diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Makefile.am | 2 | ||||
| -rw-r--r-- | lib/careadlinkat.c | 16 | ||||
| -rw-r--r-- | lib/careadlinkat.h | 6 | ||||
| -rw-r--r-- | lib/dirent.in.h | 258 | ||||
| -rw-r--r-- | lib/fdopendir.c | 204 | ||||
| -rw-r--r-- | lib/fstatat.c | 135 | ||||
| -rw-r--r-- | lib/gnulib.mk | 97 | ||||
| -rw-r--r-- | lib/openat-die.c | 6 | ||||
| -rw-r--r-- | lib/openat-priv.h | 64 | ||||
| -rw-r--r-- | lib/openat-proc.c | 110 | ||||
| -rw-r--r-- | lib/openat.h | 120 | ||||
| -rw-r--r-- | lib/readlinkat.c | 47 | ||||
| -rw-r--r-- | lib/save-cwd.c | 3 | ||||
| -rw-r--r-- | lib/save-cwd.h | 46 |
14 files changed, 1093 insertions, 21 deletions
diff --git a/lib/Makefile.am b/lib/Makefile.am index 28fdafd4b45..a341609e895 100644 --- a/lib/Makefile.am +++ b/lib/Makefile.am @@ -8,3 +8,5 @@ AM_CFLAGS = $(GNULIB_WARN_CFLAGS) $(WERROR_CFLAGS) DEFAULT_INCLUDES = -I. -I$(top_srcdir)/lib -I../src -I$(top_srcdir)/src include gnulib.mk + +libgnu_a_SOURCES += openat-die.c save-cwd.c diff --git a/lib/careadlinkat.c b/lib/careadlinkat.c index 1a759be7caf..d242ffaac7d 100644 --- a/lib/careadlinkat.c +++ b/lib/careadlinkat.c @@ -24,9 +24,7 @@ #include <errno.h> #include <limits.h> -#include <stdlib.h> #include <string.h> -#include <unistd.h> /* Define this independently so that stdint.h is not a prerequisite. */ #ifndef SIZE_MAX @@ -39,20 +37,6 @@ #include "allocator.h" -/* Get the symbolic link value of FILENAME and put it into BUFFER, with - size BUFFER_SIZE. This function acts like readlink but has - readlinkat's signature. */ -ssize_t -careadlinkatcwd (int fd, char const *filename, char *buffer, - size_t buffer_size) -{ - /* FD must be AT_FDCWD here, otherwise the caller is using this - function in contexts for which it was not meant for. */ - if (fd != AT_FDCWD) - abort (); - return readlink (filename, buffer, buffer_size); -} - /* Assuming the current directory is FD, get the symbolic link value of FILENAME as a null-terminated string and put it into a buffer. If FD is AT_FDCWD, FILENAME is interpreted relative to the current diff --git a/lib/careadlinkat.h b/lib/careadlinkat.h index 5cdb813fedd..965573bef3a 100644 --- a/lib/careadlinkat.h +++ b/lib/careadlinkat.h @@ -52,9 +52,9 @@ char *careadlinkat (int fd, char const *filename, ssize_t (*preadlinkat) (int, char const *, char *, size_t)); -/* Suitable values for careadlinkat's FD and PREADLINKAT arguments, +/* Suitable value for careadlinkat's FD argument, when doing a plain readlink: - Pass FD = AT_FDCWD and PREADLINKAT = careadlinkatcwd. */ + Pass FD = AT_FDCWD. */ #if HAVE_READLINKAT /* AT_FDCWD is declared in <fcntl.h>. */ #else @@ -66,7 +66,5 @@ char *careadlinkat (int fd, char const *filename, # define AT_FDCWD (-3041965) # endif #endif -ssize_t careadlinkatcwd (int fd, char const *filename, - char *buffer, size_t buffer_size); #endif /* _GL_CAREADLINKAT_H */ diff --git a/lib/dirent.in.h b/lib/dirent.in.h new file mode 100644 index 00000000000..fad3797b8ba --- /dev/null +++ b/lib/dirent.in.h @@ -0,0 +1,258 @@ +/* A GNU-like <dirent.h>. + Copyright (C) 2006-2013 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 <http://www.gnu.org/licenses/>. */ + +#ifndef _@GUARD_PREFIX@_DIRENT_H + +#if __GNUC__ >= 3 +@PRAGMA_SYSTEM_HEADER@ +#endif +@PRAGMA_COLUMNS@ + +/* The include_next requires a split double-inclusion guard. */ +#if @HAVE_DIRENT_H@ +# @INCLUDE_NEXT@ @NEXT_DIRENT_H@ +#endif + +#ifndef _@GUARD_PREFIX@_DIRENT_H +#define _@GUARD_PREFIX@_DIRENT_H + +/* Get ino_t. Needed on some systems, including glibc 2.8. */ +#include <sys/types.h> + +#if !@HAVE_DIRENT_H@ +/* Define types DIR and 'struct dirent'. */ +# if !GNULIB_defined_struct_dirent +struct dirent +{ + char d_type; + char d_name[1]; +}; +/* Possible values for 'd_type'. */ +# define DT_UNKNOWN 0 +# define DT_FIFO 1 /* FIFO */ +# define DT_CHR 2 /* character device */ +# define DT_DIR 4 /* directory */ +# define DT_BLK 6 /* block device */ +# define DT_REG 8 /* regular file */ +# define DT_LNK 10 /* symbolic link */ +# define DT_SOCK 12 /* socket */ +# define DT_WHT 14 /* whiteout */ +typedef struct gl_directory DIR; +# define GNULIB_defined_struct_dirent 1 +# endif +#endif + +/* The __attribute__ feature is available in gcc versions 2.5 and later. + The attribute __pure__ was added in gcc 2.96. */ +#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96) +# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +#else +# define _GL_ATTRIBUTE_PURE /* empty */ +#endif + +/* The definitions of _GL_FUNCDECL_RPL etc. are copied here. */ + +/* The definition of _GL_ARG_NONNULL is copied here. */ + +/* The definition of _GL_WARN_ON_USE is copied here. */ + + +/* Declare overridden functions. */ + +#if @GNULIB_OPENDIR@ +# if @REPLACE_OPENDIR@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef opendir +# define opendir rpl_opendir +# endif +_GL_FUNCDECL_RPL (opendir, DIR *, (const char *dir_name) _GL_ARG_NONNULL ((1))); +_GL_CXXALIAS_RPL (opendir, DIR *, (const char *dir_name)); +# else +# if !