--- /dev/null
+/* System-dependent calls for tar.
+
+ Copyright (C) 2003 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 2, 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, write to the Free Software Foundation, Inc.,
+ 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#include "system.h"
+
+#include "common.h"
+#include "rmt.h"
+
+#if MSDOS
+
+bool
+sys_get_archive_stat ()
+{
+ return 0;
+}
+
+bool
+sys_file_is_archive (struct tar_stat_info *p)
+{
+ return false;
+}
+
+void
+sys_save_archive_dev_ino ()
+{
+}
+
+void
+sys_detect_dev_null_output ()
+{
+ static char const dev_null[] = "nul";
+
+ dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0
+ || (! _isrmt (archive)));
+}
+
+void
+sys_drain_input_pipe ()
+{
+}
+
+void
+sys_wait_for_child (pid_t child_pid)
+{
+}
+
+void
+sys_spawn_shell ()
+{
+ spawnl (P_WAIT, getenv ("COMSPEC"), "-", 0);
+}
+
+void
+sys_compare_uid_gid (struct stat *a, struct stat *b)
+{
+ /* stat() in djgpp's C library gives a constant number of 42 as the
+ uid and gid of a file. So, comparing an FTP'ed archive just after
+ unpack would fail on MSDOS. */
+}
+
+void
+sys_compare_links (struct stat *link_data, struct stat *stat_data)
+{
+}
+
+int
+sys_truncate (int fd)
+{
+ return write (fd, "", 0);
+}
+
+void
+sys_reset_uid_gid ()
+{
+}
+
+ssize_t
+sys_write_archive_buffer (void)
+{
+ ssize_t status;
+ ssize_t written = 0;
+
+ while (0 <= (status = full_write (archive, record_start->buffer + written,
+ record_size - written)))
+ {
+ written += status;
+ if (written == record_size)
+ break;
+ }
+
+ return written ? written : status;
+}
+
+/* Set ARCHIVE for writing, then compressing an archive. */
+void
+sys_child_open_for_compress (void)
+{
+ FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives")));
+}
+
+/* Set ARCHIVE for uncompressing, then reading an archive. */
+void
+sys_child_open_for_uncompress (void)
+{
+ FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives")));
+}
+
+#else
+
+extern union block *record_start; /* FIXME */
+
+static struct stat archive_stat; /* stat block for archive file */
+
+bool
+sys_get_archive_stat ()
+{
+ return fstat (archive, &archive_stat) == 0;
+}
+
+bool
+sys_file_is_archive (struct tar_stat_info *p)
+{
+ return (ar_dev && p->stat.st_dev == ar_dev && p->stat.st_ino == ar_ino);
+}
+
+/* Save archive file inode and device numbers */
+void
+sys_save_archive_dev_ino ()
+{
+ if (!_isrmt (archive) && S_ISREG (archive_stat.st_mode))
+ {
+ ar_dev = archive_stat.st_dev;
+ ar_ino = archive_stat.st_ino;
+ }
+ else
+ ar_dev = 0;
+}
+
+/* Detect if outputting to "/dev/null". */
+void
+sys_detect_dev_null_output ()
+{
+ static char const dev_null[] = "/dev/null";
+ struct stat dev_null_stat;
+
+ dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0
+ || (! _isrmt (archive)
+ && S_ISCHR (archive_stat.st_mode)
+ && stat (dev_null, &dev_null_stat) == 0
+ && archive_stat.st_dev == dev_null_stat.st_dev
+ && archive_stat.st_ino == dev_null_stat.st_ino));
