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 #include "concat.h"
  25
  26 char *
  27 concat (const char *s, ...)
  28 {
  29   va_list v;
  30
  31   va_start (v, s);
  32
  33   return vconcat (s, v);
  34 }
  35
  36 char *
  37 vconcat (const char *s, va_list v)
  38 {
  39   int len;
  40   char *rv, *arg;
  41   va_list save_v = v;
  42   int unc;
  43
  44   if (!s)
  45     return 0;
  46
  47   len = strlen (s);
  48
  49   unc = SLASH_P (*s) && SLASH_P (s[1]);
  50
  51   while (1)
  52     {
  53       arg = va_arg (v, char *);
  54       if (arg == 0)
  55         break;
  56       len += strlen (arg);
  57     }
  58   va_end (v);
  59
  60   rv = (char *) malloc (len + 1);
  61   strcpy (rv, s);
  62   v = save_v;
  63   while (1)
  64   {
  65     arg = va_arg (v, char *);
  66     if (arg == 0)
  67       break;
  68     strcat (rv, arg);
  69   }
  70   va_end (v);
  71
  72   char *d, *p;
  73   for (p = rv; *p; p++)
  74     if (*p == '\\')
  75       *p = '/';
  76
  77   /* concat is only used for urls and files, so we can safely
  78      canonicalize the results */
  79   for (p = d = rv; *p; p++)
  80     {
  81       *d++ = *p;
  82       /* special case for URLs */
  83       if (*p == ':' && p[1] == '/' && p[2] == '/' && p > rv + 1)
  84         {
  85           *d++ = *++p;
  86           *d++ = *++p;
  87         }
  88       else if (*p == '/' || *p == '\\')
  89         {
  90           if (p == rv && unc)
  91             p++;
  92           while (p[1] == '/')
  93             p++;
  94         }
  95     }
  96   *d = 0;
  97
  98   return rv;
  99 }
 100
 101 char *
 102 backslash (char *s)
 103 {
 104   for (char *t = s; *t; t++)
 105     if (*t == '/')
 106       *t = '\\';
 107   return s;
 108 }