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Diffstat (limited to 'lib/lstat.c')
| -rw-r--r-- | lib/lstat.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/lib/lstat.c b/lib/lstat.c new file mode 100644 index 0000000..f74392b --- /dev/null +++ b/lib/lstat.c @@ -0,0 +1,104 @@ +/* Work around a bug of lstat on some systems + + Copyright (C) 1997-2006, 2008-2020 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 <https://www.gnu.org/licenses/>. */ + +/* written by Jim Meyering */ + +/* If the user's config.h happens to include <sys/stat.h>, let it include only + the system's <sys/stat.h> here, so that orig_lstat doesn't recurse to + rpl_lstat. */ +#define __need_system_sys_stat_h +#include <config.h> + +#if !HAVE_LSTAT +/* On systems that lack symlinks, our replacement <sys/stat.h> 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. */ +# include <sys/types.h> +# include <sys/stat.h> +# undef __need_system_sys_stat_h + +static int +orig_lstat (const char *filename, struct stat *buf) +{ + return lstat (filename, buf); +} + +/* Specification. */ +# ifdef __osf__ +/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc + eliminates this include because of the preliminary #include <sys/stat.h> + above. */ +# include "sys/stat.h" +# else +# include <sys/stat.h> +# endif + +# include "stat-time.h" + +# include <string.h> +# include <errno.h> + +/* 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) +{ + int result = orig_lstat (file, sbuf); + + /* 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. */ + if (result == 0) + { + if (S_ISDIR (sbuf->st_mode) || file[strlen (file) - 1] != '/') + result = stat_time_normalize (result, sbuf); + else + { + /* At this point, a trailing slash is permitted only 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; + } + result = stat (file, sbuf); + } + } + return result; +} + +#endif /* HAVE_LSTAT */ |