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