our prompt, we need to
+     * emit a newline and move the prompt to the first column. */
+    if (l->pos &&
+        l->pos == l->len &&
+        (l->pos+plen) % l->cols == 0)
+    {
+        lndebug("<newline>");
+        abAppend(&ab,"\n",1);
+        snprintf(seq,64,"\r");
+        abAppend(&ab,seq,strlen(seq));
+        rows++;
+        if (rows > (int)l->maxrows) l->maxrows = rows;
+    }
+
+    /* Move cursor to right position. */
+    rpos2 = (plen+l->pos+l->cols)/l->cols; /* current cursor relative row. */
+    lndebug("rpos2 %d", rpos2);
+
+    /* Go up till we reach the expected positon. */
+    if (rows-rpos2 > 0) {
+        lndebug("go-up %d", rows-rpos2);
+        snprintf(seq,64,"\x1b[%dA", rows-rpos2);
+        abAppend(&ab,seq,strlen(seq));
+    }
+
+    /* Set column. */
+    col = (plen+(int)l->pos) % (int)l->cols;
+    lndebug("set col %d", 1+col);
+    if (col)
+        snprintf(seq,64,"\r\x1b[%dC", col);
+    else
+        snprintf(seq,64,"\r");
+    abAppend(&ab,seq,strlen(seq));
+
+    lndebug("\n");
+    l->oldpos = l->pos;
+
+    if (write(fd,ab.b,ab.len) == -1) {} /* Can't recover from write error. */
+    abFree(&ab);
+}
+
+/* Calls the two low level functions refreshSingleLine() or
+ * refreshMultiLine() according to the selected mode. */
+static void refreshLine(struct linenoiseState *l) {
+    if (mlmode)
+        refreshMultiLine(l);
+    else
+        refreshSingleLine(l);
+}
+
+/* Insert the character 'c' at cursor current position.
+ *
+ * On error writing to the terminal -1 is returned, otherwise 0. */
+int linenoiseEditInsert(struct linenoiseState *l, char c) {
+    if (l->len < l->buflen) {
+        if (l->len == l->pos) {
+            l->buf[l->pos] = c;
+            l->pos++;
+            l->len++;
+            l->buf[l->len] = '\0';
+            if ((!mlmode && l->plen+l->len < l->cols && !hintsCallback)) {
+                /* Avoid a full update of the line in the
+                 * trivial case. */
+                if (write(l->ofd,&c,1) == -1) return -1;
+            } else {
+                refreshLine(l);
+            }
+        } else {
+            memmove(l->buf+l->pos+1,l->buf+l->pos,l->len-l->pos);
+            l->buf[l->pos] = c;
+            l->len++;
+            l->pos++;
+            l->buf[l->len] = '\0';
+            refreshLine(l);
+        }
+    }
+    return 0;
+}
+
+/* Move cursor on the left. */
+void linenoiseEditMoveLeft(struct linenoiseState *l) {
+    if (l->pos > 0) {
+        l->pos--;
+        refreshLine(l);
+    }
+}
+
+/* Move cursor on the right. */
+void linenoiseEditMoveRight(struct linenoiseState *l) {
+    if (l->pos != l->len) {
+        l->pos++;
+        refreshLine(l);
+    }
+}
+
+/* Move cursor to the start of the line. */
+void linenoiseEditMoveHome(struct linenoiseState *l) {
+    if (l->pos != 0) {
+        l->pos = 0;
+        refreshLine(l);
+    }
+}
+
+/* Move cursor to the end of the line. */
+void linenoiseEditMoveEnd(struct linenoiseState *l) {
+    if (l->pos != l->len) {
+        l->pos = l->len;
+        refreshLine(l);
+    }
+}
+
+/* Substitute the currently edited line with the next or previous history
+ * entry as specified by 'dir'. */
+#define LINENOISE_HISTORY_NEXT 0
+#define LINENOISE_HISTORY_PREV 1
+void linenoiseEditHistoryNext(struct linenoiseState *l, int dir) {
+    if (history_len > 1) {
+        /* Update the current history entry before to
+         * overwrite it with the next one. */
+        free(history[history_len - 1 - l->history_index]);
+        history[history_len - 1 - l->history_index] = strdup(l->buf);
+        /* Show the new entry */
+        l->history_index += (dir == LINENOISE_HISTORY_PREV) ? 1 : -1;
+        if (l->history_index < 0) {
+            l->history_index = 0;
+            return;
+        } else if (l->history_index >= history_len) {
+            l->history_index = history_len-1;
+            return;
+        }
+        strncpy(l->buf,history[history_len - 1 - l->history_index],l->buflen);
+        l->buf[l->buflen-1] = '\0';
+        l->len = l->pos = strlen(l->buf);
+        refreshLine(l);
+    }
+}
+
+/* Delete the character at the right of the cursor without altering the cursor
+ * position. Basically this is what happens with the "Delete" keyboard key. */
+void linenoiseEditDelete(struct linenoiseState *l) {
+    if (l->len > 0 && l->pos < l->len) {
+        memmove(l->buf+l->pos,l->buf+l->pos+1,l->len-l->pos-1);
+        l->len--;
+        l->buf[l->len] = '\0';
+        refreshLine(l);
