slang/slmisc.c

   1 /*
   2 Copyright (C) 2004, 2005, 2006 John E. Davis
   3
   4 This file is part of the S-Lang Library.
   5
   6 Trimmed down for use in GNU Midnight Commander.
   7
   8 The S-Lang Library is free software; you can redistribute it and/or
   9 modify it under the terms of the GNU General Public License as
  10 published by the Free Software Foundation; either version 2 of the
  11 License, or (at your option) any later version.
  12
  13 The S-Lang Library is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this library; if not, write to the Free Software
  20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  21 USA.
  22 */
  23
  24 #define _GNU_SOURCE
  25 #include "slinclud.h"
  26
  27 #include <ctype.h>
  28
  29 #include "slang.h"
  30 #include "_slang.h"
  31
  32
  33 char *SLmake_string(char *str)
  34 {
  35    return SLmake_nstring(str, strlen (str));
  36 }
  37
  38 char *SLmake_nstring (char *str, unsigned int n)
  39 {
  40    char *ptr;
  41
  42    if (NULL == (ptr = SLmalloc(n + 1)))
  43      {
  44         return NULL;
  45      }
  46    SLMEMCPY (ptr, str, n);
  47    ptr[n] = 0;
  48    return(ptr);
  49 }
  50
  51 /*
  52  * This function assumes that the initial \ char has been removed.
  53  */
  54 char *_pSLexpand_escaped_char(char *p, SLwchar_Type *ch, int *isunicodep)
  55 {
  56    int i = 0;
  57    SLwchar_Type max = 0;
  58    SLwchar_Type num, base = 0;
  59    SLwchar_Type ch1;
  60    int isunicode;
  61    int needs_brace;
  62
  63    ch1 = *p++;
  64    isunicode = 0;
  65    needs_brace = 0;
  66
  67    switch (ch1)
  68      {
  69       default: num = ch1; break;
  70       case 'n': num = '\n'; break;
  71       case 't': num = '\t'; break;
  72       case 'v': num = '\v'; break;
  73       case 'b': num = '\b'; break;
  74       case 'r': num = '\r'; break;
  75       case 'f': num = '\f'; break;
  76       case 'E': case 'e': num = 27; break;
  77       case 'a': num = 7;
  78         break;
  79
  80         /* octal */
  81       case '0': case '1': case '2': case '3':
  82       case '4': case '5': case '6': case '7':
  83         max = '7';
  84         base = 8; i = 2; num = ch1 - '0';
  85         break;
  86
  87       case 'd':                        /* decimal -- S-Lang extension */
  88         base = 10;
  89         i = 3;
  90         max = '9';
  91         num = 0;
  92         break;
  93
  94       case 'u':
  95         isunicode = 1;
  96         /* drop */
  97       case 'x':                        /* hex */
  98         base = 16;
  99         max = '9';
 100         i = 2;
 101         num = 0;
 102
 103         if (*p == '{')
 104           {
 105              p++;
 106              i = 0;
 107              while (p[i] && (p[i] != '}'))
 108                i++;
 109              if (p[i] != '}')
 110                {
 111                   SLang_verror (SL_SYNTAX_ERROR, "Escaped character missing closing }.");
 112                   return NULL;
 113                }
 114              /* The meaning of \x{...} is mode dependent.  If in UTF-8 mode, then
 115               * \x{...} always generates a unicode character.  Otherwise, the
 116               * meaning of \x{...} depends upon the number of characters enclosed
 117               * by the brace.  If there are less than 3, then assume no unicode.
 118               * If greater than or equal to 3, then assume unicode.
 119               */
 120              if (isunicode == 0)       /* \x... */
 121                isunicode = _pSLinterp_UTF8_Mode || (i > 2);
 122              needs_brace = 1;
 123           }
 124         break;
 125      }
 126
 127    while (i)
 128      {
 129         ch1 = *p;
 130
 131         i--;
 132
 133         if ((ch1 <= max) && (ch1 >= '0'))
 134           {
 135              num = base * num + (ch1 - '0');
 136           }
 137         else if (base == 16)
 138           {
 139              ch1 |= 0x20;
 140              if ((ch1 < 'a') || ((ch1 > 'f'))) break;
 141              num = base * num + 10 + (ch1 - 'a');
 142           }
 143         else break;
 144         p++;
 145      }
 146
 147    if (needs_brace)
 148      {
 149         if (*p != '}')
 150           {
 151              SLang_verror (SL_SYNTAX_ERROR, "Malformed escaped character.");
 152              return NULL;
 153           }
 154         p++;
 155      }
 156
 157    if (isunicodep != NULL)
 158      *isunicodep = isunicode;
 159
 160    *ch = num;
 161    return p;
 162 }