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 static char *cvsid = "\n%%% $Id$\n";
  20
  21 #include <stdarg.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 char *
  26 concat (char *s, ...)
  27 {
  28   int len;
  29   char *rv, *arg;
  30   va_list v;
  31
  32   if (!s)
  33     return 0;
  34
  35   len = strlen (s);
  36
  37   va_start (v, s);
  38   while (1)
  39     {
  40       arg = va_arg (v, char *);
  41       if (arg == 0)
  42         break;
  43       len += strlen (arg);
  44     }
  45   va_end (v);
  46
  47   rv = (char *) malloc (len+1);
  48   strcpy (rv, s);
  49   va_start (v, s);
  50   while (1)
  51   {
  52     arg = va_arg (v, char *);
  53     if (arg == 0)
  54       break;
  55     strcat (rv, arg);
  56   }
  57   va_end (v);
  58
  59   /* concat is only used for urls and files, so we can safely
  60      canonicalize the results */
  61   char *d;
  62   for (s=rv; *s; s++)
  63     if (*s == '\\')
  64       *s = '/';
  65   for (s=d=rv; *s; s++)
  66     {
  67       *d++ = *s;
  68       /* special case for URLs */
  69       if (*s == ':' && s[1] == '/' && s[2] == '/' && s > rv+1)
  70         {
  71           *d++ = *++s;
  72           *d++ = *++s;
  73         }
  74       else if (*s == '/')
  75         while (s[1] == '/')
  76           s++;
  77     }
  78   *d = 0;
  79
  80   return rv;
  81 }
  82
  83 char *
  84 backslash (char *s)
  85 {
  86   for (char *t = s; *t; t++)
  87     if (*t == '/')
  88       *t = '\\';
  89   return s;
  90 }