+    }
+}
+
+/* Backspace implementation. */
+void linenoiseEditBackspace(struct linenoiseState *l) {
+    if (l->pos > 0 && l->len > 0) {
+        memmove(l->buf+l->pos-1,l->buf+l->pos,l->len-l->pos);
+        l->pos--;
+        l->len--;
+        l->buf[l->len] = '\0';
+        refreshLine(l);
+    }
+}
+
+/* Delete the previosu word, maintaining the cursor at the start of the
+ * current word. */
+void linenoiseEditDeletePrevWord(struct linenoiseState *l) {
+    size_t old_pos = l->pos;
+    size_t diff;
+
+    while (l->pos > 0 && l->buf[l->pos-1] == ' ')
+        l->pos--;
+    while (l->pos > 0 && l->buf[l->pos-1] != ' ')
+        l->pos--;
+    diff = old_pos - l->pos;
+    memmove(l->buf+l->pos,l->buf+old_pos,l->len-old_pos+1);
+    l->len -= diff;
+    refreshLine(l);
+}
+
+/* This function is the core of the line editing capability of linenoise.
+ * It expects 'fd' to be already in "raw mode" so that every key pressed
+ * will be returned ASAP to read().
+ *
+ * The resulting string is put into 'buf' when the user type enter, or
+ * when ctrl+d is typed.
+ *
+ * The function returns the length of the current buffer. */
+static int linenoiseEdit(int stdin_fd, int stdout_fd, char *buf, size_t buflen, const char *prompt)
+{
+    struct linenoiseState l;
+
+    /* Populate the linenoise state that we pass to functions implementing
+     * specific editing functionalities. */
+    l.ifd = stdin_fd;
+    l.ofd = stdout_fd;
+    l.buf = buf;
+    l.buflen = buflen;
+    l.prompt = prompt;
+    l.plen = strlen(prompt);
+    l.oldpos = l.pos = 0;
+    l.len = 0;
+    l.cols = getColumns(stdin_fd, stdout_fd);
+    l.maxrows = 0;
+    l.history_index = 0;
+
+    /* Buffer starts empty. */
+    l.buf[0] = '\0';
+    l.buflen--; /* Make sure there is always space for the nulterm */
+
+    /* The latest history entry is always our current buffer, that
+     * initially is just an empty string. */
+    linenoiseHistoryAdd("");
+
+    if (write(l.ofd,prompt,l.plen) == -1) return -1;
+    while(1) {
+        char c;
+        int nread;
+        char seq[3];
+
+        nread = read(l.ifd,&c,1);
+        if (nread <= 0) return l.len;
+
+        /* Only autocomplete when the callback is set. It returns < 0 when
+         * there was an error reading from fd. Otherwise it will return the
+         * character that should be handled next. */
+        if (c == 9 && completionCallback != NULL) {
+            c = completeLine(&l);
+            /* Return on errors */
+            if (c < 0) return l.len;
+            /* Read next character when 0 */
+            if (c == 0) continue;
+        }
+
+        switch(c) {
+        case ENTER:    /* enter */
+            history_len--;
+            free(history[history_len]);
+            if (mlmode) linenoiseEditMoveEnd(&l);
+            if (hintsCallback) {
+                /* Force a refresh without hints to leave the previous
+                 * line as the user typed it after a newline. */
+                linenoiseHintsCallback *hc = hintsCallback;
+                hintsCallback = NULL;
+                refreshLine(&l);
+                hintsCallback = hc;
+            }
+            return (int)l.len;
+        case CTRL_C:     /* ctrl-c */
+            errno = EAGAIN;
+            return -1;
+        case BACKSPACE:   /* backspace */
+        case 8:     /* ctrl-h */
+            linenoiseEditBackspace(&l);
+            break;
+        case CTRL_D:     /* ctrl-d, remove char at right of cursor, or if the
+                            line is empty, act as end-of-file. */
+            if (l.len > 0) {
+                linenoiseEditDelete(&l);
+            } else {
+                history_len--;
+                free(history[history_len]);
+                return -1;
+            }
+            break;
+        case CTRL_T:    /* ctrl-t, swaps current character with previous. */
+            if (l.pos > 0 && l.pos < l.len) {
+                int aux = buf[l.pos-1];
+                buf[l.pos-1] = buf[l.pos];
+                buf[l.pos] = aux;
+                if (l.pos != l.len-1) l.pos++;
+                refreshLine(&l);
+            }
+            break;
+        case CTRL_B:     /* ctrl-b */
+            linenoiseEditMoveLeft(&l);
+            break;
+        case CTRL_F:     /* ctrl-f */
+            linenoiseEditMoveRight(&l);
+            break;
+        case CTRL_P:    /* ctrl-p */
+            linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV);
+            break;
