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
  32 extern char *xmalloc ();
  33
  34 /* **************************************************************** */
  35 /*                                                                  */
  36 /*       Functions for quoting strings to be re-read as input       */
  37 /*                                                                  */
  38 /* **************************************************************** */
  39
  40 /* Return a new string which is the single-quoted version of STRING.
  41    Used by alias and trap, among others. */
  42 char *
  43 sh_single_quote (string)
  44      char *string;
  45 {
  46   register int c;
  47   char *result, *r, *s;
  48
  49   result = xmalloc (3 + (4 * strlen (string)));
  50   r = result;
  51   *r++ = '\'';
  52
  53   for (s = string; s && (c = *s); s++)
  54     {
  55       *r++ = c;
  56
  57       if (c == '\'')
  58         {
  59           *r++ = '\\';  /* insert escaped single quote */
  60           *r++ = '\'';
  61           *r++ = '\'';  /* start new quoted string */
  62         }
  63     }
  64
  65   *r++ = '\'';
  66   *r = '\0';
  67
  68   return (result);
  69 }
  70
  71 /* Quote STRING using double quotes.  Return a new string. */
  72 char *
  73 sh_double_quote (string)
  74      char *string;
  75 {
  76   register int c;
  77   char *result, *r, *s;
  78
  79   result = xmalloc (3 + (2 * strlen (string)));
  80   r = result;
  81   *r++ = '"';
  82
  83   for (s = string; s && (c = *s); s++)
  84     {
  85       if (sh_syntaxtab[c] & CBSDQUOTE)
  86         *r++ = '\\';
  87
  88       *r++ = c;
  89     }
  90
  91   *r++ = '"';
  92   *r = '\0';
  93
  94   return (result);
  95 }
  96
  97 /* Remove backslashes that are quoting characters that are special between
  98    double quotes.  Return a new string. */
  99 char *
 100 sh_un_double_quote (string)
 101      char *string;
 102 {
 103   register int c, pass_next;
 104   char *result, *r, *s;
 105
 106   r = result = xmalloc (strlen (string) + 1);
 107
 108   for (pass_next = 0, s = string; s && (c = *s); s++)
 109     {
 110       if (pass_next)
 111         {
 112           *r++ = c;
 113           pass_next = 0;
 114           continue;
 115         }
 116       if (c == '\\' && (sh_syntaxtab[s[1]] & CBSDQUOTE))
 117         {
 118           pass_next = 1;
 119           continue;
 120         }
 121       *r++ = c;
 122     }
 123
 124   *r = '\0';
 125   return result;
 126 }
 127
 128 /* Quote special characters in STRING using backslashes.  Return a new
 129    string. */
 130 char *
 131 sh_backslash_quote (string)
 132      char *string;
 133 {
 134   int c;
 135   char *result, *r, *s;
 136
 137   result = xmalloc (2 * strlen (string) + 1);
 138
 139   for (r = result, s = string; s && (c = *s); s++)
 140     {
 141       switch (c)
 142         {
 143         case ' ': case '\t': case '\n':         /* IFS white space */
 144         case '\'': case '"': case '\\':         /* quoting chars */
 145         case '|': case '&': case ';':           /* shell metacharacters */
 146         case '(': case ')': case '<': case '>':
 147         case '!': case '{': case '}':           /* reserved words */
 148         case '*': case '[': case '?': case ']': /* globbing chars */
 149         case '^':
 150         case '$': case '`':                     /* expansion chars */
 151           *r++ = '\\';
 152           *r++ = c;
 153           break;
 154 #if 0
 155         case '~':                               /* tilde expansion */
 156           if (s == string || s[-1] == '=' || s[-1] == ':')
 157             *r++ = '\\';
 158           *r++ = c;
 159           break;
 160 #endif
 161         case '#':                               /* comment char */
 162           if (s == string)
 163             *r++ = '\\';
 164           /* FALLTHROUGH */
 165         default:
 166           *r++ = c;
 167           break;
 168         }
 169     }
 170
 171   *r = '\0';
 172   return (result);
 173 }
 174
 175 #if defined (PROMPT_STRING_DECODE)
 176 /* Quote characters that get special treatment when in double quotes in STRING
 177    using backslashes.  Return a new string. */
 178 char *
 179 sh_backslash_quote_for_double_quotes (string)
 180      char *string;
 181 {
 182   int c;
 183   char *result, *r, *s;
 184
 185   result = xmalloc (2 * strlen (string) + 1);
 186
 187   for (r = result, s = string; s && (c = *s); s++)
 188     {
 189       if (sh_syntaxtab[c] & CBSDQUOTE)
 190         *r++ = '\\';
 191
 192       *r++ = c;
 193     }
 194
 195   *r = '\0';
 196   return (result);
 197 }
 198 #endif /* PROMPT_STRING_DECODE */
 199
 200 int
 201 sh_contains_shell_metas (string)
 202      char *string;
 203 {
 204   char *s;
 205
 206   for (s = string; s && *s; s++)
 207     {
 208       switch (*s)
 209         {
 210         case ' ': case '\t': case '\n':         /* IFS white space */
 211         case '\'': case '"': case '\\':         /* quoting chars */
 212         case '|': case '&': case ';':           /* shell metacharacters */
 213         case '(': case ')': case '<': case '>':
 214         case '!': case '{': case '}':           /* reserved words */
 215         case '*': case '[': case '?': case ']': /* globbing chars */
 216         case '^':
 217         case '$': case '`':                     /* expansion chars */
 218           return (1);
 219         case '~':                               /* tilde expansion */
 220           if (s == string || s[-1] == '=' || s[-1] == ':')
 221             return (1);
 222         case '#':
 223           if (s == string)                      /* comment char */
 224             return (1);
 225           /* FALLTHROUGH */
 226         default:
 227           break;
 228         }
 229     }
 230
 231   return (0);
 232 }