Initial import

third_party/editline/ChangeLog.md

@@ -0,0 +1,248 @@
+Change Log
+==========
+
+All notable changes to the project are documented in this file.
+
+
+[1.16.1] - 2019-06-07
+---------------------
+
+### Changes
+- Major updates to the `editline.3` man page
+- Cleanup of examples `cli.c` and `fileman.c`
+- Add example of hidden input prompt to `cli.c`
+
+### Fixes
+- Fix #20: `configure --disable-eof` does not bite
+- Fix #23: Make Ctrl-L clear the screan instead of starting a new line  
+  Like Ctrl-D, which exits, Ctrl-L only clears the screen when the line
+  is empty and the cursor is at the start of the line, otherwise Ctrl-L
+  will redraw/refresh the current line.
+- Fix #24: Fix behavior when TTY is narrower than column width, by Will Dietz
+- Fix #25: Avoid continuously duplicate commands in history
+- Fix #31: Aborting i-search with Ctrl-C should not generate signal
+
+
+[1.16.0][] - 2018-09-16
+-----------------------
+
+Event loop callback support.
+
+### Changes
+- `rl_unintialize()`, new function to free all memory, by Claus Fischer
+- `rl_insert_text()`, new GNU Readline compat function
+- `rl_refresh_line()`, new GNU Readline compat function
+- `rl_callback_*()`, alternate interface to plain `readline()` for event
+  loops.  Modeled after the GNU Readline API
+- `rl_completion_entry_function`, and `rl_attempted_completion_function`
+  are two new GNU Readline compat user hooks for the completion framework
+- `rl_completion_matches()` and `rl_filename_completion_function()`
+  are two new GNU Readline compat functions
+- Add new example: `fileman.c` from GNU Readline to demonstrate the
+  level of compatibility of the revamped completion framework
+- Add support for Ctrl-Right and Ctrl-Left, forward/backward word
+- Add .deb package to official release target
+
+### Fixes
+- Fixed header guards, avoid using leading `__`
+- Spell check fixes
+- Remove duplicate code in history check
+- Use `NULL` instead of `0`, and `-1` instead of `NULL`, where applicable
+- Misc. minor Coverity Scan fixes
+- Misc. minor fixes to `testit.c` example code
+- Add `-Wextra` to std `CFLAGS`
+- Check `fclose()` return value in in `write_history()` and `read_history()`
+- Initialize global variables and reset to `NULL` on `free()`
+- Fix off-by-one in forward kill word, avoid deleting too much
+- Skip (or kill) leading whitespace when skipping (or killing) forwards
+
+
+[1.15.3][] - 2017-09-07
+-----------------------
+
+Bug fix release.
+
+### Changes
+- Refactor all enable/disable configure options, same problem as in #7
+
+### Fixes
+- Fix #7: `--enable-termcap` configure option does not work.  The script
+  enabled termcap by default rather than the other way around.
+  
+  Also, check for terminfo as well, when `--enable-termcap` is selected.
+
+
+[1.15.2][] - 2016-06-06
+-----------------------
+
+Bug fixes and minor feature creep in `pkg-config` support.
+
+### Changes
+- Prevent mangling of symbols when linking with C++.  Patch courtesy of
+  Jakub Pawlowski
+- Add `libeditline.pc` for `pkg-config`
+
+### Fixes
+- Do not assume a termcap library exists, check for `tgetent()` in
+  curses, ncurses, tinfo and termcap libraries
+- Call `tty_flush()` when user calls `rl_forced_update_display()`
+  to prevent screen becoming garbled.  Patch by Jakub Pawlowski
+
+
+[1.15.1][] - 2015-11-16
+-----------------------
+
+Bug fixes only.
+
+### Changes
+- Update README with origin of this version of editline
+
+### Fixes
+- Fix build system, don't force automake v1.11, require at least v1.11
+- Fix build problem with examples using `--enable-termcap`
+
+
+[1.15.0][] - 2015-09-10
+-----------------------
+
+### Changes
+- Add support for `--disable-eof` and `--disable-sigint` to disable
+  default Ctrl-D and Ctrl-C behavior
+- Add support for `el_no_hist` to disable access to and auto-save of history
+- GNU readline compat functions for prompt handling and redisplay
+- Refactor: replace variables named 'new' with non-reserved word
+- Add support for [Travis-CI][], continuous integration with GitHub
+- Add support for [Coverity Scan][], the best static code analyzer,
+  integrated with [Travis-CI][] -- scan runs for each push to master
+- Rename NEWS.md --> ChangeLog.md, with symlinks for <kbd>make install</kbd>
+- Attempt to align with http://keepachangelog.com/ for this file
+- Cleanup and improve Markdown syntax in [README.md][]
+- Add API and example to [README.md][], inspired by [libuEv][]
+- Removed generated files from version control.  Use `./autogen.sh`