+        case CTRL_N:    /* ctrl-n */
+            linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT);
+            break;
+        case ESC:    /* escape sequence */
+            /* Read the next two bytes representing the escape sequence.
+             * Use two calls to handle slow terminals returning the two
+             * chars at different times. */
+            if (read(l.ifd,seq,1) == -1) break;
+            if (read(l.ifd,seq+1,1) == -1) break;
+
+            /* ESC [ sequences. */
+            if (seq[0] == '[') {
+                if (seq[1] >= '0' && seq[1] <= '9') {
+                    /* Extended escape, read additional byte. */
+                    if (read(l.ifd,seq+2,1) == -1) break;
+                    if (seq[2] == '~') {
+                        switch(seq[1]) {
+                        case '3': /* Delete key. */
+                            linenoiseEditDelete(&l);
+                            break;
+                        }
+                    }
+                } else {
+                    switch(seq[1]) {
+                    case 'A': /* Up */
+                        linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_PREV);
+                        break;
+                    case 'B': /* Down */
+                        linenoiseEditHistoryNext(&l, LINENOISE_HISTORY_NEXT);
+                        break;
+                    case 'C': /* Right */
+                        linenoiseEditMoveRight(&l);
+                        break;
+                    case 'D': /* Left */
+                        linenoiseEditMoveLeft(&l);
+                        break;
+                    case 'H': /* Home */
+                        linenoiseEditMoveHome(&l);
+                        break;
+                    case 'F': /* End*/
+                        linenoiseEditMoveEnd(&l);
+                        break;
+                    }
+                }
+            }
+
+            /* ESC O sequences. */
+            else if (seq[0] == 'O') {
+                switch(seq[1]) {
+                case 'H': /* Home */
+                    linenoiseEditMoveHome(&l);
+                    break;
+                case 'F': /* End*/
+                    linenoiseEditMoveEnd(&l);
+                    break;
+                }
+            }
+            break;
+        default:
+            if (linenoiseEditInsert(&l,c)) return -1;
+            break;
+        case CTRL_U: /* Ctrl+u, delete the whole line. */
+            buf[0] = '\0';
+            l.pos = l.len = 0;
+            refreshLine(&l);
+            break;
+        case CTRL_K: /* Ctrl+k, delete from current to end of line. */
+            buf[l.pos] = '\0';
+            l.len = l.pos;
+            refreshLine(&l);
+            break;
+        case CTRL_A: /* Ctrl+a, go to the start of the line */
+            linenoiseEditMoveHome(&l);
+            break;
+        case CTRL_E: /* ctrl+e, go to the end of the line */
+            linenoiseEditMoveEnd(&l);
+            break;
+        case CTRL_L: /* ctrl+l, clear screen */
+            linenoiseClearScreen();
+            refreshLine(&l);
+            break;
+        case CTRL_W: /* ctrl+w, delete previous word */
+            linenoiseEditDeletePrevWord(&l);
+            break;
+        }
+    }
+    return l.len;
+}
+
+/* This special mode is used by linenoise in order to print scan codes
+ * on screen for debugging / development purposes. It is implemented
+ * by the linenoise_example program using the --keycodes option. */
+void linenoisePrintKeyCodes(void) {
+    char quit[4];
+
+    printf("Linenoise key codes debugging mode.\n"
+            "Press keys to see scan codes. Type 'quit' at any time to exit.\n");
+    if (enableRawMode(STDIN_FILENO) == -1) return;
+    memset(quit,' ',4);
+    while(1) {
+        char c;
+        int nread;
+
+        nread = read(STDIN_FILENO,&c,1);
+        if (nread <= 0) continue;
+        memmove(quit,quit+1,sizeof(quit)-1); /* shift string to left. */
+        quit[sizeof(quit)-1] = c; /* Insert current char on the right. */
+        if (memcmp(quit,"quit",sizeof(quit)) == 0) break;
+
+        printf("'%c' %02x (%d) (type quit to exit)\n",
+            isprint(c) ? c : '?', (int)c, (int)c);
+        printf("\r"); /* Go left edge manually, we are in raw mode. */
+        fflush(stdout);
+    }
+    disableRawMode(STDIN_FILENO);
+}
+
+/* This function calls the line editing function linenoiseEdit() using
+ * the STDIN file descriptor set in raw mode. */
