readline/examples/hist_purgecmd.c

   1 /* hist_purgecmd -- remove all instances of command or pattern from history
   2    file */
   3
   4 /* Copyright (C) 2011 Free Software Foundation, Inc.
   5
   6    This file is part of the GNU Readline Library (Readline), a library for
   7    reading lines of text with interactive input and history editing.
   8
   9    Readline is free software: you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation, either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    Readline is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with Readline.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22 #ifndef READLINE_LIBRARY
  23 #define READLINE_LIBRARY 1
  24 #endif
  25
  26 #include <unistd.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29
  30 #include <regex.h>
  31
  32 #ifdef READLINE_LIBRARY
  33 #  include "history.h"
  34 #else
  35 #  include <readline/history.h>
  36 #endif
  37
  38 #include <string.h>
  39
  40 #define STREQ(a, b) ((a)[0] == (b)[0] && strcmp(a, b) == 0)
  41 #define STREQN(a, b, n) ((n == 0) ? (1) \
  42                                   : ((a)[0] == (b)[0] && strncmp(a, b, n) == 0))
  43
  44 #define PURGE_REGEXP    0x01
  45
  46 static void
  47 usage()
  48 {
  49   fprintf (stderr, "hist_purgecmd: usage: hist_purgecmd [-r] [-t] [-f filename] command-spec\n");
  50   exit (2);
  51 }
  52
  53 int
  54 main (argc, argv)
  55      int argc;
  56      char **argv;
  57 {
  58   char *fn;
  59   int r, flags;
  60
  61   flags = 0;
  62   fn = 0;
  63   while ((r = getopt (argc, argv, "f:rt")) != -1)
  64     {
  65       switch (r)
  66         {
  67         case 'f':
  68           fn = optarg;
  69           break;
  70         case 'r':
  71           flags |= PURGE_REGEXP;
  72           break;
  73         case 't':
  74           history_write_timestamps = 1;
  75           break;
  76         default:
  77           usage ();
  78         }
  79     }
  80   argv += optind;
  81   argc -= optind;
  82
  83   if (fn == 0)
  84     fn = getenv ("HISTFILE");
  85   if (fn == 0)
  86     {
  87       fprintf (stderr, "hist_purgecmd: no history file\n");
  88       usage ();
  89     }
  90
  91   if ((r = read_history (fn)) != 0)
  92     {
  93       fprintf (stderr, "hist_purgecmd: read_history: %s: %s\n", fn, strerror (r));
  94       exit (1);
  95     }
  96
  97   for (r = 0; r < argc; r++)
  98     hist_purgecmd (argv[r], flags);
  99
 100   if ((r = write_history (fn)) != 0)
 101     {
 102       fprintf (stderr, "hist_purgecmd: write_history: %s: %s\n", fn, strerror (r));
 103       exit (1);
 104     }
 105
 106   exit (0);
 107 }
 108
 109 int
 110 hist_purgecmd (cmd, flags)
 111      char *cmd;
 112      int flags;
 113 {
 114   int r, n, rflags;
 115   HIST_ENTRY *temp;
 116   regex_t regex = { 0 };
 117
 118   if (flags & PURGE_REGEXP)
 119     {
 120       rflags = REG_EXTENDED|REG_NOSUB;
 121       if (regcomp (&regex, cmd, rflags))
 122         {
 123           fprintf (stderr, "hist_purgecmd: %s: invalid regular expression\n", cmd);
 124           return -1;
 125         }
 126     }
 127
 128   r = 0;
 129   using_history ();
 130   r = where_history ();
 131   for (n = 0; n < r; n++)
 132     {
 133       temp = history_get (n+history_base);
 134       if (((flags & PURGE_REGEXP) && (regexec (&regex, temp->line, 0, 0, 0) == 0)) ||
 135           ((flags & PURGE_REGEXP) == 0 && STREQ (temp->line, cmd)))
 136         {
 137           remove_history (n);
 138           r--;                  /* have to get one fewer now */
 139           n--;                  /* compensate for above increment */
 140           history_offset--;     /* moving backwards in history list */
 141         }
 142     }
 143   using_history ();
 144
 145   if (flags & PURGE_REGEXP)
 146     regfree (&regex);
 147
 148   return r;
 149 }