+  to generate the `configure` script when working from GIT.  This
+  does not affect distributed tarballs
+
+### Fixes
+- Fix issue #2, regression in Ctrl-D (EOF) behavior.  Regression
+  introduced in [1.14.1][].  Fixed by @TobyGoodwin
+- Fix memory leak in completion handler.  Found by [Coverity Scan][].
+- Fix suspicious use of `sizeof(char **)`, same as `sizeof(char *)` but
+  non-portable.  Found by [Coverity Scan][]
+- Fix out-of-bounds access in user key binding routines
+  Found by [Coverity Scan][].
+- Fix invisible example code in man page
+
+
+[1.14.2][] - 2014-09-14
+-----------------------
+
+Bug fixes only.
+
+### Fixes
+  - Fix `el_no_echo` bug causing secrets to leak when disabling no-echo
+  - Handle `EINTR` in syscalls better
+
+
+[1.14.1][] - 2014-09-14
+-----------------------
+
+Minor fixes and additions.
+
+### Changes
+- Don't print status message on `stderr` in key binding funcions
+- Export `el_del_char()`
+- Check for and return pending signals when detected
+- Allow custom key bindings ...
+
+### Fixes
+- Bug fixes ...
+
+
+[1.14.0][] - 2010-08-10
+-----------------------
+
+Major cleanups and further merges with Debian editline package.
+
+### Changes
+- Merge in changes to `debian/` from `editline_1.12-6.debian.tar.gz`
+- Migrate to use libtool
+- Make `UNIQUE_HISTORY` configurable
+- Make scrollback history (`HIST_SIZE`) configurable
+- Configure options for toggling terminal bell and `SIGSTOP` (Ctrl-Z)
+- Configure option for using termcap to read/control terminal size
+- Rename Signal to `el_intr_pending`, from Festival speech-tools
+- Merge support for capitalizing words (`M-c`) from Festival
+  speech-tools by Alan W Black <mailto:awb()cstr!ed!ac!uk>
+- Fallback backspace handling, in case `tgetstr("le")` fails
+
+### Fixes
+- Cleanups and fixes thanks to the Sparse static code analysis tool
+- Merge `el_no_echo` patch from Festival speech-tools
+- Merge fixes from Heimdal project
+- Completely refactor `rl_complete()` and `rl_list_possib()` with
+  fixes from the Heimdal project.  Use `rl_set_complete_func()` and
+  `rl_set_list_possib_func()`.  Default completion callbacks are now
+  available as a configure option `--enable-default-complete`
+- Memory leak fixes
+- Actually fix 8-bit handling by reverting old Debian patch
+- Merge patch to improve compatibility with GNU readline, thanks to
+  Steve Tell from way back in 1997 and 1998
+
+
+[1.13.0][] - 2010-03-09
+-----------------------
+
+Adaptations to Debian editline package.
+
+### Changes
+- Major version number bump, adapt to Jim Studt's v1.12
+- Import `debian/` directory and adapt it to configure et al.
+- Change library name to libeditline to distinguish it from BSD libedit
+
+
+[0.3.0][] - 2009-02-08
+----------------------
+
+### Changes
+- Support for ANSI arrow keys using <kbd>configure --enable-arrow-keys</kbd>
+
+
+[0.2.3][] - 2008-12-02
+----------------------
+
+### Changes
+- Patches from Debian package merged
+- Support for custom command completion
+
+
+[0.1.0][] - 2008-06-07
+----------------------
+
+### Changes
+- First version, forked from Minix current 2008-06-06
+
+
+[UNRELEASED]:    https://github.com/troglobit/finit/compare/1.16.0...HEAD
+[1.16.1]:        https://github.com/troglobit/finit/compare/1.16.0...1.16.1
+[1.16.0]:        https://github.com/troglobit/finit/compare/1.15.3...1.16.0
+[1.15.3]:        https://github.com/troglobit/finit/compare/1.15.2...1.15.3
+[1.15.2]:        https://github.com/troglobit/finit/compare/1.15.1...1.15.2
+[1.15.1]:        https://github.com/troglobit/finit/compare/1.15.0...1.15.1
+[1.15.0]:        https://github.com/troglobit/finit/compare/1.14.2...1.15.0
+[1.14.2]:        https://github.com/troglobit/finit/compare/1.14.1...1.14.2
+[1.14.1]:        https://github.com/troglobit/finit/compare/1.14.0...1.14.1
+[1.14.0]:        https://github.com/troglobit/finit/compare/1.13.0...1.14.0
+[1.13.0]:        https://github.com/troglobit/finit/compare/0.3.0...1.13.0
+[0.3.0]:         https://github.com/troglobit/finit/compare/0.2.3...0.3.0
+[0.2.3]:         https://github.com/troglobit/finit/compare/0.1.0...0.2.3
+[0.1.0]:         https://github.com/troglobit/finit/compare/0.0.0...0.1.0
+[libuEv]:        http://github.com/troglobit/libuev
+[Travis-CI]:     https://travis-ci.org/troglobit/uftpd
+[Coverity Scan]: https://scan.coverity.com/projects/2947
+[README.md]:     https://github.com/troglobit/editline/blob/master/README.md
+
+<!--
+  -- Local Variables:
+  -- mode: markdown
+  -- End:
+  -->

