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/* -*- mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
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// vim: expandtab:ts=8:sw=4:softtabstop=4:
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///////////////////////////////////////////////////////////////////////////////
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/// \brief File opening, unlinking, and closing
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// Author: Lasse Collin
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// This file has been put into the public domain.
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// You can do whatever you want with this file.
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///////////////////////////////////////////////////////////////////////////////
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#if defined(HAVE_FUTIMES) || defined(HAVE_FUTIMESAT) || defined(HAVE_UTIMES)
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# include <sys/time.h>
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#elif defined(HAVE_UTIME)
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# include "open_stdxxx.h"
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static bool warn_fchown;
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// Make sure that stdin, stdout, and and stderr are connected to
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// a valid file descriptor. Exit immediatelly with exit code ERROR
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// if we cannot make the file descriptors valid. Maybe we should
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// print an error message, but our stderr could be screwed anyway.
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// If fchown() fails setting the owner, we warn about it only if
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warn_fchown = geteuid() == 0;
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// Avoid doing useless things when statting files.
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// This isn't important but doesn't hurt.
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_djstat_flags = _STAT_INODE | _STAT_EXEC_EXT
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| _STAT_EXEC_MAGIC | _STAT_DIRSIZE;
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/// \brief Unlinks a file
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/// This tries to verify that the file being unlinked really is the file that
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/// we want to unlink by verifying device and inode numbers. There's still
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/// a small unavoidable race, but this is much better than nothing (the file
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/// could have been moved/replaced even hours earlier).
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io_unlink(const char *name, const struct stat *known_st)
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// On Windows, st_ino is meaningless, so don't bother testing it.
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// Just silence a compiler warning.
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if (lstat(name, &new_st)
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|| new_st.st_dev != known_st->st_dev
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|| new_st.st_ino != known_st->st_ino)
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message_error(_("%s: File seems to be moved, not removing"),
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// There's a race condition between lstat() and unlink()
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// but at least we have tried to avoid removing wrong file.
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message_error(_("%s: Cannot remove: %s"),
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name, strerror(errno));
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/// \brief Copies owner/group and permissions
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/// \todo ACL and EA support
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io_copy_attrs(const file_pair *pair)
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// Skip chown and chmod on Windows.
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// This function is more tricky than you may think at first.
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// Blindly copying permissions may permit users to access the
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// destination file who didn't have permission to access the
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// Try changing the owner of the file. If we aren't root or the owner
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// isn't already us, fchown() probably doesn't succeed. We warn
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// about failing fchown() only if we are root.
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if (fchown(pair->dest_fd, pair->src_st.st_uid, -1) && warn_fchown)
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message_warning(_("%s: Cannot set the file owner: %s"),
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pair->dest_name, strerror(errno));
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if (fchown(pair->dest_fd, -1, pair->src_st.st_gid)) {
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message_warning(_("%s: Cannot set the file group: %s"),
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pair->dest_name, strerror(errno));
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// We can still safely copy some additional permissions:
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// `group' must be at least as strict as `other' and
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// NOTE: After this, the owner of the source file may
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// get additional permissions. This shouldn't be too bad,
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// because the owner would have had permission to chmod
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// the original file anyway.
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mode = ((pair->src_st.st_mode & 0070) >> 3)
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& (pair->src_st.st_mode & 0007);
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mode = (pair->src_st.st_mode & 0700) | (mode << 3) | mode;
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// Drop the setuid, setgid, and sticky bits.
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mode = pair->src_st.st_mode & 0777;
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if (fchmod(pair->dest_fd, mode))
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message_warning(_("%s: Cannot set the file permissions: %s"),
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pair->dest_name, strerror(errno));
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// Copy the timestamps. We have several possible ways to do this, of
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// which some are better in both security and precision.
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// First, get the nanosecond part of the timestamps. As of writing,
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// it's not standardized by POSIX, and there are several names for
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// the same thing in struct stat.