+}
+
+/* Manage to fully drain a pipe we might be reading, so to not break it on
+ the producer after the EOF block. FIXME: one of these days, GNU tar
+ might become clever enough to just stop working, once there is no more
+ work to do, we might have to revise this area in such time. */
+
+void
+sys_drain_input_pipe ()
+{
+ if (access_mode == ACCESS_READ
+ && ! _isrmt (archive)
+ && (S_ISFIFO (archive_stat.st_mode) || S_ISSOCK (archive_stat.st_mode)))
+ while (rmtread (archive, record_start->buffer, record_size) > 0)
+ continue;
+}
+
+void
+sys_wait_for_child (pid_t child_pid)
+{
+ if (child_pid)
+ {
+ int wait_status;
+
+ while (waitpid (child_pid, &wait_status, 0) == -1)
+ if (errno != EINTR)
+ {
+ waitpid_error (use_compress_program_option);
+ break;
+ }
+
+ if (WIFSIGNALED (wait_status))
+ ERROR ((0, 0, _("Child died with signal %d"),
+ WTERMSIG (wait_status)));
+ else if (WEXITSTATUS (wait_status) != 0)
+ ERROR ((0, 0, _("Child returned status %d"),
+ WEXITSTATUS (wait_status)));
+ }
+}
+
+void
+sys_spawn_shell ()
+{
+ pid_t child;
+ const char *shell = getenv ("SHELL");
+ if (! shell)
+ shell = "/bin/sh";
+ child = xfork ();
+ if (child == 0)
+ {
+ execlp (shell, "-sh", "-i", 0);
+ exec_fatal (shell);
+ }
+ else
+ {
+ int wait_status;
+ while (waitpid (child, &wait_status, 0) == -1)
+ if (errno != EINTR)
+ {
+ waitpid_error (shell);
+ break;
+ }
+ }
+}
+
+void
+sys_compare_uid_gid (struct stat *a, struct stat *b)
+{
+ if (a->st_uid != b->st_uid)
+ report_difference (_("Uid differs"));
+ if (a->st_gid != b->st_gid)
+ report_difference (_("Gid differs"));
+}
+
+void
+sys_compare_links (struct stat *link_data, struct stat *stat_data)
+{
+ if (stat_data->st_dev != link_data->st_dev
+ || stat_data->st_ino != link_data->st_ino)
+ {
+ report_difference (_("Not linked to %s"),
+ quote (current_stat_info.link_name));
+ }
+}
+
+int
+sys_truncate (int fd)
+{
+ off_t pos = lseek (fd, (off_t) 0, SEEK_CUR);
+ return pos < 0 ? -1 : ftruncate (fd, pos);
+}
+
+void
+sys_reset_uid_gid ()
+{
+ setuid (getuid ());
+ setgid (getgid ());
+}
+
+/* Return nonzero if NAME is the name of a regular file, or if the file
+ does not exist (so it would be created as a regular file). */
+static int
+is_regular_file (const char *name)
+{
+ struct stat stbuf;
+
+ if (stat (name, &stbuf) == 0)
+ return S_ISREG (stbuf.st_mode);
+ else
+ return errno == ENOENT;
+}
+
+ssize_t
+sys_write_archive_buffer (void)
+{
+ ssize_t status;
+ ssize_t written = 0;
+
+ while (0 <= (status = rmtwrite (archive, record_start->buffer + written,
+ record_size - written)))
+ {
+ written += status;
+ if (written == record_size
+ || _isrmt (archive)
+ || ! (S_ISFIFO (archive_stat.st_mode)
+ || S_ISSOCK (archive_stat.st_mode)))
+ break;
+ }
+
+ return written ? written : status;
+}
+
+#define PREAD 0 /* read file descriptor from pipe() */
+#define PWRITE 1 /* write file descriptor from pipe() */
+
+/* Duplicate file descriptor FROM into becoming INTO.