third_party/editline/LICENSE

@@ -0,0 +1,18 @@
+ Copyright 1992,1993 Simmule Turner and Rich Salz
+ All rights reserved.
+
+ This software is not subject to any license of the American Telephone
+ and Telegraph Company or of the Regents of the University of California.
+
+ Permission is granted to anyone to use this software for any purpose on
+ any computer system, and to alter it and redistribute it freely, subject
+ to the following restrictions:
+ 1. The authors are not responsible for the consequences of use of this
+    software, no matter how awful, even if they arise from flaws in it.
+ 2. The origin of this software must not be misrepresented, either by
+    explicit claim or by omission.  Since few users ever read sources,
+    credits must appear in the documentation.
+ 3. Altered versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.  Since few users
+    ever read sources, credits must appear in the documentation.
+ 4. This notice may not be removed or altered.

third_party/editline/complete.c

@@ -0,0 +1,362 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ This program is free software; you can redistribute it and/or modify         │
+│ it under the terms of the GNU General Public License as published by         │
+│ the Free Software Foundation; version 2 of the License.                      │
+│                                                                              │
+│ This program is distributed in the hope that it will be useful, but          │
+│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
+│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
+│ General Public License for more details.                                     │
+│                                                                              │
+│ You should have received a copy of the GNU General Public License            │
+│ along with this program; if not, write to the Free Software                  │
+│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
+│ 02110-1301 USA                                                               │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/alg/alg.h"
+#include "libc/calls/calls.h"
+#include "libc/calls/struct/dirent.h"
+#include "libc/fmt/fmt.h"
+#include "libc/mem/mem.h"
+#include "libc/str/str.h"
+#include "third_party/editline/editline.h"
+#include "third_party/editline/internal.h"
+
+asm(".ident\t\"\\n\\n\
+Cosmopolitan Linenoise (BSD-like license)\\n\
+Copyright 2019 Justine Alexandra Roberts Tunney\\n\
+Copyright 1992,1993 Simmule Turner and Rich Salz\\n\
+All rights reserved.\\n\
+\\n\
+This software is not subject to any license of the American Telephone\\n\
+and Telegraph Company or of the Regents of the University of California.\\n\
+\\n\
+Permission is granted to anyone to use this software for any purpose on\\n\
+any computer system, and to alter it and redistribute it freely, subject\\n\
+to the following restrictions:\\n\
+1. The authors are not responsible for the consequences of use of this\\n\
+   software, no matter how awful, even if they arise from flaws in it.\\n\
+2. The origin of this software must not be misrepresented, either by\\n\
+   explicit claim or by omission.  Since few users ever read sources,\\n\
+   credits must appear in the documentation.\\n\
+3. Altered versions must be plainly marked as such, and must not be\\n\
+   misrepresented as being the original software.  Since few users\\n\
+   ever read sources, credits must appear in the documentation.\\n\
+4. This notice may not be removed or altered.\"");
+asm(".include \"libc/disclaimer.inc\"");
+
+#define MAX_TOTAL_MATCHES (256 << sizeof(char *))
+
+int rl_attempted_completion_over = 0;
+rl_completion_func_t *rl_attempted_completion_function = NULL;
+rl_compentry_func_t *rl_completion_entry_function = NULL;
+
+/* Wrap strcmp() for qsort() -- weird construct to pass -Wcast-qual */
+static int compare(const void *p1, const void *p2) {
+  char *const *v1 = (char *const *)p1;
+  char *const *v2 = (char *const *)p2;
+  return strcmp(*v1, *v2);
+}
+
+/* Fill in *avp with an array of names that match file, up to its length.
+ * Ignore . and .. . */
+static int FindMatches(char *dir, char *file, char ***avp) {
+  char **av;
+  char **word;
+  char *p;
+  DIR *dp;
+  struct dirent *ep;
+  size_t ac;
+  size_t len;
+  size_t choices;
+  size_t total;
+  if ((dp = opendir(dir)) == NULL) return 0;
+  av = NULL;
+  ac = 0;
+  len = strlen(file);
+  choices = 0;
+  total = 0;
+  while ((ep = readdir(dp)) != NULL) {
+    p = ep->d_name;
+    if (p[0] == '.' && (p[1] == '\0' || (p[1] == '.' && p[2] == '\0')))
+      continue;
+    if (len && strncmp(p, file, len) != 0) continue;
+    choices++;
+    if ((total += strlen(p)) > MAX_TOTAL_MATCHES) {
+      /* This is a bit too much. */
+      while (ac > 0) free(av[--ac]);
+      continue;
+    }
+    if ((ac % MEM_INC) == 0) {
+      word = malloc(sizeof(char *) * (ac + MEM_INC));
+      if (!word) {
+        total = 0;
+        break;
+      }
+      if (ac) {
+        memcpy(word, av, ac * sizeof(char *));
+        free(av);
+      }
+      *avp = av = word;
+    }
+    if ((av[ac] = strdup(p)) == NULL) {
+      if (ac == 0) free(av);
+      total = 0;
+      break;
+    }
+    ac++;
+  }
+  /* Clean up and return. */
+  closedir(dp);
+  if (total > MAX_TOTAL_MATCHES) {
+    char many[sizeof(total) * 3];
+    p = many + sizeof(many);
+    *--p = '\0';
+    while (choices > 0) {
+      *--p = '0' + choices % 10;
+      choices /= 10;
+    }
+    while (p > many + sizeof(many) - 8) *--p = ' ';
+    if ((p = strdup(p)) != NULL) av[ac++] = p;
+    if ((p = strdup("choices")) != NULL) av[ac++] = p;
+  } else {
+    if (ac) qsort(av, ac, sizeof(char *), compare);
+  }
+  return ac;
+}
+
+/* Split a pathname into allocated directory and trailing filename parts. */
+static int SplitPath(const char *path, char **dirpart, char **filepart) {
+  static char DOT[] = ".";
+  char *dpart;
+  char *fpart;
+  if ((fpart = strrchr(path, '/')) == NULL) {