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# if defined(HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC)
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atime_nsec = pair->src_st.st_atim.tv_nsec;
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mtime_nsec = pair->src_st.st_mtim.tv_nsec;
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# elif defined(HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC)
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atime_nsec = pair->src_st.st_atimespec.tv_nsec;
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mtime_nsec = pair->src_st.st_mtimespec.tv_nsec;
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# elif defined(HAVE_STRUCT_STAT_ST_ATIMENSEC)
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// GNU and BSD without extensions
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atime_nsec = pair->src_st.st_atimensec;
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mtime_nsec = pair->src_st.st_mtimensec;
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# elif defined(HAVE_STRUCT_STAT_ST_UATIME)
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atime_nsec = pair->src_st.st_uatime * 1000;
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mtime_nsec = pair->src_st.st_umtime * 1000;
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# elif defined(HAVE_STRUCT_STAT_ST_ATIM_ST__TIM_TV_NSEC)
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atime_nsec = pair->src_st.st_atim.st__tim.tv_nsec;
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mtime_nsec = pair->src_st.st_mtim.st__tim.tv_nsec;
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// Construct a structure to hold the timestamps and call appropriate
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// function to set the timestamps.
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#if defined(HAVE_FUTIMENS)
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// Use nanosecond precision.
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struct timespec tv[2];
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tv[0].tv_sec = pair->src_st.st_atime;
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tv[0].tv_nsec = atime_nsec;
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tv[1].tv_sec = pair->src_st.st_mtime;
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tv[1].tv_nsec = mtime_nsec;
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(void)futimens(pair->dest_fd, tv);
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#elif defined(HAVE_FUTIMES) || defined(HAVE_FUTIMESAT) || defined(HAVE_UTIMES)
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// Use microsecond precision.
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struct timeval tv[2];
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tv[0].tv_sec = pair->src_st.st_atime;
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tv[0].tv_usec = atime_nsec / 1000;
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tv[1].tv_sec = pair->src_st.st_mtime;
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tv[1].tv_usec = mtime_nsec / 1000;
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# if defined(HAVE_FUTIMES)
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(void)futimes(pair->dest_fd, tv);
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# elif defined(HAVE_FUTIMESAT)
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(void)futimesat(pair->dest_fd, NULL, tv);
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// Argh, no function to use a file descriptor to set the timestamp.
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(void)utimes(pair->dest_name, tv);
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#elif defined(HAVE_UTIME)
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// Use one-second precision. utime() doesn't support using file
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// descriptor either. Some systems have broken utime() prototype
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// so don't make this const.
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struct utimbuf buf = {
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.actime = pair->src_st.st_atime,
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.modtime = pair->src_st.st_mtime,
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(void)utime(pair->dest_name, &buf);
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/// Opens the source file. Returns false on success, true on error.
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io_open_src(file_pair *pair)
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// There's nothing to open when reading from stdin.
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if (pair->src_name == stdin_filename) {
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pair->src_fd = STDIN_FILENO;
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setmode(STDIN_FILENO, O_BINARY);
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// We accept only regular files if we are writing the output
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// to disk too, and if --force was not given.
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const bool reg_files_only = !opt_stdout && !opt_force;
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int flags = O_RDONLY | O_BINARY | O_NOCTTY;
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// If we accept only regular files, we need to be careful to avoid
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// problems with special files like devices and FIFOs. O_NONBLOCK
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// prevents blocking when opening such files. When we want to accept
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// special files, we must not use O_NONBLOCK, or otherwise we won't
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// block waiting e.g. FIFOs to become readable.
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#if defined(O_NOFOLLOW)
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#elif !defined(DOSLIKE)
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// Some POSIX-like systems lack O_NOFOLLOW (it's not required
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// by POSIX). Check for symlinks with a separate lstat() on
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if (reg_files_only) {
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if (lstat(pair->src_name, &st)) {
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message_error("%s: %s", pair->src_name,
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} else if (S_ISLNK(st.st_mode)) {
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message_warning(_("%s: Is a symbolic link, "
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"skipping"), pair->src_name);
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// Try to open the file. If we are accepting non-regular files,
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// unblock the caught signals so that open() can be interrupted
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// if it blocks e.g. due to a FIFO file.
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// Maybe this wouldn't need a loop, since all the signal handlers for
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// which we don't use SA_RESTART set user_abort to true. But it
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// doesn't hurt to have it just in case.
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pair->src_fd = open(pair->src_name, flags);
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} while (pair->src_fd == -1 && errno == EINTR && !user_abort);
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if (pair->src_fd == -1) {
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// If we were interrupted, don't display any error message.
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if (errno == EINTR) {
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// All the signals that don't have SA_RESTART
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// Give an understandable error message in if reason
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// for failing was that the file was a symbolic link.
