concat.cc

   1 /*
   2  * Copyright (c) 2000, Red Hat, Inc.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by DJ Delorie <dj@cygnus.com>
  13  *
  14  */
  15
  16 /* See concat.h.  Note that we canonicalize the result, this avoids
  17    multiple slashes being interpreted as UNCs. */
  18
  19 #include <stdarg.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22
  23 char *
  24 concat (char *s, ...)
  25 {
  26   int len;
  27   char *rv, *arg;
  28   va_list v;
  29
  30   if (!s)
  31     return 0;
  32
  33   len = strlen (s);
  34
  35   va_start (v, s);
  36   while (1)
  37     {
  38       arg = va_arg (v, char *);
  39       if (arg == 0)
  40         break;
  41       len += strlen (arg);
  42     }
  43   va_end (v);
  44
  45   rv = (char *) malloc (len+1);
  46   strcpy (rv, s);
  47   va_start (v, s);
  48   while (1)
  49   {
  50     arg = va_arg (v, char *);
  51     if (arg == 0)
  52       break;
  53     strcat (rv, arg);
  54   }
  55   va_end (v);
  56
  57   /* concat is only used for urls and files, so we can safely
  58      canonicalize the results */
  59   char *d;
  60   for (s=rv; *s; s++)
  61     if (*s == '\\')
  62       *s = '/';
  63   for (s=d=rv; *s; s++)
  64     {
  65       *d++ = *s;
  66       /* special case for URLs */
  67       if (*s == ':' && s[1] == '/' &&s[2] == '/')
  68         {
  69           *d++ = *++s;
  70           *d++ = *++s;
  71         }
  72       else if (*s == '/')
  73         while (s[1] == '/')
  74           s++;
  75     }
  76   *d = 0;
  77
  78   return rv;
  79 }
  80
  81 char *
  82 backslash (char *s)
  83 {
  84   for (char *t = s; *t; t++)
  85     if (*t == '/')
  86       *t = '\\';
  87   return s;
  88 }