+    if ((dpart = strdup(DOT)) == NULL) return -1;
+    if ((fpart = strdup(path)) == NULL) {
+      free(dpart);
+      return -1;
+    }
+  } else {
+    if ((dpart = strdup(path)) == NULL) return -1;
+    dpart[fpart - path + 1] = '\0';
+    if ((fpart = strdup(fpart + 1)) == NULL) {
+      free(dpart);
+      return -1;
+    }
+  }
+  *dirpart = dpart;
+  *filepart = fpart;
+  return 0;
+}
+
+static rl_complete_func_t *el_complete_func = NULL;
+
+/* For compatibility with the Heimdal project. */
+rl_complete_func_t *rl_set_complete_func(rl_complete_func_t *func) {
+  rl_complete_func_t *old = el_complete_func;
+  el_complete_func = func;
+  return old;
+}
+
+/* Attempt to complete the pathname, returning an allocated copy.
+ * Fill in *match if we completed it, or set it to 0 if ambiguous. */
+char *el_filename_complete(char *pathname, int *match) {
+  char **av;
+  char *dir;
+  char *file;
+  char *path;
+  char *p;
+  size_t ac;
+  size_t end;
+  size_t i;
+  size_t j;
+  size_t len;
+  if (SplitPath((const char *)pathname, &dir, &file) < 0) return NULL;
+  if ((ac = FindMatches(dir, file, &av)) == 0) {
+    free(dir);
+    free(file);
+    return NULL;
+  }
+  p = NULL;
+  len = strlen(file);
+  if (ac == 1) {
+    /* Exactly one match -- finish it off. */
+    *match = 1;
+    j = strlen(av[0]) - len + 2;
+    p = malloc(sizeof(char) * (j + 1));
+    if (p) {
+      memcpy(p, av[0] + len, j);
+      len = strlen(dir) + strlen(av[0]) + 2;
+      path = malloc(sizeof(char) * len);
+      if (path) {
+        snprintf(path, len, "%s/%s", dir, av[0]);
+        rl_add_slash(path, p);
+        free(path);
+      }
+    }
+  } else {
+    *match = 0;
+    if (len) {
+      /* Find largest matching substring. */
+      for (i = len, end = strlen(av[0]); i < end; i++) {
+        for (j = 1; j < ac; j++) {
+          if (av[0][i] != av[j][i]) goto breakout;
+        }
+      }
+    breakout:
+      if (i > len) {
+        j = i - len + 1;
+        p = malloc(sizeof(char) * j);
+        if (p) {
+          memcpy(p, av[0] + len, j);
+          p[j - 1] = '\0';
+        }
+      }
+    }
+  }
+  /* Clean up and return. */
+  free(dir);
+  free(file);
+  for (i = 0; i < ac; i++) free(av[i]);
+  free(av);
+  return p;
+}
+
+char *rl_filename_completion_function(const char *text, int state) {
+  char *dir;
+  char *file;
+  static char **av;
+  static size_t i, ac;
+  if (!state) {
+    if (SplitPath(text, &dir, &file) < 0) return NULL;
+    ac = FindMatches(dir, file, &av);
+    free(dir);
+    free(file);
+    if (!ac) return NULL;
+    i = 0;
+  }
+  if (i < ac) return av[i++];
+  do {
+    free(av[--i]);
+  } while (i > 0);
+  return NULL;
+}
+
+/* Similar to el_find_word(), but used by GNU Readline API */
+static char *rl_find_token(size_t *len) {
+  char *ptr;
+  int pos;
+  for (pos = rl_point; pos < rl_end; pos++) {
+    if (isspace(rl_line_buffer[pos])) {
+      if (pos > 0) pos--;
+      break;
+    }
+  }
+  ptr = &rl_line_buffer[pos];
+  while (pos >= 0 && !isspace(rl_line_buffer[pos])) {
+    if (pos == 0) break;
+    pos--;
+  }
+  if (ptr != &rl_line_buffer[pos]) {
+    *len = (size_t)(ptr - &rl_line_buffer[pos]);
+    return &rl_line_buffer[pos];
+  }
+  return NULL;
+}
+
+/*
+ * "uses an application-supplied generator function to generate the list
+ * of possible matches, and then returns the array of these matches. The
+ * caller should place the address of its generator function in
+ * rl_completion_entry_function"
+ */
+char **rl_completion_matches(const char *token,
+                             rl_compentry_func_t *generator) {
+  int state = 0, num = 0;
+  char **array, *entry;
+  if (!generator) {
+    generator = rl_completion_entry_function;
+    if (!generator) generator = rl_filename_completion_function;
+  }
+  if (!generator) return NULL;
+  array = malloc(512 * sizeof(char *));
+  if (!array) return NULL;
+  while (num < 511 && (entry = generator(token, state))) {
+    state = 1;
+    array[num++] = entry;
+  }
+  array[num] = NULL;
+  if (!num) {
+    free(array);
+    return NULL;
+  }
+  return array;
+}
+
+static char *complete(char *token, int *match) {
+  size_t len = 0;
+  char *word, **words = NULL;
+  int start, end;
+  word = rl_find_token(&len);
+  if (!word) goto fallback;
+  start = word - rl_line_buffer;
+  end = start + len;
+  word = strndup(word, len);
+  if (!word) goto fallback;
+  rl_attempted_completion_over = 0;
+  words = rl_attempted_completion_function(word, start, end);
+  if (!rl_attempted_completion_over && !words)
+    words = rl_completion_matches(word, NULL);
+  if (words) {
+    int i = 0;
+    free(word);
+    word = NULL;
+    if (words[0]) word = strdup(words[0] + len);
+    while (words[i]) free(words[i++]);
+    free(words);
+    if (word) return word;
+  }
+fallback:
+  return el_filename_complete(token, match);
+}
+
+/*
+ * First check for editline specific custom completion function, then
+ * for any GNU Readline compat, then fallback to filename completion.
+ */
+char *rl_complete(char *token, int *match) {
+  if (el_complete_func) return el_complete_func(token, match);
+  if (rl_attempted_completion_function) return complete(token, match);
+  return el_filename_complete(token, match);
+}
+
+static rl_list_possib_func_t *el_list_possib_func = NULL;
+
+/* For compatibility with the Heimdal project. */
+rl_list_possib_func_t *rl_set_list_possib_func(rl_list_possib_func_t *func) {
+  rl_list_possib_func_t *old = el_list_possib_func;
+  el_list_possib_func = func;
+  return old;
+}
+
+/* Default possible completions. */
+int el_filename_list_possib(char *pathname, char ***av) {
+  char *dir;
+  char *file;
+  int ac;
+  if (SplitPath(pathname, &dir, &file) < 0) return 0;
+  ac = FindMatches(dir, file, av);
+  free(dir);
+  free(file);
+  return ac;
+}
+
+/* Return all possible completions. */
+int rl_list_possib(char *token, char ***av) {
+  if (el_list_possib_func) return el_list_possib_func(token, av);
+  return el_filename_list_possib(token, av);
+}