@HAVE_OPENDIR@ +_GL_FUNCDECL_SYS (opendir, DIR *, (const char *dir_name) _GL_ARG_NONNULL ((1))); +# endif +_GL_CXXALIAS_SYS (opendir, DIR *, (const char *dir_name)); +# endif +_GL_CXXALIASWARN (opendir); +#elif defined GNULIB_POSIXCHECK +# undef opendir +# if HAVE_RAW_DECL_OPENDIR +_GL_WARN_ON_USE (opendir, "opendir is not portable - " + "use gnulib module opendir for portability"); +# endif +#endif + +#if @GNULIB_READDIR@ +# if !@HAVE_READDIR@ +_GL_FUNCDECL_SYS (readdir, struct dirent *, (DIR *dirp) _GL_ARG_NONNULL ((1))); +# endif +_GL_CXXALIAS_SYS (readdir, struct dirent *, (DIR *dirp)); +_GL_CXXALIASWARN (readdir); +#elif defined GNULIB_POSIXCHECK +# undef readdir +# if HAVE_RAW_DECL_READDIR +_GL_WARN_ON_USE (readdir, "readdir is not portable - " + "use gnulib module readdir for portability"); +# endif +#endif + +#if @GNULIB_REWINDDIR@ +# if !@HAVE_REWINDDIR@ +_GL_FUNCDECL_SYS (rewinddir, void, (DIR *dirp) _GL_ARG_NONNULL ((1))); +# endif +_GL_CXXALIAS_SYS (rewinddir, void, (DIR *dirp)); +_GL_CXXALIASWARN (rewinddir); +#elif defined GNULIB_POSIXCHECK +# undef rewinddir +# if HAVE_RAW_DECL_REWINDDIR +_GL_WARN_ON_USE (rewinddir, "rewinddir is not portable - " + "use gnulib module rewinddir for portability"); +# endif +#endif + +#if @GNULIB_CLOSEDIR@ +# if @REPLACE_CLOSEDIR@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef closedir +# define closedir rpl_closedir +# endif +_GL_FUNCDECL_RPL (closedir, int, (DIR *dirp) _GL_ARG_NONNULL ((1))); +_GL_CXXALIAS_RPL (closedir, int, (DIR *dirp)); +# else +# if !@HAVE_CLOSEDIR@ +_GL_FUNCDECL_SYS (closedir, int, (DIR *dirp) _GL_ARG_NONNULL ((1))); +# endif +_GL_CXXALIAS_SYS (closedir, int, (DIR *dirp)); +# endif +_GL_CXXALIASWARN (closedir); +#elif defined GNULIB_POSIXCHECK +# undef closedir +# if HAVE_RAW_DECL_CLOSEDIR +_GL_WARN_ON_USE (closedir, "closedir is not portable - " + "use gnulib module closedir for portability"); +# endif +#endif + +#if @GNULIB_DIRFD@ +/* Return the file descriptor associated with the given directory stream, + or -1 if none exists. */ +# if @REPLACE_DIRFD@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef dirfd +# define dirfd rpl_dirfd +# endif +_GL_FUNCDECL_RPL (dirfd, int, (DIR *) _GL_ARG_NONNULL ((1))); +_GL_CXXALIAS_RPL (dirfd, int, (DIR *)); +# else +# if defined __cplusplus && defined GNULIB_NAMESPACE && defined dirfd + /* dirfd is defined as a macro and not as a function. + Turn it into a function and get rid of the macro. */ +static inline int (dirfd) (DIR *dp) { return dirfd (dp); } +# undef dirfd +# endif +# if !(@HAVE_DECL_DIRFD@ || defined dirfd) +_GL_FUNCDECL_SYS (dirfd, int, (DIR *) _GL_ARG_NONNULL ((1))); +# endif +_GL_CXXALIAS_SYS (dirfd, int, (DIR *)); +# endif +_GL_CXXALIASWARN (dirfd); +#elif defined GNULIB_POSIXCHECK +# undef dirfd +# if HAVE_RAW_DECL_DIRFD +_GL_WARN_ON_USE (dirfd, "dirfd is unportable - " + "use gnulib module dirfd for portability"); +# endif +#endif + +#if @GNULIB_FDOPENDIR@ +/* Open a directory stream visiting the given directory file + descriptor. Return NULL and set errno if fd is not visiting a + directory. On success, this function consumes fd (it will be + implicitly closed either by this function or by a subsequent + closedir). */ +# if @REPLACE_FDOPENDIR@ +# if !(defined __cplusplus && defined GNULIB_NAMESPACE) +# undef fdopendir +# define fdopendir rpl_fdopendir +# endif +_GL_FUNCDECL_RPL (fdopendir, DIR *, (int fd)); +_GL_CXXALIAS_RPL (fdopendir, DIR *, (int fd)); +# else +# if !@HAVE_FDOPENDIR@ || !@HAVE_DECL_FDOPENDIR@ +_GL_FUNCDECL_SYS (fdopendir, DIR *, (int fd)); +# endif +_GL_CXXALIAS_SYS (fdopendir, DIR *, (int fd)); +# endif +_GL_CXXALIASWARN (fdopendir); +#elif defined GNULIB_POSIXCHECK +# undef fdopendir +# if HAVE_RAW_DECL_FDOPENDIR +_GL_WARN_ON_USE (fdopendir, "fdopendir is unportable - " + "use gnulib module fdopendir for portability"); +# endif +#endif + +#if @GNULIB_SCANDIR@ +/* Scan the directory DIR, calling FILTER on each directory entry. + Entries for which FILTER returns nonzero are individually malloc'd, + sorted using qsort with CMP, and collected in a malloc'd array in + *NAMELIST. Returns the number of entries selected, or -1 on error. */ +# if !