+static int linenoiseRaw(char *buf, size_t buflen, const char *prompt) {
+    int count;
+
+    if (buflen == 0) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if (enableRawMode(STDIN_FILENO) == -1) return -1;
+    count = linenoiseEdit(STDIN_FILENO, STDOUT_FILENO, buf, buflen, prompt);
+    disableRawMode(STDIN_FILENO);
+    printf("\n");
+    return count;
+}
+
+/* This function is called when linenoise() is called with the standard
+ * input file descriptor not attached to a TTY. So for example when the
+ * program using linenoise is called in pipe or with a file redirected
+ * to its standard input. In this case, we want to be able to return the
+ * line regardless of its length (by default we are limited to 4k). */
+static char *linenoiseNoTTY(void) {
+    char *line = NULL;
+    size_t len = 0, maxlen = 0;
+
+    while(1) {
+        if (len == maxlen) {
+            if (maxlen == 0) maxlen = 16;
+            maxlen *= 2;
+            char *oldval = line;
+            line = realloc(line,maxlen);
+            if (line == NULL) {
+                if (oldval) free(oldval);
+                return NULL;
+            }
+        }
+        int c = fgetc(stdin);
+        if (c == EOF || c == '\n') {
+            if (c == EOF && len == 0) {
+                free(line);
+                return NULL;
+            } else {
+                line[len] = '\0';
+                return line;
+            }
+        } else {
+            line[len] = c;
+            len++;
+        }
+    }
+}
+
+/* The high level function that is the main API of the linenoise library.
+ * This function checks if the terminal has basic capabilities, just checking
+ * for a blacklist of stupid terminals, and later either calls the line
+ * editing function or uses dummy fgets() so that you will be able to type
+ * something even in the most desperate of the conditions. */
+char *linenoise(const char *prompt) {
+    char buf[LINENOISE_MAX_LINE];
+    int count;
+
+    if (!isatty(STDIN_FILENO)) {
+        /* Not a tty: read from file / pipe. In this mode we don't want any
+         * limit to the line size, so we call a function to handle that. */
+        return linenoiseNoTTY();
+    } else if (isUnsupportedTerm()) {
+        size_t len;
+
+        printf("%s",prompt);
+        fflush(stdout);
+        if (fgets(buf,LINENOISE_MAX_LINE,stdin) == NULL) return NULL;
+        len = strlen(buf);
+        while(len && (buf[len-1] == '\n' || buf[len-1] == '\r')) {
+            len--;
+            buf[len] = '\0';
+        }
+        return strdup(buf);
+    } else {
+        count = linenoiseRaw(buf,LINENOISE_MAX_LINE,prompt);
+        if (count == -1) return NULL;
+        return strdup(buf);
+    }
+}
+
+/* This is just a wrapper the user may want to call in order to make sure
+ * the linenoise returned buffer is freed with the same allocator it was
+ * created with. Useful when the main program is using an alternative
+ * allocator. */
+void linenoiseFree(void *ptr) {
+    free(ptr);
+}
+
+/* ================================ History ================================= */
+
+/* Free the history, but does not reset it. Only used when we have to
+ * exit() to avoid memory leaks are reported by valgrind & co. */
+static void freeHistory(void) {
+    if (history) {
+        int j;
+
+        for (j = 0; j < history_len; j++)
+            free(history[j]);
+        free(history);
+    }
+}
+
+/* At exit we'll try to fix the terminal to the initial conditions. */
+static void linenoiseAtExit(void) {
+    disableRawMode(STDIN_FILENO);
+    freeHistory();
+}
+
+/* This is the API call to add a new entry in the linenoise history.
+ * It uses a fixed array of char pointers that are shifted (memmoved)
+ * when the history max length is reached in order to remove the older
+ * entry and make room for the new one, so it is not exactly suitable for huge
+ * histories, but will work well for a few hundred of entries.
+ *
+ * Using a circular buffer is smarter, but a bit more complex to handle. */
+int linenoiseHistoryAdd(const char *line) {
+    char *linecopy;
+
+    if (history_max_len == 0) return 0;
+
+    /* Initialization on first call. */
+    if (history == NULL) {
+        history = malloc(sizeof(char*)*history_max_len);
+        if (history == NULL) return 0;
+        memset(history,0,(sizeof(char*)*history_max_len));
+    }
+
+    /* Don't add duplicated lines. */
+    if (history_len && !strcmp(history[history_len-1], line)) return 0;
+
+    /* Add an heap allocated copy of the line in the history.
