X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fxreadlink.c;h=2f3b8a1098f66e9ebeb51b2713d162a7754d56b8;hb=95886da0b417a14882bb47bf4765f7af450d51da;hp=b58330a1d019e35007558569aa064b2c2529baee;hpb=b6f4a765056b52c30e9b44ca0990f536dd0cb9de;p=gnulib.git diff --git a/lib/xreadlink.c b/lib/xreadlink.c index b58330a1d..2f3b8a109 100644 --- a/lib/xreadlink.c +++ b/lib/xreadlink.c @@ -1,11 +1,11 @@ -/* exclude.c -- exclude file names +/* xreadlink.c -- readlink wrapper to return the link name in malloc'd storage - Copyright 2001 Free Software Foundation, Inc. + Copyright (C) 2001, 2003-2007, 2009-2014 Free Software Foundation, Inc. - This program is free software; you can redistribute it and/or modify + This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of @@ -13,80 +13,32 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with this program; see the file COPYING. - If not, write to the Free Software Foundation, - 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + along with this program. If not, see . */ -/* Written by Jim Meyering */ +/* Written by Jim Meyering + and Bruno Haible . */ -#if HAVE_CONFIG_H -# include -#endif +#include -#include -#include -#ifndef errno -extern int errno; -#endif - -#if HAVE_LIMITS_H -# include -#endif -#if HAVE_SYS_TYPES_H -# include -#endif -#if HAVE_STDLIB_H -# include -#endif -#if HAVE_UNISTD_H -# include -#endif +/* Specification. */ +#include "xreadlink.h" -#ifndef SIZE_MAX -# define SIZE_MAX ((size_t) -1) -#endif -#ifndef SSIZE_MAX -# define SSIZE_MAX ((ssize_t) (SIZE_MAX / 2)) -#endif +#include +#include "areadlink.h" #include "xalloc.h" -#include "xreadlink.h" /* Call readlink to get the symbolic link value of FILENAME. Return a pointer to that NUL-terminated string in malloc'd storage. - If readlink fails, return NULL (caller may use errno to diagnose). + If readlink fails, return NULL and set errno. If realloc fails, or if the link value is longer than SIZE_MAX :-), give a diagnostic and exit. */ char * xreadlink (char const *filename) { - /* The initial buffer size for the link value. A power of 2 - detects arithmetic overflow earlier, but is not required. */ - size_t buf_size = 128; - - while (1) - { - char *buffer = xmalloc (buf_size); - ssize_t link_length = readlink (filename, buffer, buf_size); - - if (link_length < 0) - { - int saved_errno = errno; - free (buffer); - errno = saved_errno; - return NULL; - } - - if (link_length < buf_size) - { - buffer[link_length] = 0; - return buffer; - } - - free (buffer); - buf_size *= 2; - if (SSIZE_MAX < buf_size || (SIZE_MAX / 2 < SSIZE_MAX && buf_size == 0)) - xalloc_die (); - } + char *result = areadlink (filename); + if (result == NULL && errno == ENOMEM) + xalloc_die (); + return result; }