@HAVE_SCANDIR@ +_GL_FUNCDECL_SYS (scandir, int, + (const char *dir, struct dirent ***namelist, + int (*filter) (const struct dirent *), + int (*cmp) (const struct dirent **, const struct dirent **)) + _GL_ARG_NONNULL ((1, 2, 4))); +# endif +/* Need to cast, because on glibc systems, the fourth parameter is + int (*cmp) (const void *, const void *). */ +_GL_CXXALIAS_SYS_CAST (scandir, int, + (const char *dir, struct dirent ***namelist, + int (*filter) (const struct dirent *), + int (*cmp) (const struct dirent **, const struct dirent **))); +_GL_CXXALIASWARN (scandir); +#elif defined GNULIB_POSIXCHECK +# undef scandir +# if HAVE_RAW_DECL_SCANDIR +_GL_WARN_ON_USE (scandir, "scandir is unportable - " + "use gnulib module scandir for portability"); +# endif +#endif + +#if @GNULIB_ALPHASORT@ +/* Compare two 'struct dirent' entries alphabetically. */ +# if !@HAVE_ALPHASORT@ +_GL_FUNCDECL_SYS (alphasort, int, + (const struct dirent **, const struct dirent **) + _GL_ATTRIBUTE_PURE + _GL_ARG_NONNULL ((1, 2))); +# endif +/* Need to cast, because on glibc systems, the parameters are + (const void *, const void *). */ +_GL_CXXALIAS_SYS_CAST (alphasort, int, + (const struct dirent **, const struct dirent **)); +_GL_CXXALIASWARN (alphasort); +#elif defined GNULIB_POSIXCHECK +# undef alphasort +# if HAVE_RAW_DECL_ALPHASORT +_GL_WARN_ON_USE (alphasort, "alphasort is unportable - " + "use gnulib module alphasort for portability"); +# endif +#endif + + +#endif /* _@GUARD_PREFIX@_DIRENT_H */ +#endif /* _@GUARD_PREFIX@_DIRENT_H */ diff --git a/lib/fdopendir.c b/lib/fdopendir.c new file mode 100644 index 00000000000..63e06b92ae8 --- /dev/null +++ b/lib/fdopendir.c @@ -0,0 +1,204 @@ +/* provide a replacement fdopendir function + Copyright (C) 2004-2013 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 <http://www.gnu.org/licenses/>. */ + +/* written by Jim Meyering */ + +#include <config.h> + +#include <dirent.h> + +#include <stdlib.h> +#include <unistd.h> + +#if !HAVE_FDOPENDIR + +# include "openat.h" +# include "openat-priv.h" +# include "save-cwd.h" + +# if GNULIB_DIRENT_SAFER +# include "dirent--.h" +# endif + +# ifndef REPLACE_FCHDIR +# define REPLACE_FCHDIR 0 +# endif + +static DIR *fdopendir_with_dup (int, int, struct saved_cwd const *); +static DIR *fd_clone_opendir (int, struct saved_cwd const *); + +/* Replacement for POSIX fdopendir. + + First, try to simulate it via opendir ("/proc/self/fd/..."). Failing + that, simulate it by using fchdir metadata, or by doing + save_cwd/fchdir/opendir(".")/restore_cwd. + If either the save_cwd or the restore_cwd fails (relatively unlikely), + then give a diagnostic and exit nonzero. + + If successful, the resulting stream is based on FD in + implementations where streams are based on file descriptors and in + applications where no other thread or signal handler allocates or + frees file descriptors. In other cases, consult dirfd on the result + to find out whether FD is still being used. + + Otherwise, this function works just like POSIX fdopendir. + + W A R N I N G: + + Unlike other fd-related functions, this one places constraints on FD. + If this function returns successfully, FD is under control of the + dirent.h system, and the caller should not close or modify the state of + FD other than by the dirent.h functions. */ +DIR * +fdopendir (int fd) +{ + DIR *dir = fdopendir_with_dup (fd, -1, NULL); + + if (! REPLACE_FCHDIR && ! dir) + { + int saved_errno = errno; + if (EXPECTED_ERRNO (saved_errno)) + { + struct saved_cwd cwd; + if (save_cwd (&cwd) != 0) + openat_save_fail (errno); + dir = fdopendir_with_dup (fd, -1, &cwd); + saved_errno = errno; + free_cwd (&cwd); + errno = saved_errno; + } + } + + return dir; +} + +/* Like fdopendir, except that if OLDER_DUPFD is not -1, it is known + to be a dup of FD which is less than FD - 1 and which will be + closed by the caller and not otherwise used by the caller. This + function makes sure that FD is closed and all file descriptors less + than FD are open, and then calls fd_clone_opendir on a dup of FD. + That way, barring race conditions, fd_clone_opendir returns a + stream whose file descriptor is FD. + + If REPLACE_CHDIR or CWD is null, use opendir ("/proc/self/fd/...", + falling back on fchdir metadata. Otherwise, CWD is a saved version + of the working directory; use fchdir/opendir(".")