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// Note that at least Linux, OpenBSD, Solaris, and Darwin
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// use ELOOP to indicate if O_NOFOLLOW was the reason
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// that open() failed. Because there may be
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// directories in the pathname, ELOOP may occur also
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// because of a symlink loop in the directory part.
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// So ELOOP doesn't tell us what actually went wrong.
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// FreeBSD associates EMLINK with O_NOFOLLOW and
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// Tru64 uses ENOTSUP. We use these directly here
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// and skip the lstat() call and the associated race.
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// I want to hear if there are other kernels that
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// fail with something else than ELOOP with O_NOFOLLOW.
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bool was_symlink = false;
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# if defined(__FreeBSD__) || defined(__DragonFly__)
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# elif defined(__digital__) && defined(__unix__)
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if (errno == ENOTSUP)
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# elif defined(__NetBSD__)
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// FIXME? As of 2008-11-20, NetBSD doesn't document what
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// errno is used with O_NOFOLLOW. It seems to be EFTYPE,
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// but since it isn't documented, it may be wrong to rely
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if (errno == ELOOP && reg_files_only) {
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const int saved_errno = errno;
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if (lstat(pair->src_name, &st) == 0
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&& S_ISLNK(st.st_mode))
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message_warning(_("%s: Is a symbolic link, "
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"skipping"), pair->src_name);
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// Something else than O_NOFOLLOW failing
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// (assuming that the race conditions didn't
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message_error("%s: %s", pair->src_name,
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// Drop O_NONBLOCK, which is used only when we are accepting only
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// regular files. After the open() call, we want things to block
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// instead of giving EAGAIN.
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if (reg_files_only) {
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flags = fcntl(pair->src_fd, F_GETFL);
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flags &= ~O_NONBLOCK;
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if (fcntl(pair->src_fd, F_SETFL, flags))
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// Stat the source file. We need the result also when we copy
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// the permissions, and when unlinking.
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if (fstat(pair->src_fd, &pair->src_st))
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if (S_ISDIR(pair->src_st.st_mode)) {
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message_warning(_("%s: Is a directory, skipping"),
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if (reg_files_only) {
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if (!S_ISREG(pair->src_st.st_mode)) {
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message_warning(_("%s: Not a regular file, "
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"skipping"), pair->src_name);
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// These are meaningless on Windows.
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if (pair->src_st.st_mode & (S_ISUID | S_ISGID)) {
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// gzip rejects setuid and setgid files even
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// when --force was used. bzip2 doesn't check
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// for them, but calls fchown() after fchmod(),
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// and many systems automatically drop setuid
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// and setgid bits there.
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// We accept setuid and setgid files if
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// --force was used. We drop these bits
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// explicitly in io_copy_attr().
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message_warning(_("%s: File has setuid or "
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"setgid bit set, skipping"),
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if (pair->src_st.st_mode & S_ISVTX) {
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message_warning(_("%s: File has sticky bit "
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if (pair->src_st.st_nlink > 1) {
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message_warning(_("%s: Input file has more "
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"than one hard link, "
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"skipping"), pair->src_name);
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message_error("%s: %s", pair->src_name, strerror(errno));
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(void)close(pair->src_fd);
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/// \brief Closes source file of the file_pair structure
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/// \param pair File whose src_fd should be closed
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/// \param success If true, the file will be removed from the disk if
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/// closing succeeds and --keep hasn't been used.
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io_close_src(file_pair *pair, bool success)
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if (pair->src_fd != STDIN_FILENO && pair->src_fd != -1) {
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(void)close(pair->src_fd);
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// If we are going to unlink(), do it before closing the file.
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// This way there's no risk that someone replaces the file and
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// happens to get same inode number, which would make us
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// unlink() wrong file.
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// NOTE: DOS-like systems are an exception to this, because
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// they don't allow unlinking files that are open. *sigh*
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if (success && !opt_keep_original)
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io_unlink(pair->src_name, &pair->src_st);
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(void)close(pair->src_fd);
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io_open_dest(file_pair *pair)
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if (opt_stdout || pair->src_fd == STDIN_FILENO) {
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// We don't modify or free() this.
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pair->dest_name = (char *)"(stdout)";
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pair->dest_fd = STDOUT_FILENO;
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setmode(STDOUT_FILENO, O_BINARY);
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pair->dest_name = suffix_get_dest_name(pair->src_name);
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if (pair->dest_name == NULL)
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// If --force was used, unlink the target file first.