third_party/editline/editline.3

@@ -0,0 +1,274 @@
+.Dd April 27, 2019
+.Dt "THIRD_PARTY_EDITLINE" 30 "Cosmopolitan Field Manual"
+.Os COSMOPOLITAN
+.Sh NAME
+.Nm "THIRD_PARTY_EDITLINE"
+.Nd command-line editing library with history
+.Sh SYNOPSIS
+.Pp
+.Sy #include "third_party/editline/editline.h"
+.Pp
+.Fn "char *readline" "const char *prompt"
+.Fn "void add_history"  "const char *line"
+.Fn "int read_history"  "const char *filename"
+.Fn "int write_history" "const char *filename"
+.Sh DESCRIPTION
+.Nm
+is a library that provides n line-editing interface with history.  It
+is intended to be functionally equivalent with the
+.Nm readline
+library provided by the Free Software Foundation, but much smaller.  The
+bulk of this manual page describes the basic user interface.  More APIs,
+both native and for
+.Nm readline
+compatibility ,
+are also available.  See the
+.Cm editline.h
+header file for details.
+.Pp
+The
+.Fn readline
+function displays the given
+.Fa prompt
+on stdout, waits for user input on stdin and then returns a line of text
+with the trailing newline removed.  The data is returned in a buffer
+allocated with
+.Xr malloc 3 ,
+so the space should be released with
+.Xr free 3
+when the calling program is done with it.
+.Pp
+Each line returned is automatically saved in the internal history list,
+unless it happens to be equal to the previous line.  This is
+configurable if you are building editline from source, i.e. if you would
+rather like to call
+.Fn add_history
+manually.
+.Pp
+The
+.Fn read_history
+and
+.Fn write_history
+functions can be used to load and store the history of your application.
+.Em Note:
+these APIs do not do any tilde or environment variable expansion of the
+given filename.
+.Ss User Interface
+A program that uses this library provides a simple emacs-like editing
+interface to its users.  A line may be edited before it is sent to the
+calling program by typing either control characters or escape sequences.
+A control character, shown as a caret followed by a letter, is typed by
+holding down the control key while the letter is typed.  For example,
+.Cm ^A
+is a control-A.  An escape sequence is entered by typing the escape key
+followed by one or more characters.  The escape key is abbreviated as
+.Cm ESC .
+Note that unlike control keys, case matters in escape sequences;
+.Cm ESC F
+is not the same as
+.Cm ESC f .
+.Pp
+An editing command may be typed anywhere on the line, not just at the
+beginning.  In addition, a return may also be typed anywhere on the
+line, not just at the end.
+.Pp
+Most editing commands may be given a repeat count,
+.Ar n ,
+where
+.Ar n
+is a number.  To enter a repeat count, type the escape key, the number,
+and then the command to execute.  For example,
+.Cm ESC 4 ^f
+moves forward four characters.  If a command may be given a repeat count
+then the text
+.Cm [n]
+is given at the end of its description.
+.Pp
+The following control characters are accepted:
+.Pp
+.Bl -tag -width "ESC DEL " -compact
+.It ^A
+Move to the beginning of the line
+.It ^B
+Move left (backwards) [n]
+.It ^D
+Delete character [n]
+.It ^E
+Move to end of line
+.It ^F
+Move right (forwards) [n]
+.It ^G
+Ring the bell
+.It ^H
+Delete character before cursor (backspace key) [n]
+.It ^I
+Complete filename (tab key); see below
+.It ^J
+Done with line (return key)
+.It ^K
+Kill to end of line (or column [n])
+.It ^L
+Redisplay line
+.It ^M
+Done with line (alternate return key)
+.It ^N
+Get next line from history [n]
+.It ^P
+Get previous line from history [n]
+.It ^R
+Search backward (forward if [n]) through history for text; prefixing the
+string with a caret (^) forces it to match only at the beginning of a
+history line
+.It ^T
+Transpose characters
+.It ^V
+Insert next character, even if it is an edit command
+.It ^W
+Wipe to the mark
+.It ^X^X
+Exchange current location and mark
+.It ^Y
+Yank back last killed text
+.It ^[
+Start an escape sequence (escape key)
+.It ^]c
+Move forward to next character
+.Cm c
+.It ^?
+Delete character before cursor (delete key) [n]
+.Ed
+.Pp
+The following escape sequences are provided:
+.Pp
+.Bl -tag -width "ESC DEL " -compact
+.It ESC ^H
+Delete previous word (backspace key) [n]
+.It ESC DEL
+Delete previous word (delete key) [n]
+.It ESC SP
+Set the mark (space key); see ^X^X and ^Y above
+.It ESC\ .
+Get the last (or [n]'th) word from previous line
+.It ESC\ ?
+Show possible completions; see below
+.It ESC <
+Move to start of history
+.It ESC >
+Move to end of history
+.It ESC b
+Move backward a word [n]
+.It ESC d
+Delete word under cursor [n]
+.It ESC f
+Move forward a word [n]
+.It ESC l
+Make word lowercase [n]
+.It ESC m
+Toggle if 8bit chars display normally or with an
+.Ar M-
+prefix
+.It ESC u
+Make word uppercase [n]
+.It ESC y
+Yank back last killed text
+.It ESC v
+Show library version
+.It ESC w
+Make area up to mark yankable
+.It ESC nn
+Set repeat count to the number nn
+.It ESC C
+Read from environment variable
+.Ar $C ,
+where
+.Ar C
+is an uppercase letter
+.El
+.Pp
+The
+.Nm
+library has a small macro facility.  If you type the escape key followed
+by an uppercase letter,
+.Ar C ,
+then the contents of the environment variable
+.Ar $C
+are read in as if you had typed them at the keyboard.  For example, if
+the variable
+.Ar $L
+contains the following:
+.Pp
+.Dl ^A^Kecho '^V^[[H^V^[[2J'^M
+.Pp
+Then typing
+.Cm ESC L
+will move to the beginning of the line, kill the entire line, enter the
+echo command needed to clear the terminal (if your terminal is like a
+VT-100), and send the line back to the shell.
+.Pp
+The
+.Nm
+library also does filename completion.  Suppose the root directory has
+the following files in it:
+.Pp
+.Dl bin	vmunix
+.Dl core	vmunix.old
+.Pp
+If you type
+.Cm rm /v
+and then the tab key,
+.Nm
+will then finish off as much of the name as possible by adding
+.Ar munix .
+Because the name is not unique, it will then beep.  If you type the
+escape key and a question mark, it will display the two choices.  If you
+then type a period and a tab, the library will finish off the filename
+for you:
+.Pp
+.Bd -ragged -offset indent
+rm /v[TAB]
+.Em munix
+\&.[TAB]
+.Em old
+.Ed
+.Pp
+The tab key is shown by [TAB] and the automatically-entered text
+is shown in italics, or underline.
+.Sh USAGE
+To include
+.Nm
+in your program, call it as you do any other function and link your
+program with
+.Ar -leditline .
+.Ss Example
+The following brief example lets you enter a line and edit it, then displays it.
+.Pp
+.Bd -literal -offset indent
+#include <stdio.h>
+#include <stdlib.h>
+#include <editline.h>
+
+int main(void)
+{
+	char *p;
+
+	while ((p = readline("CLI> "))) {
+	        puts(p);
+	        free(p);
+	}
+
+	return 0;
+}
+.El
+.Sh AUTHORS
+The original editline library was posted to comp.sources.unix newsgroup
+by created by Simmule R. Turner and Rich Salz in 1992.  It now exists in
+several forks: Debian, Minix, Heimdal, Festival speech tools, Mozilla,
+Google Gadgets for Linux, and many other places.  The original manual
+page was made by David W. Sanderson.
+.Pp
+This version was originally based on the Minix 2 sources, but has since
+evolved to include patches from all relevant forks.  It is currently
+maintained by Joachim Nilsson at GitHub,
+.Aq http://github.com/troglobit/editline
+.Sh BUGS
+Does not handle multiple lines well.

