usr/src/lib/libast/common/path/pathrepl.c

   1 /***********************************************************************
   2 *                                                                      *
   3 *               This software is part of the ast package               *
   4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
   5 *                      and is licensed under the                       *
   6 *                  Common Public License, Version 1.0                  *
   7 *                    by AT&T Intellectual Property                     *
   8 *                                                                      *
   9 *                A copy of the License is available at                 *
  10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
  11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
  12 *                                                                      *
  13 *              Information and Software Systems Research               *
  14 *                            AT&T Research                             *
  15 *                           Florham Park NJ                            *
  16 *                                                                      *
  17 *                 Glenn Fowler <gsf@research.att.com>                  *
  18 *                  David Korn <dgk@research.att.com>                   *
  19 *                   Phong Vo <kpv@research.att.com>                    *
  20 *                                                                      *
  21 ***********************************************************************/
  22 #pragma prototyped
  23 /*
  24  * Glenn Fowler
  25  * AT&T Bell Laboratories
  26  *
  27  * in place replace of first occurrence of /match/ with /replace/ in path
  28  * end of path returned
  29  */
  30
  31 #include <ast.h>
  32
  33 char*
  34 pathrepl(register char* path, const char* match, register const char* replace)
  35 {
  36         register const char*    m = match;
  37         register const char*    r;
  38         char*                   t;
  39
  40         if (!match) match = "";
  41         if (!replace) replace = "";
  42         if (streq(match, replace))
  43                 return(path + strlen(path));
  44         for (;;)
  45         {
  46                 while (*path && *path++ != '/');
  47                 if (!*path) break;
  48                 if (*path == *m)
  49                 {
  50                         t = path;
  51                         while (*m && *m++ == *path) path++;
  52                         if (!*m && *path == '/')
  53                         {
  54                                 register char*  p;
  55
  56                                 p = t;
  57                                 r = replace;
  58                                 while (p < path && *r) *p++ = *r++;
  59                                 if (p < path) while (*p++ = *path++);
  60                                 else if (*r && p >= path)
  61                                 {
  62                                         register char*  u;
  63
  64                                         t = path + strlen(path);
  65                                         u = t + strlen(r);
  66                                         while (t >= path) *u-- = *t--;
  67                                         while (*r) *p++ = *r++;
  68                                 }
  69                                 else p += strlen(p) + 1;
  70                                 return(p - 1);
  71                         }
  72                         path = t;
  73                         m = match;
  74                 }
  75         }
  76         return(path);
  77 }