X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=lib%2Flstat.c;fp=lib%2Flstat.c;h=27a0cb5103dc500f5ed7dabd5ef34a8a1703df28;hb=c7e61475680fa226bd9b8bdd469cd66914e630f5;hp=0000000000000000000000000000000000000000;hpb=800deb09b422a73c1212233a93839a223ff59678;p=debian%2Fgzip diff --git a/lib/lstat.c b/lib/lstat.c new file mode 100644 index 0000000..27a0cb5 --- /dev/null +++ b/lib/lstat.c @@ -0,0 +1,92 @@ +/* Work around a bug of lstat on some systems + + Copyright (C) 1997-1999, 2000-2006, 2008-2009 Free Software + Foundation, Inc. + + 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 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 + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +/* written by Jim Meyering */ + +#include + +#if !HAVE_LSTAT +/* On systems that lack symlinks, our replacement already + defined lstat as stat, so there is nothing further to do other than + avoid an empty file. */ +typedef int dummy; +#else /* HAVE_LSTAT */ + +/* Get the original definition of lstat. It might be defined as a macro. */ +# define __need_system_sys_stat_h +# include +# include +# undef __need_system_sys_stat_h + +static inline int +orig_lstat (const char *filename, struct stat *buf) +{ + return lstat (filename, buf); +} + +/* Specification. */ +# include + +# include +# include + +/* lstat works differently on Linux and Solaris systems. POSIX (see + `pathname resolution' in the glossary) requires that programs like + `ls' take into consideration the fact that FILE has a trailing slash + when FILE is a symbolic link. On Linux and Solaris 10 systems, the + lstat function already has the desired semantics (in treating + `lstat ("symlink/", sbuf)' just like `lstat ("symlink/.", sbuf)', + but on Solaris 9 and earlier it does not. + + If FILE has a trailing slash and specifies a symbolic link, + then use stat() to get more info on the referent of FILE. + If the referent is a non-directory, then set errno to ENOTDIR + and return -1. Otherwise, return stat's result. */ + +int +rpl_lstat (const char *file, struct stat *sbuf) +{ + size_t len; + int lstat_result = orig_lstat (file, sbuf); + + if (lstat_result != 0) + return lstat_result; + + /* This replacement file can blindly check against '/' rather than + using the ISSLASH macro, because all platforms with '\\' either + lack symlinks (mingw) or have working lstat (cygwin) and thus do + not compile this file. 0 len should have already been filtered + out above, with a failure return of ENOENT. */ + len = strlen (file); + if (file[len - 1] != '/' || S_ISDIR (sbuf->st_mode)) + return 0; + + /* At this point, a trailing slash is only permitted on + symlink-to-dir; but it should have found information on the + directory, not the symlink. Call stat() to get info about the + link's referent. Our replacement stat guarantees valid results, + even if the symlink is not pointing to a directory. */ + if (!S_ISLNK (sbuf->st_mode)) + { + errno = ENOTDIR; + return -1; + } + return stat (file, sbuf); +} + +#endif /* HAVE_LSTAT */