/restore_cwd(CWD). */ +static DIR * +fdopendir_with_dup (int fd, int older_dupfd, struct saved_cwd const *cwd) +{ + int dupfd = dup (fd); + if (dupfd < 0 && errno == EMFILE) + dupfd = older_dupfd; + if (dupfd < 0) + return NULL; + else + { + DIR *dir; + int saved_errno; + if (dupfd < fd - 1 && dupfd != older_dupfd) + { + dir = fdopendir_with_dup (fd, dupfd, cwd); + saved_errno = errno; + } + else + { + close (fd); + dir = fd_clone_opendir (dupfd, cwd); + saved_errno = errno; + if (! dir) + { + int fd1 = dup (dupfd); + if (fd1 != fd) + openat_save_fail (fd1 < 0 ? errno : EBADF); + } + } + + if (dupfd != older_dupfd) + close (dupfd); + errno = saved_errno; + return dir; + } +} + +/* Like fdopendir, except the result controls a clone of FD. It is + the caller's responsibility both to close FD and (if the result is + not null) to closedir the result. */ +static DIR * +fd_clone_opendir (int fd, struct saved_cwd const *cwd) +{ + if (REPLACE_FCHDIR || ! cwd) + { + DIR *dir = NULL; + int saved_errno = EOPNOTSUPP; + char buf[OPENAT_BUFFER_SIZE]; + char *proc_file = openat_proc_name (buf, fd, "."); + if (proc_file) + { + dir = opendir (proc_file); + saved_errno = errno; + if (proc_file != buf) + free (proc_file); + } +# if REPLACE_FCHDIR + if (! dir && EXPECTED_ERRNO (saved_errno)) + { + char const *name = _gl_directory_name (fd); + return (name ? opendir (name) : NULL); + } +# endif + errno = saved_errno; + return dir; + } + else + { + if (fchdir (fd) != 0) + return NULL; + else + { + DIR *dir = opendir ("."); + int saved_errno = errno; + if (restore_cwd (cwd) != 0) + openat_restore_fail (errno); + errno = saved_errno; + return dir; + } + } +} + +#else /* HAVE_FDOPENDIR */ + +# include <errno.h> +# include <sys/stat.h> + +# undef fdopendir + +/* Like fdopendir, but work around GNU/Hurd bug by validating FD. */ + +DIR * +rpl_fdopendir (int fd) +{ + struct stat st; + if (fstat (fd, &st)) + return NULL; + if (!S_ISDIR (st.st_mode)) + { + errno = ENOTDIR; + return NULL; + } + return fdopendir (fd); +} + +#endif /* HAVE_FDOPENDIR */ diff --git a/lib/fstatat.c b/lib/fstatat.c new file mode 100644 index 00000000000..845c171fb45 --- /dev/null +++ b/lib/fstatat.c @@ -0,0 +1,135 @@ +/* Work around an fstatat bug on Solaris 9. + + Copyright (C) 2006, 2009-2013 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 <http://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert and 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_fstatat doesn't recurse to + rpl_fstatat. */ +#define __need_system_sys_stat_h +#include <config.h> + +/* Get the original definition of fstatat. It might be defined as a macro. */ +#include <sys/types.h> +#include <sys/stat.h> +#undef __need_system_sys_stat_h + +#if HAVE_FSTATAT +static int +orig_fstatat (int fd, char const *filename, struct stat *buf, int flags) +{ + return fstatat (fd, filename, buf, flags); +} +#endif + +/* 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" + +#include <errno.h> +#include <fcntl.h> +#include <string.h> + +#if HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG + +# ifndef LSTAT_FOLLOWS_SLASHED_SYMLINK +# define LSTAT_FOLLOWS_SLASHED_SYMLINK 0 +# endif + +/* fstatat should always follow symbolic links that end in /, but on + Solaris 9 it doesn't if AT_SYMLINK_NOFOLLOW is specified. + Likewise, trailing slash on a non-directory should be an error. + These are the same problems that lstat.c and stat.c address, so + solve it in a similar way. + + AIX 7.1 fstatat (AT_FDCWD, ..., 0) always fails, which is a bug. + Work around this bug if FSTATAT_AT_FDCWD_0_BROKEN is nonzero. */ + +int +rpl_fstatat (int fd, char const *file, struct stat *st, int flag) +{ + int result = orig_fstatat (fd, file, st, flag); + size_t len; + + if (LSTAT_FOLLOWS_SLASHED_SYMLINK || result != 0) + return result; + len = strlen (file); + if (flag & AT_SYMLINK_NOFOLLOW) + { + /* Fix lstat behavior. */ + if (file[len - 1] != '/' || S_ISDIR (st->st_mode)) + return 0; + if (!S_ISLNK (st->st_mode)) + { + errno = ENOTDIR; + return -1; + } + result = orig_fstatat (fd, file, st, flag & ~AT_SYMLINK_NOFOLLOW); + } + /* Fix stat behavior. */ + if (result == 0 && !S_ISDIR (st->st_mode) && file[len - 1] == '/') + { + errno = ENOTDIR; + return -1; + } + return result; +} + +#else /* ! (HAVE_FSTATAT && HAVE_WORKING_FSTATAT_ZERO_FLAG) */ + +/* On mingw, the gnulib <sys/stat.h> defines 'stat' as a function-like + macro; but using it in AT_FUNC_F2 causes compilation failure + because the preprocessor sees a use of a macro that requires two + arguments but is only given one. Hence, we need an inline + forwarder to get past the preprocessor. */ +static int +stat_func (char const *name, struct stat *st) +{ + return stat (name, st); +} + +/* Likewise, if there is no native 'lstat', then the gnulib + <sys/stat.h> defined it as stat, which also needs adjustment. */ +# if !HAVE_LSTAT +# undef lstat +# define lstat stat_func +# endif + +/* Replacement for Solaris' function by the same name. + <http://www.google.com/search?q=fstatat+site:docs.sun.com> + First, try to simulate it via l?stat ("/proc/self/fd/FD/FILE"). + Failing that, simulate it via save_cwd/fchdir/(stat|lstat)/restore_cwd. + If either the save_cwd or the restore_cwd fails (relatively unlikely), + then give a diagnostic and exit nonzero. + Otherwise, this function works just like Solaris' fstatat. */ + +# define AT_FUNC_NAME fstatat +# define AT_FUNC_F1 lstat +# define AT_FUNC_F2 stat_func +# define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW +# define AT_FUNC_POST_FILE_PARAM_DECLS , struct stat *st, int flag +# define AT_FUNC_POST_FILE_ARGS , st +# include "at-func.c" +# undef AT_FUNC_NAME +# undef AT_FUNC_F1 +# undef AT_FUNC_F2 +# undef AT_FUNC_USE_F1_COND +# undef AT_FUNC_POST_FILE_PARAM_DECLS +# undef AT_FUNC_POST_FILE_ARGS + +#endif /* !HAVE_FSTATAT */ diff --git a/lib/gnulib.mk b/lib/gnulib.mk index 2347d84448d..89317fd2088 100644 --- a/lib/gnulib.mk +++ b/lib/gnulib.mk @@ -21,7 +21,7 @@ # the same distribution terms as the rest of that program. # # Generated by gnulib-tool. -# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=at-internal --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=openat-die --avoid=openat-h --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl-h filemode getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask putenv readlink sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings +# Reproduce by: gnulib-tool --import --dir=. --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --avoid=dup --avoid=errno --avoid=fchdir --avoid=fcntl --avoid=fstat --avoid=malloc-posix --avoid=msvc-inval --avoid=msvc-nothrow --avoid=open --avoid=openat-die --avoid=opendir --avoid=raise --avoid=save-cwd --avoid=select --avoid=sigprocmask --avoid=sys_types --avoid=threadlib --makefile-name=gnulib.mk --conditional-dependencies --no-libtool --macro-prefix=gl --no-vc-files alloca-opt c-ctype c-strcase careadlinkat close-stream crypto/md5 crypto/sha1 crypto/sha256 crypto/sha512 dtoastr dtotimespec dup2 environ execinfo faccessat fcntl-h fdopendir filemode fstatat getloadavg getopt-gnu gettime gettimeofday ignore-value intprops largefile lstat manywarnings mktime pselect pthread_sigmask putenv readlink readlinkat sig2str socklen stat-time stdalign stdarg stdbool stdio strftime strtoimax strtoumax symlink sys_stat sys_time time timer-time timespec-add timespec-sub unsetenv utimens warnings MOSTLYCLEANFILES += core *.stackdump @@ -64,6 +64,17 @@ EXTRA_DIST += allocator.h ## end gnulib module allocator +## begin gnulib module at-internal + +if gl_GNULIB_ENABLED_260941c0e5dc67ec9e87d1fb321c300b + +endif +EXTRA_DIST += openat-priv.h openat-proc.c + +EXTRA_libgnu_a_SOURCES += openat-proc.c + +## end gnulib module at-internal + ## begin gnulib module c-ctype libgnu_a_SOURCES += c-ctype.h c-ctype.c @@ -124,6 +135,54 @@ EXTRA_DIST += sha512.h ## end gnulib module crypto/sha512 +## begin gnulib module dirent + +BUILT_SOURCES += dirent.h + +# We need the following in order to create <dirent.h> when the system +# doesn't have one that works with the given compiler. +dirent.h: dirent.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(WARN_ON_USE_H) + $(AM_V_GEN)rm -f $@-t $@ && \ + { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \ + sed -e 's|@''GUARD_PREFIX''@|GL|g' \ + -e 's|@''HAVE_DIRENT_H''@|$(HAVE_DIRENT_H)|g' \ + -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \ + -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \ + -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \ + -e 's|@''NEXT_DIRENT_H''@|$(NEXT_DIRENT_H)|g' \ + -e 's/@''GNULIB_OPENDIR''@/$(GNULIB_OPENDIR)/g' \ + -e 's/@''GNULIB_READDIR''@/$(GNULIB_READDIR)/g' \ + -e 's/@''GNULIB_REWINDDIR''@/$(GNULIB_REWINDDIR)/g' \ + -e 's/@''GNULIB_CLOSEDIR''@/$(GNULIB_CLOSEDIR)/g' \ + -e 