third_party/editline/editline.h

@@ -0,0 +1,91 @@
+#ifndef COSMOPOLITAN_THIRD_PARTY_EDITLINE_EDITLINE_H_
+#define COSMOPOLITAN_THIRD_PARTY_EDITLINE_EDITLINE_H_
+#include "libc/stdio/stdio.h"
+
+#define CTL(x)    ((x)&0x1F)
+#define ISCTL(x)  ((x) && (x) < ' ')
+#define UNCTL(x)  ((x) + 64)
+#define META(x)   ((x) | 0x80)
+#define ISMETA(x) ((x)&0x80)
+#define UNMETA(x) ((x)&0x7F)
+
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+typedef enum {
+  CSdone = 0, /* OK */
+  CSeof,      /* Error, or EOF */
+  CSmove,
+  CSdispatch,
+  CSstay,
+  CSsignal
+} el_status_t;
+
+typedef int rl_list_possib_func_t(char *, char ***);
+typedef el_status_t el_keymap_func_t(void);
+typedef int rl_hook_func_t(void);
+typedef int rl_getc_func_t(void);
+typedef void rl_voidfunc_t(void);
+typedef void rl_vintfunc_t(int);
+typedef void rl_vcpfunc_t(char *);
+compatfn typedef char *rl_complete_func_t(char *, int *);
+compatfn typedef char *rl_compentry_func_t(const char *, int);
+compatfn typedef char **rl_completion_func_t(const char *, int, int);
+
+extern int rl_point;
+extern int rl_mark;
+extern int rl_end;
+extern int rl_inhibit_complete;
+extern char *rl_line_buffer;
+extern const char *rl_readline_name;
+extern FILE *rl_instream; /* The stdio stream from which input is read. Defaults
+                             to stdin if NULL - Not supported yet! */
+extern FILE *rl_outstream; /* The stdio stream to which output is flushed.
+                              Defaults to stdout if NULL - Not supported yet! */
+extern int el_no_echo;     /* E.g under emacs, don't echo except prompt */
+extern int el_no_hist; /* Disable auto-save of and access to history -- e.g. for
+                          password prompts or wizards */
+extern int el_hist_size;  /* size of history scrollback buffer, default: 15 */
+extern int rl_meta_chars; /* Display 8-bit chars "as-is" or as `M-x'? Toggle
+                             with M-m. (Default:0 - "as-is") */
+extern rl_completion_func_t *rl_attempted_completion_function;
+
+char **rl_completion_matches(const char *, rl_compentry_func_t *);
+char *el_find_word(void);
+char *readline(const char *);
+char *rl_complete(char *, int *);
+char *rl_filename_completion_function(const char *, int);
+const char *el_next_hist(void);
+const char *el_prev_hist(void);
+el_status_t el_bind_key(int, el_keymap_func_t);
+el_status_t el_bind_key_in_metamap(int, el_keymap_func_t);
+el_status_t el_del_char(void);
+el_status_t el_ring_bell(void);
+int read_history(const char *);
+int rl_getc(void);
+int rl_insert_text(const char *);
+int rl_list_possib(char *, char ***);
+int rl_refresh_line(int, int);
+int write_history(const char *);
+rl_complete_func_t *rl_set_complete_func(rl_complete_func_t *);
+rl_getc_func_t *rl_set_getc_func(rl_getc_func_t *);
+rl_list_possib_func_t *rl_set_list_possib_func(rl_list_possib_func_t *);
+void add_history(const char *);
+void el_print_columns(int, char **);
+void rl_callback_handler_install(const char *, rl_vcpfunc_t *);
+void rl_callback_handler_remove(void);
+void rl_callback_read_char(void);
+void rl_clear_message(void);
+void rl_deprep_terminal(void);
+void rl_forced_update_display(void);
+void rl_initialize(void);
+void rl_prep_terminal(int);
+void rl_reset_terminal(const char *);
+void rl_restore_prompt(void);
+void rl_save_prompt(void);
+void rl_set_prompt(const char *);
+void rl_uninitialize(void);
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_THIRD_PARTY_EDITLINE_EDITLINE_H_ */

