diff options
Diffstat (limited to 'lib/fdopendir.c')
| -rw-r--r-- | lib/fdopendir.c | 97 |
1 files changed, 61 insertions, 36 deletions
diff --git a/lib/fdopendir.c b/lib/fdopendir.c index aa841e3e81..0f43d6ff34 100644 --- a/lib/fdopendir.c +++ b/lib/fdopendir.c @@ -25,44 +25,27 @@ #if !HAVE_FDOPENDIR -# include "openat.h" -# include "openat-priv.h" -# include "save-cwd.h" +# if GNULIB_defined_DIR +/* We are in control of the file descriptor of a DIR. */ -# 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. +# include "dirent-private.h" - 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. +# if !REPLACE_FCHDIR +# error "unexpected configuration: GNULIB_defined_DIR but fchdir not replaced" +# endif - Otherwise, this function works just like POSIX fdopendir. +DIR * +fdopendir (int fd) +{ + char const *name = _gl_directory_name (fd); + DIR *dirp = name ? opendir (name) : NULL; + if (dirp != NULL) + dirp->fd_to_close = fd; + return dirp; +} - W A R N I N G: +# elif defined __KLIBC__ - 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. */ -# ifdef __KLIBC__ # include <InnoTekLIBC/backend.h> DIR * @@ -96,7 +79,48 @@ fdopendir (int fd) return dirp; } + # else +/* We are not in control of the file descriptor of a DIR, and therefore have to + play tricks with file descriptors before and after a call to opendir(). */ + +# 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) { @@ -119,7 +143,6 @@ fdopendir (int fd) return dir; } -# endif /* 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 @@ -188,7 +211,7 @@ fd_clone_opendir (int fd, struct saved_cwd const *cwd) if (proc_file != buf) free (proc_file); } -# if REPLACE_FCHDIR +# if REPLACE_FCHDIR if (! dir && EXPECTED_ERRNO (saved_errno)) { char const *name = _gl_directory_name (fd); @@ -203,7 +226,7 @@ fd_clone_opendir (int fd, struct saved_cwd const *cwd) return dp; } -# endif +# endif errno = saved_errno; return dir; } @@ -223,6 +246,8 @@ fd_clone_opendir (int fd, struct saved_cwd const *cwd) } } +# endif + #else /* HAVE_FDOPENDIR */ # include <errno.h> |