+     * If we reached the max length, remove the older line. */
+    linecopy = strdup(line);
+    if (!linecopy) return 0;
+    if (history_len == history_max_len) {
+        free(history[0]);
+        memmove(history,history+1,sizeof(char*)*(history_max_len-1));
+        history_len--;
+    }
+    history[history_len] = linecopy;
+    history_len++;
+    return 1;
+}
+
+/* Set the maximum length for the history. This function can be called even
+ * if there is already some history, the function will make sure to retain
+ * just the latest 'len' elements if the new history length value is smaller
+ * than the amount of items already inside the history. */
+int linenoiseHistorySetMaxLen(int len) {
+    char **new;
+
+    if (len < 1) return 0;
+    if (history) {
+        int tocopy = history_len;
+
+        new = malloc(sizeof(char*)*len);
+        if (new == NULL) return 0;
+
+        /* If we can't copy everything, free the elements we'll not use. */
+        if (len < tocopy) {
+            int j;
+
+            for (j = 0; j < tocopy-len; j++) free(history[j]);
+            tocopy = len;
+        }
+        memset(new,0,sizeof(char*)*len);
+        memcpy(new,history+(history_len-tocopy), sizeof(char*)*tocopy);
+        free(history);
+        history = new;
+    }
+    history_max_len = len;
+    if (history_len > history_max_len)
+        history_len = history_max_len;
+    return 1;
+}
+
+/* Save the history in the specified file. On success 0 is returned
+ * otherwise -1 is returned. */
+int linenoiseHistorySave(const char *filename) {
+    mode_t old_umask = umask(S_IXUSR|S_IRWXG|S_IRWXO);
+    FILE *fp;
+    int j;
+
+    fp = fopen(filename,"w");
+    umask(old_umask);
+    if (fp == NULL) return -1;
+    chmod(filename,S_IRUSR|S_IWUSR);
+    for (j = 0; j < history_len; j++)
+        fprintf(fp,"%s\n",history[j]);
+    fclose(fp);
+    return 0;
+}
+
+/* Load the history from the specified file. If the file does not exist
+ * zero is returned and no operation is performed.
+ *
+ * If the file exists and the operation succeeded 0 is returned, otherwise
+ * on error -1 is returned. */
+int linenoiseHistoryLoad(const char *filename) {
+    FILE *fp = fopen(filename,"r");
+    char buf[LINENOISE_MAX_LINE];
+
+    if (fp == NULL) return -1;
+
+    while (fgets(buf,LINENOISE_MAX_LINE,fp) != NULL) {
+        char *p;
+
+        p = strchr(buf,'\r');
+        if (!p) p = strchr(buf,'\n');
+        if (p) *p = '\0';
+        linenoiseHistoryAdd(buf);
+    }
+    fclose(fp);
+    return 0;
+}
diff --git a/src/linenoise/linenoise.h b/src/linenoise/linenoise.h
new file mode 100644
index 000000000..ed20232c5
--- /dev/null
+++ b/src/linenoise/linenoise.h
@@ -0,0 +1,73 @@
+/* linenoise.h -- VERSION 1.0
+ *
+ * Guerrilla line editing library against the idea that a line editing lib
+ * needs to be 20,000 lines of C code.
+ *
+ * See linenoise.c for more information.
+ *
+ * ------------------------------------------------------------------------
+ *
+ * Copyright (c) 2010-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2013, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *  *  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *  *  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __LINENOISE_H
+#define __LINENOISE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct linenoiseCompletions {
+  size_t len;
+  char **cvec;
+} linenoiseCompletions;
+
+typedef void(linenoiseCompletionCallback)(const char *, linenoiseCompletions *);
+typedef char*(linenoiseHintsCallback)(const char *, int *color, int *bold);
+typedef void(linenoiseFreeHintsCallback)(void *);
+void linenoiseSetCompletionCallback(linenoiseCompletionCallback *);
+void linenoiseSetHintsCallback(linenoiseHintsCallback *);
+void linenoiseSetFreeHintsCallback(linenoiseFreeHintsCallback *);
+void linenoiseAddCompletion(linenoiseCompletions *, const char *);
+
+char *linenoise(const char *prompt);
+void linenoiseFree(void *ptr);
+int linenoiseHistoryAdd(const char *line);
+int linenoiseHistorySetMaxLen(int len);
+int linenoiseHistorySave(const char *filename);
+int linenoiseHistoryLoad(const char *filename);
+void linenoiseClearScreen(void);
+void linenoiseSetMultiLine(int ml);
+void linenoisePrintKeyCodes(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __LINENOISE_H */
diff --git a/src/nix/local.mk b/src/nix/local.mk
index e71cf16fa..c7d2d328a 100644
--- a/src/nix/local.mk
+++ b/src/nix/local.mk
@@ -2,12 +2,8 @@ programs += nix
 
