lib/sh/shquote.c

   1 /* Copyright (C) 1999 Free Software Foundation, Inc.
   2
   3    This file is part of GNU Bash, the Bourne Again SHell.
   4
   5    Bash is free software; you can redistribute it and/or modify it under
   6    the terms of the GNU General Public License as published by the Free
   7    Software Foundation; either version 2, or (at your option) any later
   8    version.
   9
  10    Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  11    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13    for more details.
  14
  15    You should have received a copy of the GNU General Public License along
  16    with Bash; see the file COPYING.  If not, write to the Free Software
  17    Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  18
  19 #include <config.h>
  20
  21 #if defined (HAVE_UNISTD_H)
  22 #  ifdef _MINIX
  23 #    include <sys/types.h>
  24 #  endif
  25 #  include <unistd.h>
  26 #endif
  27
  28 #include <stdio.h>
  29
  30 #include "syntax.h"
  31 #include <xmalloc.h>
  32
  33 /* **************************************************************** */
  34 /*                                                                  */
  35 /*       Functions for quoting strings to be re-read as input       */
  36 /*                                                                  */
  37 /* **************************************************************** */
  38
  39 /* Return a new string which is the single-quoted version of STRING.
  40    Used by alias and trap, among others. */
  41 char *
  42 sh_single_quote (string)
  43      char *string;
  44 {
  45   register int c;
  46   char *result, *r, *s;
  47
  48   result = (char *)xmalloc (3 + (4 * strlen (string)));
  49   r = result;
  50   *r++ = '\'';
  51
  52   for (s = string; s && (c = *s); s++)
  53     {
  54       *r++ = c;
  55
  56       if (c == '\'')
  57         {
  58           *r++ = '\\';  /* insert escaped single quote */
  59           *r++ = '\'';
  60           *r++ = '\'';  /* start new quoted string */
  61         }
  62     }
  63
  64   *r++ = '\'';
  65   *r = '\0';
  66
  67   return (result);
  68 }
  69
  70 /* Quote STRING using double quotes.  Return a new string. */
  71 char *
  72 sh_double_quote (string)
  73      char *string;
  74 {
  75   register unsigned char c;
  76   char *result, *r, *s;
  77
  78   result = (char *)xmalloc (3 + (2 * strlen (string)));
  79   r = result;
  80   *r++ = '"';
  81
  82   for (s = string; s && (c = *s); s++)
  83     {
  84       if (sh_syntaxtab[c] & CBSDQUOTE)
  85         *r++ = '\\';
  86
  87       *r++ = c;
  88     }
  89
  90   *r++ = '"';
  91   *r = '\0';
  92
  93   return (result);
  94 }
  95
  96 /* Remove backslashes that are quoting characters that are special between
  97    double quotes.  Return a new string. */
  98 char *
  99 sh_un_double_quote (string)
 100      char *string;
 101 {
 102   register int c, pass_next;
 103   char *result, *r, *s;
 104
 105   r = result = (char *)xmalloc (strlen (string) + 1);
 106
 107   for (pass_next = 0, s = string; s && (c = *s); s++)
 108     {
 109       if (pass_next)
 110         {
 111           *r++ = c;
 112           pass_next = 0;
 113           continue;
 114         }
 115       if (c == '\\' && (sh_syntaxtab[(unsigned char) s[1]] & CBSDQUOTE))
 116         {
 117           pass_next = 1;
 118           continue;
 119         }
 120       *r++ = c;
 121     }
 122
 123   *r = '\0';
 124   return result;
 125 }
 126
 127 /* Quote special characters in STRING using backslashes.  Return a new
 128    string. */
 129 char *
 130 sh_backslash_quote (string)
 131      char *string;
 132 {
 133   int c;
 134   char *result, *r, *s;
 135
 136   result = (char *)xmalloc (2 * strlen (string) + 1);
 137
 138   for (r = result, s = string; s && (c = *s); s++)
 139     {
 140       switch (c)
 141         {
 142         case ' ': case '\t': case '\n':         /* IFS white space */
 143         case '\'': case '"': case '\\':         /* quoting chars */
 144         case '|': case '&': case ';':           /* shell metacharacters */
 145         case '(': case ')': case '<': case '>':
 146         case '!': case '{': case '}':           /* reserved words */
 147         case '*': case '[': case '?': case ']': /* globbing chars */
 148         case '^':
 149         case '$': case '`':                     /* expansion chars */
 150         case ',':                               /* brace expansion */
 151           *r++ = '\\';
 152           *r++ = c;
 153           break;
 154 #if 0
 155         case '~':                               /* tilde expansion */
 156           if (s == string || s[-1] == '=' || s[-1] == ':')
 157             *r++ = '\\';
 158           *r++ = c;
 159           break;
 160 #endif
 161         case '#':                               /* comment char */
 162           if (s == string)
 163             *r++ = '\\';
 164           /* FALLTHROUGH */
 165         default:
 166           *r++ = c;
 167           break;
 168         }
 169     }
 170
 171   *r = '\0';
 172   return (result);
 173 }
 174
 175 #if defined (PROMPT_STRING_DECODE)
 176 /* Quote characters that get special treatment when in double quotes in STRING
 177    using backslashes.  Return a new string. */
 178 char *
 179 sh_backslash_quote_for_double_quotes (string)
 180      char *string;
 181 {
 182   unsigned char c;
 183   char *result, *r, *s;
 184
 185   result = (char *)xmalloc (2 * strlen (string) + 1);
 186
 187   for (r = result, s = string; s && (c = *s); s++)
 188     {
 189       if (sh_syntaxtab[c] & CBSDQUOTE)
 190         *r++ = '\\';
 191
 192       *r++ = c;
 193     }
 194
 195   *r = '\0';
 196   return (result);
 197 }
 198 #endif /* PROMPT_STRING_DECODE */
 199
 200 int
 201 sh_contains_shell_metas (string)
 202      char *string;
 203 {
 204   char *s;
 205
 206   for (s = string; s && *s; s++)
 207     {
 208       switch (*s)
 209         {
 210         case ' ': case '\t': case '\n':         /* IFS white space */
 211         case '\'': case '"': case '\\':         /* quoting chars */
 212         case '|': case '&': case ';':           /* shell metacharacters */
 213         case '(': case ')': case '<': case '>':
 214         case '!': case '{': case '}':           /* reserved words */
 215         case '*': case '[': case '?': case ']': /* globbing chars */
 216         case '^':
 217         case '$': case '`':                     /* expansion chars */
 218           return (1);
 219         case '~':                               /* tilde expansion */
 220           if (s == string || s[-1] == '=' || s[-1] == ':')
 221             return (1);
 222           break;
 223         case '#':
 224           if (s == string)                      /* comment char */
 225             return (1);
 226           /* FALLTHROUGH */
 227         default:
 228           break;
 229         }
 230     }
 231
 232   return (0);
 233 }