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if (opt_force && unlink(pair->dest_name) && errno != ENOENT) {
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message_error("%s: Cannot unlink: %s",
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pair->dest_name, strerror(errno));
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free(pair->dest_name);
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if (opt_force && unlink(pair->dest_name) && errno != ENOENT) {
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message_error("%s: Cannot unlink: %s", pair->dest_name,
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free(pair->dest_name);
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const int flags = O_WRONLY | O_BINARY | O_NOCTTY | O_CREAT | O_EXCL;
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const mode_t mode = S_IRUSR | S_IWUSR;
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pair->dest_fd = open(pair->dest_name, flags, mode);
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if (pair->dest_fd == -1) {
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// Don't bother with error message if user requested
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// us to exit anyway.
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message_error("%s: %s", pair->dest_name,
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free(pair->dest_name);
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// If this really fails... well, we have a safe fallback.
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if (fstat(pair->dest_fd, &pair->dest_st)) {
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pair->dest_st.st_dev = 0;
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pair->dest_st.st_ino = 0;
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/// \brief Closes destination file of the file_pair structure
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/// \param pair File whose dest_fd should be closed
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/// \param success If false, the file will be removed from the disk.
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/// \return Zero if closing succeeds. On error, -1 is returned and
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/// error message printed.
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io_close_dest(file_pair *pair, bool success)
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if (pair->dest_fd == -1 || pair->dest_fd == STDOUT_FILENO)
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if (close(pair->dest_fd)) {
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message_error(_("%s: Closing the file failed: %s"),
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pair->dest_name, strerror(errno));
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// Closing destination file failed, so we cannot trust its
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// contents. Get rid of junk:
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io_unlink(pair->dest_name, &pair->dest_st);
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free(pair->dest_name);
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// If the operation using this file wasn't successful, we git rid
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io_unlink(pair->dest_name, &pair->dest_st);
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free(pair->dest_name);
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io_open(const char *src_name)
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if (is_empty_filename(src_name))
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// Since we have only one file open at a time, we can use
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// a statically allocated structure.
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static file_pair pair;
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.src_name = src_name,
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// Block the signals, for which we have a custom signal handler, so
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// that we don't need to worry about EINTR.
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file_pair *ret = NULL;
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if (!io_open_src(&pair)) {
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// io_open_src() may have unblocked the signals temporarily,
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// and thus user_abort may have got set even if open()
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if (user_abort || io_open_dest(&pair))
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io_close_src(&pair, false);
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io_close(file_pair *pair, bool success)
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if (success && pair->dest_fd != STDOUT_FILENO)
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// Close the destination first. If it fails, we must not remove
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if (io_close_dest(pair, success))
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// Close the source file, and unlink it if the operation using this
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// file pair was successful and we haven't requested to keep the
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io_close_src(pair, success);
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io_read(file_pair *pair, uint8_t *buf, size_t size)
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// We use small buffers here.
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assert(size < SSIZE_MAX);
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const ssize_t amount = read(pair->src_fd, buf, left);
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pair->src_eof = true;
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if (errno == EINTR) {
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message_error(_("%s: Read error: %s"),
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pair->src_name, strerror(errno));
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// FIXME Is this needed?
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pair->src_eof = true;
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buf += (size_t)(amount);
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left -= (size_t)(amount);
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io_write(const file_pair *pair, const uint8_t *buf, size_t size)
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assert(size < SSIZE_MAX);
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const ssize_t amount = write(pair->dest_fd, buf, size);
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if (errno == EINTR) {
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// Handle broken pipe specially. gzip and bzip2
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// don't print anything on SIGPIPE. In addition,
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// gzip --quiet uses exit status 2 (warning) on
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// broken pipe instead of whatever raise(SIGPIPE)
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// would make it return. It is there to hide "Broken
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// pipe" message on some old shells (probably old
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// We don't do anything special with --quiet, which
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// is what bzip2 does too. If we get SIGPIPE, we
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// will handle it like other signals by setting
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// user_abort, and get EPIPE here.
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message_error(_("%s: Write error: %s"),
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pair->dest_name, strerror(errno));
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buf += (size_t)(amount);
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size -= (size_t)(amount);
added
removed
storage/tokudb/ft-index/third_party/xz-4.999.9beta/src/xz/file_io.c