 nix_DIR := $(d)
 
-nix_SOURCES := $(wildcard $(d)/*.cc)
+nix_SOURCES := $(wildcard $(d)/*.cc) src/linenoise/linenoise.c
 
 nix_LIBS = libexpr libmain libstore libutil libformat
 
-ifeq ($(HAVE_READLINE), 1)
-  nix_LDFLAGS += -lreadline
-endif
-
 $(eval $(call install-symlink, nix, $(bindir)/nix-hash))
diff --git a/src/nix/repl.cc b/src/nix/repl.cc
index 13488bf1d..437c7903e 100644
--- a/src/nix/repl.cc
+++ b/src/nix/repl.cc
@@ -1,13 +1,8 @@
-#if HAVE_LIBREADLINE
-
 #include <iostream>
 #include <cstdlib>
 
 #include <setjmp.h>
 
-#include <readline/readline.h>
-#include <readline/history.h>
-
 #include "shared.hh"
 #include "eval.hh"
 #include "eval-inline.hh"
@@ -18,6 +13,9 @@
 #include "affinity.hh"
 #include "globals.hh"
 #include "command.hh"
+#include "finally.hh"
+
+#include "src/linenoise/linenoise.h"
 
 namespace nix {
 
@@ -44,14 +42,11 @@ struct NixRepl
 
     const Path historyFile;
 