's/@''GNULIB_DIRFD''@/$(GNULIB_DIRFD)/g' \ + -e 's/@''GNULIB_FDOPENDIR''@/$(GNULIB_FDOPENDIR)/g' \ + -e 's/@''GNULIB_SCANDIR''@/$(GNULIB_SCANDIR)/g' \ + -e 's/@''GNULIB_ALPHASORT''@/$(GNULIB_ALPHASORT)/g' \ + -e 's/@''HAVE_OPENDIR''@/$(HAVE_OPENDIR)/g' \ + -e 's/@''HAVE_READDIR''@/$(HAVE_READDIR)/g' \ + -e 's/@''HAVE_REWINDDIR''@/$(HAVE_REWINDDIR)/g' \ + -e 's/@''HAVE_CLOSEDIR''@/$(HAVE_CLOSEDIR)/g' \ + -e 's|@''HAVE_DECL_DIRFD''@|$(HAVE_DECL_DIRFD)|g' \ + -e 's|@''HAVE_DECL_FDOPENDIR''@|$(HAVE_DECL_FDOPENDIR)|g' \ + -e 's|@''HAVE_FDOPENDIR''@|$(HAVE_FDOPENDIR)|g' \ + -e 's|@''HAVE_SCANDIR''@|$(HAVE_SCANDIR)|g' \ + -e 's|@''HAVE_ALPHASORT''@|$(HAVE_ALPHASORT)|g' \ + -e 's|@''REPLACE_OPENDIR''@|$(REPLACE_OPENDIR)|g' \ + -e 's|@''REPLACE_CLOSEDIR''@|$(REPLACE_CLOSEDIR)|g' \ + -e 's|@''REPLACE_DIRFD''@|$(REPLACE_DIRFD)|g' \ + -e 's|@''REPLACE_FDOPENDIR''@|$(REPLACE_FDOPENDIR)|g' \ + -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \ + -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \ + -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \ + < $(srcdir)/dirent.in.h; \ + } > $@-t && \ + mv $@-t $@ +MOSTLYCLEANFILES += dirent.h dirent.h-t + +EXTRA_DIST += dirent.in.h + +## end gnulib module dirent + ## begin gnulib module dosname if gl_GNULIB_ENABLED_dosname @@ -238,6 +297,15 @@ EXTRA_DIST += fcntl.in.h ## end gnulib module fcntl-h +## begin gnulib module fdopendir + + +EXTRA_DIST += fdopendir.c + +EXTRA_libgnu_a_SOURCES += fdopendir.c + +## end gnulib module fdopendir + ## begin gnulib module filemode libgnu_a_SOURCES += filemode.c @@ -255,6 +323,15 @@ EXTRA_libgnu_a_SOURCES += fpending.c ## end gnulib module fpending +## begin gnulib module fstatat + + +EXTRA_DIST += at-func.c fstatat.c + +EXTRA_libgnu_a_SOURCES += at-func.c fstatat.c + +## end gnulib module fstatat + ## begin gnulib module getgroups if gl_GNULIB_ENABLED_getgroups @@ -412,6 +489,15 @@ EXTRA_libgnu_a_SOURCES += mktime.c ## end gnulib module mktime +## begin gnulib module openat-h + +if gl_GNULIB_ENABLED_03e0aaad4cb89ca757653bd367a6ccb7 + +endif +EXTRA_DIST += openat.h + +## end gnulib module openat-h + ## begin gnulib module pathmax if gl_GNULIB_ENABLED_pathmax @@ -457,6 +543,15 @@ EXTRA_libgnu_a_SOURCES += readlink.c ## end gnulib module readlink +## begin gnulib module readlinkat + + +EXTRA_DIST += at-func.c readlinkat.c + +EXTRA_libgnu_a_SOURCES += at-func.c readlinkat.c + +## end gnulib module readlinkat + ## begin gnulib module root-uid if gl_GNULIB_ENABLED_6099e9737f757db36c47fa9d9f02e88c diff --git a/lib/openat-die.c b/lib/openat-die.c new file mode 100644 index 00000000000..f09123ea785 --- /dev/null +++ b/lib/openat-die.c @@ -0,0 +1,6 @@ +/* Respond to a save- or restore-cwd failure. + This should never happen with Emacs. */ +#include <config.h> +#include "openat.h" +void openat_save_fail (int errnum) { abort (); } +void openat_restore_fail (int errnum) { abort (); } diff --git a/lib/openat-priv.h b/lib/openat-priv.h new file mode 100644 index 00000000000..829cf7d0855 --- /dev/null +++ b/lib/openat-priv.h @@ -0,0 +1,64 @@ +/* Internals for openat-like functions. + + Copyright (C) 2005-2006, 2009-2013 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 <http://www.gnu.org/licenses/>. */ + +/* written by Jim Meyering */ + +#ifndef _GL_HEADER_OPENAT_PRIV +#define _GL_HEADER_OPENAT_PRIV + +#include <errno.h> +#include <limits.h> +#include <stdlib.h> + +/* Maximum number of bytes that it is safe to allocate as a single + array on the stack, and that is known as a compile-time constant. + The assumption is that we'll touch the array very quickly, or a + temporary very near the array, provoking an out-of-memory trap. On + some operating systems, there is only one guard page for the stack, + and a page size can be as small as 4096 bytes. Subtract 64 in the + hope that this will let the compiler touch a nearby temporary and + provoke a trap. */ +#define SAFER_ALLOCA_MAX (4096 - 64) + +#define SAFER_ALLOCA(m) ((m) < SAFER_ALLOCA_MAX ? (m) : SAFER_ALLOCA_MAX) + +#if defined PATH_MAX +# define OPENAT_BUFFER_SIZE SAFER_ALLOCA (PATH_MAX) +#elif defined _XOPEN_PATH_MAX +# define OPENAT_BUFFER_SIZE SAFER_ALLOCA (_XOPEN_PATH_MAX) +#else +# define OPENAT_BUFFER_SIZE SAFER_ALLOCA (1024) +#endif + +char *openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file); + +/* Trying to access a BUILD_PROC_NAME file will fail on systems without + /proc support, and even on systems *with* ProcFS support. Return + nonzero if the failure may be