LXR busybox/libbb/simplify

   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 source tree.
   8 */
   9#include "libbb.h"
  10
  11char* FAST_FUNC bb_simplify_abs_path_inplace(char *start)
  12{
  13        char *s, *p;
  14
  15        p = s = start;
  16        do {
  17                if (*p == '/') {
  18                        if (*s == '/') {  /* skip duplicate (or initial) slash */
  19                                continue;
  20                        }
  21                        if (*s == '.') {
  22                                if (s[1] == '/' || !s[1]) {  /* remove extra '.' */
  23                                        continue;
  24                                }
  25                                if ((s[1] == '.') && (s[2] == '/' || !s[2])) {
  26                                        ++s;
  27                                        if (p > start) {
  28                                                while (*--p != '/')  /* omit previous dir */
  29                                                        continue;
  30                                        }
  31                                        continue;
  32                                }
  33                        }
  34                }
  35                *++p = *s;
  36        } while (*++s);
  37
  38        if ((p == start) || (*p != '/')) {  /* not a trailing slash */
  39                ++p;  /* so keep last character */
  40        }
  41        *p = '\0';
  42        return p;
  43}
  44
  45char* FAST_FUNC bb_simplify_path(const char *path)
  46{
  47        char *s, *p;
  48
  49        if (path[0] == '/')
  50                s = xstrdup(path);
  51        else {
  52                p = xrealloc_getcwd_or_warn(NULL);
  53                s = concat_path_file(p, path);
  54                free(p);
  55        }
  56
  57        bb_simplify_abs_path_inplace(s);
  58        return s;
  59}
  60