-    StringSet completions;
-    StringSet::iterator curCompletion;
-
     NixRepl(const Strings & searchPath, nix::ref<Store> store);
     ~NixRepl();
     void mainLoop(const Strings & files);
-    void completePrefix(string prefix);
-    bool getLine(string & input, const char * prompt);
+    StringSet completePrefix(string prefix);
+    bool getLine(string & input, const std::string &prompt);
     Path getDerivationPath(Value & v);
     bool processLine(string line);
     void loadFile(const Path & path);
@@ -122,7 +117,17 @@ NixRepl::NixRepl(const Strings & searchPath, nix::ref<Store> store)
 
 NixRepl::~NixRepl()
 {
-    write_history(historyFile.c_str());
+    linenoiseHistorySave(historyFile.c_str());
+}
+
+
+static NixRepl * curRepl; // ugly
+
+static void completionCallback(const char * s, linenoiseCompletions *lc)
+{
+    /* Otherwise, return all symbols that start with the prefix. */
+    for (auto & c : curRepl->completePrefix(s))
+        linenoiseAddCompletion(lc, c.c_str());
 }
 
 
@@ -137,22 +142,20 @@ void NixRepl::mainLoop(const Strings & files)
     reloadFiles();
     if (!loadedFiles.empty()) std::cout << std::endl;
 
-    // Allow nix-repl specific settings in .inputrc
-    rl_readline_name = "nix-repl";
-    using_history();
     createDirs(dirOf(historyFile));
-    read_history(historyFile.c_str());
+    linenoiseHistorySetMaxLen(1000);
+    linenoiseHistoryLoad(historyFile.c_str());
 
-    string input;
+    curRepl = this;
+    linenoiseSetCompletionCallback(completionCallback);
+
+    std::string input;
 
     while (true) {
         // When continuing input from previous lines, don't print a prompt, just align to the same
         // number of chars as the prompt.
-        const char * prompt = input.empty() ? "nix-repl> " : "          ";
-        if (!getLine(input, prompt)) {
-            std::cout << std::endl;
+        if (!getLine(input, input.empty() ? "nix-repl> " : "          "))
             break;
-        }
 
         try {
             if (!removeWhitespace(input).empty() && !processLine(input)) return;
@@ -170,103 +173,57 @@ void NixRepl::mainLoop(const Strings & files)
             printMsg(lvlError, format(error + "%1%%2%") % (settings.showTrace ? e.prefix() : "") % e.msg());
         }
 
-        // We handled the current input fully, so we should clear it and read brand new input.
+        // We handled the current input fully, so we should clear it
+        // and read brand new input.
+        linenoiseHistoryAdd(input.c_str());
         input.clear();
         std::cout << std::endl;
     }
 }
 
 
-/* Apparently, the only way to get readline() to return on Ctrl-C
-   (SIGINT) is to use siglongjmp().  That's fucked up... */
-static sigjmp_buf sigintJmpBuf;
-
-
-static void sigintHandler(int signo)
+bool NixRepl::getLine(string & input, const std::string &prompt)
 {
-    siglongjmp(sigintJmpBuf, 1);
-}
-
-
-/* Oh, if only g++ had nested functions... */
-NixRepl * curRepl;
-
-char * completerThunk(const char * s, int state)
-{
-    string prefix(s);
-
-    /* If the prefix has a slash in it, use readline's builtin filename
-       completer. */
-    if (prefix.find('/') != string::npos)
-        return rl_filename_completion_function(s, state);
-
-    /* Otherwise, return all symbols that start with the prefix. */
-    if (state == 0) {
-        curRepl->completePrefix(s);
-        curRepl->curCompletion = curRepl->completions.begin();
-    }
-    if (curRepl->curCompletion == curRepl->completions.end()) return 0;
-    return strdup((curRepl->curCompletion++)->c_str());
+    char * s = linenoise(prompt.c_str());
+    Finally doFree([&]() { linenoiseFree(s); });
+    if (!s) return false;
+    input += s;
+    return true;
 }
 
