lib/sh/strtrans.c

   1 /* strtrans.c - Translate and untranslate strings with ANSI-C escape
   2                 sequences. */
   3
   4 /* Copyright (C) 2000
   5    Free Software Foundation, Inc.
   6
   7    This file is part of GNU Bash, the Bourne Again SHell.
   8
   9    Bash is free software; you can redistribute it and/or modify it under
  10    the terms of the GNU General Public License as published by the Free
  11    Software Foundation; either version 2, or (at your option) any later
  12    version.
  13
  14    Bash is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17    for more details.
  18
  19    You should have received a copy of the GNU General Public License along
  20    with Bash; see the file COPYING.  If not, write to the Free Software
  21    Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA. */
  22
  23 #include <config.h>
  24
  25 #if defined (HAVE_UNISTD_H)
  26 #  include <unistd.h>
  27 #endif
  28
  29 #include "bashansi.h"
  30 #include <stdio.h>
  31 #include <ctype.h>
  32
  33 #include "shell.h"
  34
  35 #ifdef ESC
  36 #undef ESC
  37 #endif
  38 #define ESC '\033'      /* ASCII */
  39
  40 #ifndef ISOCTAL
  41 #define ISOCTAL(c)      ((c) >= '0' && (c) <= '7')
  42 #endif
  43
  44 #ifndef OCTVALUE
  45 #define OCTVALUE(c)     ((c) - '0')
  46 #endif
  47
  48 #ifndef isxdigit
  49 #  define isxdigit(c)   (isdigit((c)) || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F'))
  50 #endif
  51
  52 #define HEXVALUE(c) \
  53   ((c) >= 'a' && (c) <= 'f' ? (c)-'a'+10 : (c) >= 'A' && (c) <= 'F' ? (c)-'A'+10 : (c)-'0')
  54
  55 /* Convert STRING by expanding the escape sequences specified by the
  56    ANSI C standard.  If SAWC is non-null, recognize `\c' and use that
  57    as a string terminator.  If we see \c, set *SAWC to 1 before
  58    returning.  LEN is the length of STRING.  FOR_ECHO is a flag that
  59    means, if non-zero, that we're translating a string for `echo -e',
  60    and therefore should not treat a single quote as a character that
  61    may be escaped with a backslash. */
  62 char *
  63 ansicstr (string, len, for_echo, sawc, rlen)
  64      char *string;
  65      int len, for_echo, *sawc, *rlen;
  66 {
  67   int c, temp;
  68   char *ret, *r, *s;
  69
  70   if (string == 0 || *string == '\0')
  71     return ((char *)NULL);
  72
  73   ret = xmalloc (len + 1);
  74   for (r = ret, s = string; s && *s; )
  75     {
  76       c = *s++;
  77       if (c != '\\' || *s == '\0')
  78         *r++ = c;
  79       else
  80         {
  81           switch (c = *s++)
  82             {
  83 #if defined (__STDC__)
  84             case 'a': c = '\a'; break;
  85             case 'v': c = '\v'; break;
  86 #else
  87             case 'a': c = '\007'; break;
  88             case 'v': c = (int) 0x0B; break;
  89 #endif
  90             case 'b': c = '\b'; break;
  91             case 'e': case 'E':         /* ESC -- non-ANSI */
  92               c = ESC; break;
  93             case 'f': c = '\f'; break;
  94             case 'n': c = '\n'; break;
  95             case 'r': c = '\r'; break;
  96             case 't': c = '\t'; break;
  97             case '0': case '1': case '2': case '3':
  98             case '4': case '5': case '6': case '7':
  99               for (temp = 2, c -= '0'; ISOCTAL (*s) && temp--; s++)
 100                 c = (c * 8) + OCTVALUE (*s);
 101               break;
 102             case 'x':                   /* Hex digit -- non-ANSI */
 103               for (temp = 3, c = 0; isxdigit (*s) && temp--; s++)
 104                 c = (c * 16) + HEXVALUE (*s);
 105               /* \x followed by non-hex digits is passed through unchanged */
 106               if (temp == 3)
 107                 {
 108                   *r++ = '\\';
 109                   c = 'x';
 110                 }
 111               break;
 112             case '\\':
 113               break;
 114             case '\'':
 115               if (for_echo)
 116                 *r++ = '\\';
 117               break;
 118             case 'c':
 119               if (sawc)
 120                 {
 121                   *sawc = 1;
 122                   *r = '\0';
 123                   if (rlen)
 124                     *rlen = r - ret;
 125                   return ret;
 126                 }
 127             default:  *r++ = '\\'; break;
 128             }
 129           *r++ = c;
 130         }
 131     }
 132   *r = '\0';
 133   if (rlen)
 134     *rlen = r - ret;
 135   return ret;
 136 }
 137
 138 /* Take a string STR, possibly containing non-printing characters, and turn it
 139    into a $'...' ANSI-C style quoted string.  Returns a new string. */
 140 char *
 141 ansic_quote (str, flags, rlen)
 142      char *str;
 143      int flags, *rlen;
 144 {
 145   char *r, *ret, *s, obuf[8];
 146   int l, c, rsize, t;
 147
 148   if (str == 0 || *str == 0)
 149     return ((char *)0);
 150
 151   l = strlen (str);
 152   rsize = 2 * l + 4;
 153   r = ret = xmalloc (rsize);
 154
 155   *r++ = '$';
 156   *r++ = '\'';
 157
 158   for (s = str, l = 0; *s; s++)
 159     {
 160       c = *(unsigned char *)s;
 161       l = 1;            /* 1 == add backslash; 0 == no backslash */
 162       switch (c)
 163         {
 164         case ESC: c = 'E'; break;
 165 #ifdef __STDC__
 166         case '\a': c = 'a'; break;
 167         case '\v': c = 'v'; break;
 168 #else
 169         case '\007': c = 'a'; break;
 170         case 0x0b: c = 'v'; break;
 171 #endif
 172
 173         case '\b': c = 'b'; break;
 174         case '\f': c = 'f'; break;
 175         case '\n': c = 'n'; break;
 176         case '\r': c = 'r'; break;
 177         case '\t': c = 't'; break;
 178         case '\\':
 179         case '\'':
 180           break;
 181         default:
 182           if (isprint (c) == 0)
 183             {
 184               sprintf (obuf, "\\%.3o", c);
 185               t = r - ret;
 186               RESIZE_MALLOCED_BUFFER (ret, t, 5, rsize, 16);
 187               r = ret + t;      /* in case reallocated */
 188               for (t = 0; t < 4; t++)
 189                 *r++ = obuf[t];
 190               continue;
 191             }
 192           l = 0;
 193           break;
 194         }
 195       if (l)
 196         *r++ = '\\';
 197       *r++ = c;
 198     }
 199
 200   *r++ = '\'';
 201   *r = '\0';
 202   if (rlen)
 203     *rlen = r - ret;
 204   return ret;
 205 }