IABSD.fr/xenocara/app/xedit/realpath.c

Branch : - branch - master - tag -

• Show log

  Commit

• Author : matthieu
  Date : 2006-11-25 20:07:29
  Hash : 616b6f15
  Message : Importing from X.Org 7.2RC2

• app/xedit/realpath.c

• /*
   * Copyright (c) 1994
   *	The Regents of the University of California.  All rights reserved.
   *
   * This code is derived from software contributed to Berkeley by
   * Jan-Simon Pendry.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  /* $XFree86: xc/programs/xedit/realpath.c,v 1.4 2000/02/12 20:45:45 dawes Exp $ */
  
  #if defined(LIBC_SCCS) && !defined(lint)
  static char sccsid[] = "@(#)realpath.c	8.1 (Berkeley) 2/16/94";
  #endif /* LIBC_SCCS and not lint */
  
  #include <sys/param.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  
  #include <errno.h>
  #include <fcntl.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #ifndef LISP
  #include "xedit.h"
  #endif
  
  #if defined(__Lynx__)
  #define NO_FCHDIR
  #endif
  
  #if defined(ISC)
  #ifndef MAXPATHLEN
  #define MAXPATHLEN	1024
  #endif
  #endif
  #ifndef MAXSYMLINKS
  #define MAXSYMLINKS	256
  #endif
  
  /*
   * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
   *
   * Find the real name of path, by removing all ".", ".." and symlink
   * components.  Returns (resolved) on success, or (NULL) on failure,
   * in which case the path which caused trouble is left in (resolved).
   */
  char *
  realpath(path, resolved)
  	const char *path;
  	char *resolved;
  {
  	struct stat sb;
  #ifdef NO_FCHDIR
  	char start[MAXPATHLEN];
  #else
  	int fd;
  #endif
  	int n, rootd, serrno;
  	char *p, *q, wbuf[MAXPATHLEN];
  	int symlinks = 0;
  
  	/* Save the starting point. */
  #ifdef NO_FCHDIR
  	if (getcwd(start, MAXPATHLEN) == NULL) {
  		(void)strcpy(resolved, ".");
  		return (NULL);
  	}
  #else
  	if ((fd = open(".", O_RDONLY)) < 0) {
  		(void)strcpy(resolved, ".");
  		return (NULL);
  	}
  #endif
  
  	/*
  	 * Find the dirname and basename from the path to be resolved.
  	 * Change directory to the dirname component.
  	 * lstat the basename part.
  	 *     if it is a symlink, read in the value and loop.
  	 *     if it is a directory, then change to that directory.
  	 * get the current directory name and append the basename.
  	 */
  	(void)strncpy(resolved, path, MAXPATHLEN - 1);
  	resolved[MAXPATHLEN - 1] = '\0';
  loop:
  	q = strrchr(resolved, '/');
  	if (q != NULL) {
  		p = q + 1;
  		if (q == resolved)
  			q = "/";
  		else {
  			do {
  				--q;
  			} while (q > resolved && *q == '/');
  			q[1] = '\0';
  			q = resolved;
  		}
  		if (chdir(q) < 0)
  			goto err1;
  	} else
  		p = resolved;
  
  	/* Deal with the last component. */
  	if (*p != '\0' && lstat(p, &sb) == 0) {
  		if (S_ISLNK(sb.st_mode)) {
                        if (++symlinks > MAXSYMLINKS) {
                                errno = ELOOP;
                                goto err1;
                        }
  			n = readlink(p, resolved, MAXPATHLEN);
  			if (n < 0)
  				goto err1;
  			resolved[n] = '\0';
  			goto loop;
  		}
  		if (S_ISDIR(sb.st_mode)) {
  			if (chdir(p) < 0)
  				goto err1;
  			p = "";
  		}
  	}
  
  	/*
  	 * Save the last component name and get the full pathname of
  	 * the current directory.
  	 */
  	(void)strcpy(wbuf, p);
  	if (getcwd(resolved, MAXPATHLEN) == 0)
  		goto err1;
  
  	/*
  	 * Join the two strings together, ensuring that the right thing
  	 * happens if the last component is empty, or the dirname is root.
  	 */
  	if (resolved[0] == '/' && resolved[1] == '\0')
  		rootd = 1;
  	else
  		rootd = 0;
  
  	if (*wbuf) {
  		if (strlen(resolved) + strlen(wbuf) + rootd + 1 > MAXPATHLEN) {
  			errno = ENAMETOOLONG;
  			goto err1;
  		}
  		if (rootd == 0)
  			(void)strcat(resolved, "/");
  		(void)strcat(resolved, wbuf);
  	}
  
  	/* Go back to where we came from. */
  #ifdef NO_FCHDIR
  	if (chdir(start) < 0)
  #else
  	if (fchdir(fd) < 0)
  #endif
  	{
  		serrno = errno;
  		goto err2;
  	}
  
  	/* It's okay if the close fails, what's an fd more or less? */
  #ifndef NO_FCHDIR
  	(void)close(fd);
  #endif
  	return (resolved);
  
  err1:	serrno = errno;
  #ifdef NO_FCHDIR
  	(void)chdir(start);
  #else
  	(void)fchdir(fd);
  #endif
  err2:
  #ifndef NO_FCHDIR
  	(void)close(fd);
  #endif
  	errno = serrno;
  	return (NULL);
  }