 
-bool NixRepl::getLine(string & input, const char * prompt)
+StringSet NixRepl::completePrefix(string prefix)
 {
-    struct sigaction act, old;
-    act.sa_handler = sigintHandler;
-    sigfillset(&act.sa_mask);
-    act.sa_flags = 0;
-    if (sigaction(SIGINT, &act, &old))
-        throw SysError("installing handler for SIGINT");
-
-    static sigset_t savedSignalMask, set;
-    sigemptyset(&set);
-    sigaddset(&set, SIGINT);
-
-    if (sigprocmask(SIG_UNBLOCK, &set, &savedSignalMask))
-        throw SysError("unblocking SIGINT");
+    StringSet completions;
 
-    if (sigsetjmp(sigintJmpBuf, 1)) {
-        input.clear();
+    size_t start = prefix.find_last_of(" \n\r\t(){}[]");
+    std::string prev, cur;
+    if (start == std::string::npos) {
+        prev = "";
+        cur = prefix;
     } else {
-        curRepl = this;
-        rl_completion_entry_function = completerThunk;
-
-        char * s = readline(prompt);
-        if (!s) return false;
-        input.append(s);
-        input.push_back('\n');
-        if (!removeWhitespace(s).empty()) {
-            add_history(s);
-            append_history(1, 0);
-        }
-        free(s);
+        prev = std::string(prefix, 0, start + 1);
+        cur = std::string(prefix, start + 1);
     }
 
-    _isInterrupted = 0;
-
-    if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr))
-        throw SysError("restoring signals");
-
-    if (sigaction(SIGINT, &old, 0))
-        throw SysError("restoring handler for SIGINT");
-
-    return true;
-}
-
-
-void NixRepl::completePrefix(string prefix)
-{
-    completions.clear();
-
-    size_t dot = prefix.rfind('.');
+    size_t slash, dot;
 
-    if (dot == string::npos) {
+    if ((slash = cur.rfind('/')) != string::npos) {
+        try {
+            auto dir = std::string(cur, 0, slash);
+            auto prefix2 = std::string(cur, slash + 1);
+            for (auto & entry : readDirectory(dir == "" ? "/" : dir)) {
+                if (entry.name[0] != '.' && hasPrefix(entry.name, prefix2))
+                    completions.insert(prev + dir + "/" + entry.name);
+            }
+        } catch (Error &) {
+        }
+    } else if ((dot = cur.rfind('.')) == string::npos) {
         /* This is a variable name; look it up in the current scope. */
-        StringSet::iterator i = varNames.lower_bound(prefix);
+        StringSet::iterator i = varNames.lower_bound(cur);
         while (i != varNames.end()) {
-            if (string(*i, 0, prefix.size()) != prefix) break;
-            completions.insert(*i);
+            if (string(*i, 0, cur.size()) != cur) break;
+            completions.insert(prev + *i);
             i++;
         }
     } else {
@@ -274,8 +231,8 @@ void NixRepl::completePrefix(string prefix)
             /* This is an expression that should evaluate to an
                attribute set.  Evaluate it to get the names of the
                attributes. */
-            string expr(prefix, 0, dot);
-            string prefix2 = string(prefix, dot + 1);
+            string expr(cur, 0, dot);
+            string cur2 = string(cur, dot + 1);
 
             Expr * e = parseString(expr);
             Value v;
@@ -284,8 +241,8 @@ void NixRepl::completePrefix(string prefix)
 
             for (auto & i : *v.attrs) {
                 string name = i.name;
-                if (string(name, 0, prefix2.size()) != prefix2) continue;
-                completions.insert(expr + "." + name);
+                if (string(name, 0, cur2.size()) != cur2) continue;
+                completions.insert(prev + expr + "." + name);
             }
 
         } catch (ParseError & e) {
@@ -296,6 +253,8 @@ void NixRepl::completePrefix(string prefix)
             // Quietly ignore undefined variable errors.
         }
     }
+
+    return completions;
 }
 
 
@@ -728,5 +687,3 @@ struct CmdRepl : StoreCommand
 static RegisterCommand r1(make_ref<CmdRepl>());
 
 }
-
-#endif