third_party/editline/editline.mk

@@ -0,0 +1,57 @@
+#-*-mode:makefile-gmake;indent-tabs-mode:t;tab-width:8;coding:utf-8-*-┐
+#───vi: set et ft=make ts=8 tw=8 fenc=utf-8 :vi───────────────────────┘
+
+PKGS += THIRD_PARTY_EDITLINE
+
+THIRD_PARTY_EDITLINE_ARTIFACTS += THIRD_PARTY_EDITLINE_A
+THIRD_PARTY_EDITLINE = $(THIRD_PARTY_EDITLINE_A_DEPS) $(THIRD_PARTY_EDITLINE_A)
+THIRD_PARTY_EDITLINE_A = o/$(MODE)/third_party/editline/editline.a
+THIRD_PARTY_EDITLINE_A_FILES := $(wildcard third_party/editline/*)
+THIRD_PARTY_EDITLINE_A_HDRS = $(filter %.h,$(THIRD_PARTY_EDITLINE_A_FILES))
+THIRD_PARTY_EDITLINE_A_SRCS = $(filter %.c,$(THIRD_PARTY_EDITLINE_A_FILES))
+
+THIRD_PARTY_EDITLINE_A_OBJS =					\
+	$(THIRD_PARTY_EDITLINE_A_SRCS:%=o/$(MODE)/%.zip.o)	\
+	$(THIRD_PARTY_EDITLINE_A_SRCS:%.c=o/$(MODE)/%.o)
+
+THIRD_PARTY_EDITLINE_A_CHECKS =					\
+	$(THIRD_PARTY_EDITLINE_A).pkg
+
+THIRD_PARTY_EDITLINE_A_DIRECTDEPS =				\
+	LIBC_ALG						\
+	LIBC_CALLS						\
+	LIBC_CALLS_HEFTY					\
+	LIBC_FMT						\
+	LIBC_LOG						\
+	LIBC_MEM						\
+	LIBC_NEXGEN32E						\
+	LIBC_STDIO						\
+	LIBC_STR						\
+	LIBC_STUBS						\
+	LIBC_SYSV
+
+THIRD_PARTY_EDITLINE_A_DEPS :=					\
+	$(call uniq,$(foreach x,$(THIRD_PARTY_EDITLINE_A_DIRECTDEPS),$($(x))))
+
+$(THIRD_PARTY_EDITLINE_A):					\
+		third_party/editline/				\
+		$(THIRD_PARTY_EDITLINE_A).pkg			\
+		$(THIRD_PARTY_EDITLINE_A_OBJS)
+
+$(THIRD_PARTY_EDITLINE_A).pkg:					\
+		$(THIRD_PARTY_EDITLINE_A_OBJS)			\
+		$(foreach x,$(THIRD_PARTY_EDITLINE_A_DIRECTDEPS),$($(x)_A).pkg)
+
+THIRD_PARTY_EDITLINE_LIBS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)))
+THIRD_PARTY_EDITLINE_SRCS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)_SRCS))
+THIRD_PARTY_EDITLINE_HDRS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)_HDRS))
+THIRD_PARTY_EDITLINE_BINS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)_BINS))
+THIRD_PARTY_EDITLINE_CHECKS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)_CHECKS))
+THIRD_PARTY_EDITLINE_OBJS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)_OBJS))
+THIRD_PARTY_EDITLINE_TESTS = $(foreach x,$(THIRD_PARTY_EDITLINE_ARTIFACTS),$($(x)_TESTS))
+$(THIRD_PARTY_EDITLINE_OBJS): $(BUILD_FILES) third_party/editline/editline.mk
+
+.PHONY: o/$(MODE)/third_party/editline
+o/$(MODE)/third_party/editline:					\
+		$(THIRD_PARTY_EDITLINE)				\
+		$(THIRD_PARTY_EDITLINE_CHECKS)