legitimate, e.g., because /proc is not + readable, or the particular .../fd/N directory is not present. */ +#define EXPECTED_ERRNO(Errno) \ + ((Errno) == ENOTDIR || (Errno) == ENOENT \ + || (Errno) == EPERM || (Errno) == EACCES \ + || (Errno) == ENOSYS /* Solaris 8 */ \ + || (Errno) == EOPNOTSUPP /* FreeBSD */) + +/* Wrapper function shared among linkat and renameat. */ +int at_func2 (int fd1, char const *file1, + int fd2, char const *file2, + int (*func) (char const *file1, char const *file2)); + +#endif /* _GL_HEADER_OPENAT_PRIV */ diff --git a/lib/openat-proc.c b/lib/openat-proc.c new file mode 100644 index 00000000000..d7a68e26d0b --- /dev/null +++ b/lib/openat-proc.c @@ -0,0 +1,110 @@ +/* Create /proc/self/fd-related names for subfiles of open directories. + + Copyright (C) 2006, 2009-2013 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 <http://www.gnu.org/licenses/>. */ + +/* Written by Paul Eggert. */ + +#include <config.h> + +#include "openat-priv.h" + +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "intprops.h" + +/* The results of open() in this file are not used with fchdir, + and we do not leak fds to any single-threaded code that could use stdio, + therefore save some unnecessary work in fchdir.c. + FIXME - if the kernel ever adds support for multi-thread safety for + avoiding standard fds, then we should use open_safer. */ +#undef open +#undef close + +#define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/%s" + +#define PROC_SELF_FD_NAME_SIZE_BOUND(len) \ + (sizeof PROC_SELF_FD_FORMAT - sizeof "%d%s" \ + + INT_STRLEN_BOUND (int) + (len) + 1) + + +/* Set BUF to the expansion of PROC_SELF_FD_FORMAT, using FD and FILE + respectively for %d and %s. If successful, return BUF if the + result fits in BUF, dynamically allocated memory otherwise. But + return NULL if /proc is not reliable, either because the operating + system support is lacking or because memory is low. */ +char * +openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file) +{ + static int proc_status = 0; + + /* Make sure the caller gets ENOENT when appropriate. */ + if (!*file) + { + buf[0] = '\0'; + return buf; + } + + if (! proc_status) + { + /* Set PROC_STATUS to a positive value if /proc/self/fd is + reliable, and a negative value otherwise. Solaris 10 + /proc/self/fd mishandles "..", and any file name might expand + to ".." after symbolic link expansion, so avoid /proc/self/fd + if it mishandles "..". Solaris 10 has openat, but this + problem is exhibited on code that built on Solaris 8 and + running on Solaris 10. */ + + int proc_self_fd = open ("/proc/self/fd", + O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NONBLOCK); + if (proc_self_fd < 0) + proc_status = -1; + else + { + /* Detect whether /proc/self/fd/%i/../fd exists, where %i is the + number of a file descriptor open on /proc/self/fd. On Linux, + that name resolves to /proc/self/fd, which was opened above. + However, on Solaris, it may resolve to /proc/self/fd/fd, which + cannot exist, since all names in /proc/self/fd are numeric. */ + char dotdot_buf[PROC_SELF_FD_NAME_SIZE_BOUND (sizeof "../fd" - 1)]; + sprintf (dotdot_buf, PROC_SELF_FD_FORMAT, proc_self_fd, "../fd"); + proc_status = access (dotdot_buf, F_OK) ? -1 : 1; + close (proc_self_fd); + } + } + + if (proc_status < 0) + return NULL; + else + { + size_t bufsize = PROC_SELF_FD_NAME_SIZE_BOUND (strlen (file)); + char *result = buf; + if (OPENAT_BUFFER_SIZE < bufsize) + { + result = malloc (bufsize); + if (! result) + return NULL; + } + sprintf (result, PROC_SELF_FD_FORMAT, fd, file); + return result; + } +} diff --git a/lib/openat.h b/lib/openat.h new file mode 100644 index 00000000000..eb90990da1d --- /dev/null +++ b/lib/openat.h @@ -0,0 +1,120 @@ +/* provide a replacement openat function + Copyright (C) 2004-2006, 2008-2013 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 <http://www.gnu.org/licenses/>. */ + +/* written by Jim Meyering */ + +#ifndef _GL_HEADER_OPENAT +#define _GL_HEADER_OPENAT + +#include <fcntl.h> + +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <stdbool.h> + +_GL_INLINE_HEADER_BEGIN + +#if !HAVE_OPENAT + +int openat_permissive (int fd, char const *file, int flags, mode_t mode, + int *cwd_errno); +bool openat_needs_fchdir (void); + +#else + +# define openat_permissive(Fd, File, Flags, Mode, Cwd_errno) \ + openat (Fd, File, Flags, Mode) +# define openat_needs_fchdir() false + +#endif + +_Noreturn void openat_restore_fail (int); +_Noreturn