+ INTO is closed first and has to be the next available slot. */
+static void
+xdup2 (int from, int into)
+{
+ if (from != into)
+ {
+ int status = close (into);
+
+ if (status != 0 && errno != EBADF)
+ {
+ int e = errno;
+ FATAL_ERROR ((0, e, _("Cannot close")));
+ }
+ status = dup (from);
+ if (status != into)
+ {
+ if (status < 0)
+ {
+ int e = errno;
+ FATAL_ERROR ((0, e, _("Cannot dup")));
+ }
+ abort ();
+ }
+ xclose (from);
+ }
+}
+
+/* Set ARCHIVE for writing, then compressing an archive. */
+pid_t
+sys_child_open_for_compress (void)
+{
+ int parent_pipe[2];
+ int child_pipe[2];
+ pid_t grandchild_pid;
+ pid_t child_pid;
+ int wait_status;
+
+ xpipe (parent_pipe);
+ child_pid = xfork ();
+
+ if (child_pid > 0)
+ {
+ /* The parent tar is still here! Just clean up. */
+
+ archive = parent_pipe[PWRITE];
+ xclose (parent_pipe[PREAD]);
+ return child_pid;
+ }
+
+ /* The new born child tar is here! */
+
+ program_name = _("tar (child)");
+
+ xdup2 (parent_pipe[PREAD], STDIN_FILENO);
+ xclose (parent_pipe[PWRITE]);
+
+ /* Check if we need a grandchild tar. This happens only if either:
+ a) we are writing stdout: to force reblocking;
+ b) the file is to be accessed by rmt: compressor doesn't know how;
+ c) the file is not a plain file. */
+
+ if (strcmp (archive_name_array[0], "-") != 0
+ && !_remdev (archive_name_array[0])
+ && is_regular_file (archive_name_array[0]))
+ {
+ if (backup_option)
+ maybe_backup_file (archive_name_array[0], 1);
+
+ /* We don't need a grandchild tar. Open the archive and launch the
+ compressor. */
+
+ archive = creat (archive_name_array[0], MODE_RW);
+ if (archive < 0)
+ {
+ int saved_errno = errno;
+
+ if (backup_option)
+ undo_last_backup ();
+ errno = saved_errno;
+ open_fatal (archive_name_array[0]);
+ }
+ xdup2 (archive, STDOUT_FILENO);
+ execlp (use_compress_program_option, use_compress_program_option,
+ (char *) 0);
+ exec_fatal (use_compress_program_option);
+ }
+
+ /* We do need a grandchild tar. */
+
+ xpipe (child_pipe);
+ grandchild_pid = xfork ();
+
+ if (grandchild_pid == 0)
+ {
+ /* The newborn grandchild tar is here! Launch the compressor. */
+
+ program_name = _("tar (grandchild)");
+
+ xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
+ xclose (child_pipe[PREAD]);
+ execlp (use_compress_program_option, use_compress_program_option,
+ (char *) 0);
+ exec_fatal (use_compress_program_option);
+ }
+
+ /* The child tar is still here! */
+
+ /* Prepare for reblocking the data from the compressor into the archive. */
+
+ xdup2 (child_pipe[PREAD], STDIN_FILENO);
+ xclose (child_pipe[PWRITE]);
+
+ if (strcmp (archive_name_array[0], "-") == 0)
+ archive = STDOUT_FILENO;
+ else
+ {
+ archive = rmtcreat (archive_name_array[0], MODE_RW, rsh_command_option);
+ if (archive < 0)
+ open_fatal (archive_name_array[0]);
+ }
+
+ /* Let's read out of the stdin pipe and write an archive. */
+
+ while (1)
+ {
+ ssize_t status = 0;
+ char *cursor;
+ size_t length;
+
+ /* Assemble a record. */
+
+ for (length = 0, cursor = record_start->buffer;
+ length < record_size;
+ length += status, cursor += status)
+ {
+ size_t size = record_size - length;
+
+ status = safe_read (STDIN_FILENO, cursor, size);
+ if (status <= 0)
+ break;
+ }
+
+ if (status < 0)
+ read_fatal (use_compress_program_option);
+
+ /* Copy the record. */
+
+ if (status == 0)
+ {