third_party/editline/internal.h

@@ -0,0 +1,21 @@
+#ifndef COSMOPOLITAN_THIRD_PARTY_EDITLINE_INTERNAL_H_
+#define COSMOPOLITAN_THIRD_PARTY_EDITLINE_INTERNAL_H_
+#if !(__ASSEMBLER__ + __LINKER__ + 0)
+COSMOPOLITAN_C_START_
+
+#define MEM_INC    64
+#define SCREEN_INC 256
+
+extern int rl_eof;
+extern int rl_erase;
+extern int rl_intr;
+extern int rl_kill;
+extern int rl_quit;
+extern int rl_susp;
+
+void rl_ttyset(int);
+void rl_add_slash(char *, char *);
+
+COSMOPOLITAN_C_END_
+#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
+#endif /* COSMOPOLITAN_THIRD_PARTY_EDITLINE_INTERNAL_H_ */

third_party/editline/sysunix.c

@@ -0,0 +1,112 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ This program is free software; you can redistribute it and/or modify         │
+│ it under the terms of the GNU General Public License as published by         │
+│ the Free Software Foundation; version 2 of the License.                      │
+│                                                                              │
+│ This program is distributed in the hope that it will be useful, but          │
+│ WITHOUT ANY WARRANTY; without even the implied warranty of                   │
+│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU             │
+│ General Public License for more details.                                     │
+│                                                                              │
+│ You should have received a copy of the GNU General Public License            │
+│ along with this program; if not, write to the Free Software                  │
+│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA                │
+│ 02110-1301 USA                                                               │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/calls.h"
+#include "libc/calls/struct/stat.h"
+#include "libc/calls/termios.h"
+#include "libc/errno.h"
+#include "libc/log/log.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/termios.h"
+#include "third_party/editline/editline.h"
+#include "third_party/editline/internal.h"
+
+asm(".ident\t\"\\n\\n\
+Cosmopolitan Linenoise (BSD-like license)\\n\
+Copyright 2019 Justine Alexandra Roberts Tunney\\n\
+Copyright 1992,1993 Simmule Turner and Rich Salz\\n\
+All rights reserved.\\n\
+\\n\
+This software is not subject to any license of the American Telephone\\n\
+and Telegraph Company or of the Regents of the University of California.\\n\
+\\n\
+Permission is granted to anyone to use this software for any purpose on\\n\
+any computer system, and to alter it and redistribute it freely, subject\\n\
+to the following restrictions:\\n\
+1. The authors are not responsible for the consequences of use of this\\n\
+   software, no matter how awful, even if they arise from flaws in it.\\n\
+2. The origin of this software must not be misrepresented, either by\\n\
+   explicit claim or by omission.  Since few users ever read sources,\\n\
+   credits must appear in the documentation.\\n\
+3. Altered versions must be plainly marked as such, and must not be\\n\
+   misrepresented as being the original software.  Since few users\\n\
+   ever read sources, credits must appear in the documentation.\\n\
+4. This notice may not be removed or altered.\"");
+asm(".include \"libc/disclaimer.inc\"");
+
+/* Wrapper for tcgetattr */
+static int getattr(int fd, struct termios *arg) {
+  int result, retries = 3;
+  while (-1 == (result = tcgetattr(fd, arg)) && retries > 0) {
+    retries--;
+    if (EINTR == errno) continue;
+    break;
+  }
+  return result;
+}
+
+/* Wrapper for tcgetattr */
+static int setattr(int fd, int opt, const struct termios *arg) {
+  int result, retries = 3;
+  while (-1 == (result = tcsetattr(fd, opt, arg)) && retries > 0) {
+    retries--;
+    if (EINTR == errno) continue;
+    break;
+  }
+  return result;
+}
+
+void rl_ttyset(int Reset) {
+  static struct termios old;
+  struct termios new;
+  if (!Reset) {
+    if (-1 == getattr(0, &old)) {
+      perror("Failed tcgetattr()");
+    }
+    rl_erase = old.c_cc[VERASE];
+    rl_kill = old.c_cc[VKILL];
+    rl_eof = old.c_cc[VEOF];
+    rl_intr = old.c_cc[VINTR];
+    rl_quit = old.c_cc[VQUIT];
+#ifdef CONFIG_SIGSTOP
+    rl_susp = old.c_cc[VSUSP];
+#endif
+    new = old;
+    new.c_lflag &= ~(ECHO | ICANON | ISIG);
+    new.c_iflag &= ~INPCK;
+    if (rl_meta_chars)
+      new.c_iflag |= ISTRIP;
+    else
+      new.c_iflag &= ~ISTRIP;
+    new.c_cc[VMIN] = 1;
+    new.c_cc[VTIME] = 0;
+    if (-1 == setattr(0, TCSADRAIN, &new)) {
+      perror("Failed tcsetattr(TCSADRAIN)");
+    }
+  } else {
+    if (-1 == setattr(0, TCSADRAIN, &old)) {
+      perror("Failed tcsetattr(TCSADRAIN)");
+    }
+  }
+}
+
+void rl_add_slash(char *path, char *p) {
+  struct stat Sb;
+  if (stat(path, &Sb) >= 0) strcat(p, S_ISDIR(Sb.st_mode) ? "/" : " ");
+}