void openat_save_fail (int); + +/* Using these function names makes application code + slightly more readable than it would be with + fchownat (..., 0) or fchownat (..., AT_SYMLINK_NOFOLLOW). */ + +#if GNULIB_FCHOWNAT + +# ifndef FCHOWNAT_INLINE +# define FCHOWNAT_INLINE _GL_INLINE +# endif + +FCHOWNAT_INLINE int +chownat (int fd, char const *file, uid_t owner, gid_t group) +{ + return fchownat (fd, file, owner, group, 0); +} + +FCHOWNAT_INLINE int +lchownat (int fd, char const *file, uid_t owner, gid_t group) +{ + return fchownat (fd, file, owner, group, AT_SYMLINK_NOFOLLOW); +} + +#endif + +#if GNULIB_FCHMODAT + +# ifndef FCHMODAT_INLINE +# define FCHMODAT_INLINE _GL_INLINE +# endif + +FCHMODAT_INLINE int +chmodat (int fd, char const *file, mode_t mode) +{ + return fchmodat (fd, file, mode, 0); +} + +FCHMODAT_INLINE int +lchmodat (int fd, char const *file, mode_t mode) +{ + return fchmodat (fd, file, mode, AT_SYMLINK_NOFOLLOW); +} + +#endif + +#if GNULIB_STATAT + +# ifndef STATAT_INLINE +# define STATAT_INLINE _GL_INLINE +# endif + +STATAT_INLINE int +statat (int fd, char const *name, struct stat *st) +{ + return fstatat (fd, name, st, 0); +} + +STATAT_INLINE int +lstatat (int fd, char const *name, struct stat *st) +{ + return fstatat (fd, name, st, AT_SYMLINK_NOFOLLOW); +} + +#endif + +/* For now, there are no wrappers named laccessat or leuidaccessat, + since gnulib doesn't support faccessat(,AT_SYMLINK_NOFOLLOW) and + since access rights on symlinks are of limited utility. Likewise, + wrappers are not provided for accessat or euidaccessat, so as to + avoid dragging in -lgen on some platforms. */ + +_GL_INLINE_HEADER_END + +#endif /* _GL_HEADER_OPENAT */ diff --git a/lib/readlinkat.c b/lib/readlinkat.c new file mode 100644 index 00000000000..504e6ebbc49 --- /dev/null +++ b/lib/readlinkat.c @@ -0,0 +1,47 @@ +/* Read a symlink relative to an open directory. + Copyright (C) 2009-2013 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 <http://www.gnu.org/licenses/>. */ + +/* written by Eric Blake */ + +#include <config.h> + +#include <unistd.h> + +/* Gnulib provides a readlink stub for mingw; use it for distinction + between EINVAL and ENOENT, rather than always failing with ENOSYS. */ + +/* POSIX 2008 says that unlike readlink, readlinkat returns 0 for + success instead of the buffer length. But this would render + readlinkat worthless since readlink does not guarantee a + NUL-terminated buffer. Assume this was a bug in POSIX. */ + +/* Read the contents of symlink FILE into buffer BUF of size LEN, in the + directory open on descriptor FD. If possible, do it without changing + the working directory. Otherwise, resort to using save_cwd/fchdir, + then readlink/restore_cwd. If either the save_cwd or the restore_cwd + fails, then give a diagnostic and exit nonzero. */ + +#define AT_FUNC_NAME readlinkat +#define AT_FUNC_F1 readlink +#define AT_FUNC_POST_FILE_PARAM_DECLS , char *buf, size_t len +#define AT_FUNC_POST_FILE_ARGS , buf, len +#define AT_FUNC_RESULT ssize_t +#include "at-func.c" +#undef AT_FUNC_NAME +#undef AT_FUNC_F1 +#undef AT_FUNC_POST_FILE_PARAM_DECLS +#undef AT_FUNC_POST_FILE_ARGS +#undef AT_FUNC_RESULT diff --git a/lib/save-cwd.c b/lib/save-cwd.c new file mode 100644 index 00000000000..b8dae34ca02 --- /dev/null +++ b/lib/save-cwd.c @@ -0,0 +1,3 @@ +#include <config.h> +#define SAVE_CWD_INLINE _GL_EXTERN_INLINE +#include "save-cwd.h" diff --git a/lib/save-cwd.h b/lib/save-cwd.h new file mode 100644 index 00000000000..bd0cd8d5707 --- /dev/null +++ b/lib/save-cwd.h @@ -0,0 +1,46 @@ +/* Do not save and restore the current working directory. + + Copyright 2013 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 <http://www.gnu.org/licenses/>. */ + +/* Gnulib needs to save and restore the current working directory to + fully emulate functions like fstatat. But Emacs doesn't care what + the current working directory is; it always uses absolute file + names. This module replaces the Gnulib module by omitting the code + that Emacs does not need. */ + +#ifndef SAVE_CWD_H +#define SAVE_CWD_H 1 + +_GL_INLINE_HEADER_BEGIN +#ifndef SAVE_CWD_INLINE +# define SAVE_CWD_INLINE _GL_INLINE +#endif + +struct saved_cwd { int desc; }; + +SAVE_CWD_INLINE int +save_cwd (struct saved_cwd *cwd) +{ + cwd->desc = -1; + return 0; +} + +SAVE_CWD_INLINE int restore_cwd (struct saved_cwd const *cwd) { return 0; } +SAVE_CWD_INLINE void free_cwd (struct saved_cwd *cwd) { } + +_GL_INLINE_HEADER_END + +#endif |