1/* vi: set sw=4 ts=4: */ 2/* 3 * bb_simplify_path implementation for busybox 4 * 5 * Copyright (C) 2001 Manuel Novoa III <mjn3@codepoet.org> 6 * 7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. 8 */ 9 10#include "libbb.h" 11 12char *bb_simplify_path(const char *path) 13{ 14 char *s, *start, *p; 15 16 if (path[0] == '/') 17 start = xstrdup(path); 18 else { 19 s = xrealloc_getcwd_or_warn(NULL); 20 start = concat_path_file(s, path); 21 free(s); 22 } 23 p = s = start; 24 25 do { 26 if (*p == '/') { 27 if (*s == '/') { /* skip duplicate (or initial) slash */ 28 continue; 29 } 30 if (*s == '.') { 31 if (s[1] == '/' || !s[1]) { /* remove extra '.' */ 32 continue; 33 } 34 if ((s[1] == '.') && (s[2] == '/' || !s[2])) { 35 ++s; 36 if (p > start) { 37 while (*--p != '/') /* omit previous dir */ 38 continue; 39 } 40 continue; 41 } 42 } 43 } 44 *++p = *s; 45 } while (*++s); 46 47 if ((p == start) || (*p != '/')) { /* not a trailing slash */ 48 ++p; /* so keep last character */ 49 } 50 *p = 0; 51 52 return start; 53} 54