openblt

a hobby OS from the late 90s
git clone http://frotz.net/git/openblt.git
Log | Files | Refs | LICENSE

path.c (2608B)


      1 /* $Id: //depot/blt/srv/vfs/path.c#2 $
      2 **
      3 ** Copyright 1999 Sidney Cammeresi.
      4 ** All rights reserved.
      5 **
      6 ** Redistribution and use in source and binary forms, with or without
      7 ** modification, are permitted provided that the following conditions
      8 ** are met:
      9 ** 1. Redistributions of source code must retain the above copyright
     10 **    notice, this list of conditions, and the following disclaimer.
     11 ** 2. Redistributions in binary form must reproduce the above copyright
     12 **    notice, this list of conditions, and the following disclaimer in the
     13 **    documentation and/or other materials provided with the distribution.
     14 ** 3. The name of the author may not be used to endorse or promote products
     15 **    derived from this software without specific prior written permission.
     16 **
     17 ** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     18 ** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     19 ** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     20 ** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     21 ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     22 ** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26 ** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 */
     28 
     29 #include <stdlib.h>
     30 #include "path.h"
     31 
     32 char *path_concat (char *s, const char *t)
     33 {
     34 	char *c;
     35 
     36 	c = s;
     37 	while (*c++) ;
     38 	c--;
     39 
     40 	while (*t) /* for each component */
     41 		if (*t == '/')
     42 			*c++ = *t++;
     43 		else if (*t != '.') /* normal component */
     44 			while (*t && (*t != '/'))
     45 				*c++ = *t++;
     46 		else /* doesn't begin with . or / */
     47 		{   
     48 			t++;
     49 			if ((*t == '/') || !*t) /* ./ component */
     50 				t++;
     51 			else if (*t == '.') /* ../ component */
     52 			{   
     53 				if (c != s + 1) /* can't .. from the root dir */
     54 				{   
     55 					c -= 2;
     56 					while ((c != s) && (*c != '/'))
     57 						c--;
     58 					c++;
     59 					t++;
     60 					if (*t == '/')
     61 						t++;
     62 				}
     63 			}
     64 			else /* component beginning with a period */
     65 			{   
     66 				*c++ = '.';
     67 				while (*t && (*t != '/'))
     68 					*c++ = *t++;
     69 			}
     70 		}
     71 
     72 	*c = 0;
     73 	if (((c - 1) != s) && (c[-1] == '/'))
     74 		c[-1] = 0;
     75 
     76 	return s;
     77 }
     78 
     79 char *path_combine (const char *s, const char *t, char *d)
     80 {
     81 	const char *c;
     82 	char *node;
     83 
     84 	*d = 0;
     85 	node = d;
     86 	if (*t == '/')
     87 		return path_concat (node, t);
     88 
     89 	c = s;
     90 	while (*c)
     91 		*d++ = *c++;
     92 	if (*d != '/')
     93 		*d++ = '/';
     94 
     95 	return path_concat (node, t);
     96 }
     97