+ /* We hit the end of the file. Write last record at
+ full length, as the only role of the grandchild is
+ doing proper reblocking. */
+
+ if (length > 0)
+ {
+ memset (record_start->buffer + length, 0, record_size - length);
+ status = sys_write_archive_buffer ();
+ if (status != record_size)
+ archive_write_error (status);
+ }
+
+ /* There is nothing else to read, break out. */
+ break;
+ }
+
+ status = sys_write_archive_buffer ();
+ if (status != record_size)
+ archive_write_error (status);
+ }
+
+ /* Propagate any failure of the grandchild back to the parent. */
+
+ while (waitpid (grandchild_pid, &wait_status, 0) == -1)
+ if (errno != EINTR)
+ {
+ waitpid_error (use_compress_program_option);
+ break;
+ }
+
+ if (WIFSIGNALED (wait_status))
+ {
+ kill (child_pid, WTERMSIG (wait_status));
+ exit_status = TAREXIT_FAILURE;
+ }
+ else if (WEXITSTATUS (wait_status) != 0)
+ exit_status = WEXITSTATUS (wait_status);
+
+ exit (exit_status);
+}
+
+/* Set ARCHIVE for uncompressing, then reading an archive. */
+pid_t
+sys_child_open_for_uncompress (void)
+{
+ int parent_pipe[2];
+ int child_pipe[2];
+ pid_t grandchild_pid;
+ pid_t child_pid;
+ int wait_status;
+
+ xpipe (parent_pipe);
+ child_pid = xfork ();
+
+ if (child_pid > 0)
+ {
+ /* The parent tar is still here! Just clean up. */
+
+ read_full_records_option = 1;
+ archive = parent_pipe[PREAD];
+ xclose (parent_pipe[PWRITE]);
+ return child_pid;
+ }
+
+ /* The newborn child tar is here! */
+
+ program_name = _("tar (child)");
+
+ xdup2 (parent_pipe[PWRITE], STDOUT_FILENO);
+ xclose (parent_pipe[PREAD]);
+
+ /* Check if we need a grandchild tar. This happens only if either:
+ a) we're reading stdin: to force unblocking;
+ b) the file is to be accessed by rmt: compressor doesn't know how;
+ c) the file is not a plain file. */
+
+ if (strcmp (archive_name_array[0], "-") != 0
+ && !_remdev (archive_name_array[0])
+ && is_regular_file (archive_name_array[0]))
+ {
+ /* We don't need a grandchild tar. Open the archive and lauch the
+ uncompressor. */
+
+ archive = open (archive_name_array[0], O_RDONLY | O_BINARY, MODE_RW);
+ if (archive < 0)
+ open_fatal (archive_name_array[0]);
+ xdup2 (archive, STDIN_FILENO);
+ execlp (use_compress_program_option, use_compress_program_option,
+ "-d", (char *) 0);
+ exec_fatal (use_compress_program_option);
+ }
+
+ /* We do need a grandchild tar. */
+
+ xpipe (child_pipe);
+ grandchild_pid = xfork ();
+
+ if (grandchild_pid == 0)
+ {
+ /* The newborn grandchild tar is here! Launch the uncompressor. */
+
+ program_name = _("tar (grandchild)");
+
+ xdup2 (child_pipe[PREAD], STDIN_FILENO);
+ xclose (child_pipe[PWRITE]);
+ execlp (use_compress_program_option, use_compress_program_option,
+ "-d", (char *) 0);
+ exec_fatal (use_compress_program_option);
+ }
+
+ /* The child tar is still here! */
+
+ /* Prepare for unblocking the data from the archive into the
+ uncompressor. */
+
+ xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
+ xclose (child_pipe[PREAD]);
+
+ if (strcmp (archive_name_array[0], "-") == 0)
+ archive = STDIN_FILENO;
+ else
+ archive = rmtopen (archive_name_array[0], O_RDONLY | O_BINARY,
+ MODE_RW, rsh_command_option);
+ if (archive < 0)
+ open_fatal (archive_name_array[0]);
+
+ /* Let's read the archive and pipe it into stdout. */
+
+ while (1)
+ {
+ char *cursor;
+ size_t maximum;
+ size_t count;
+ ssize_t status;
+
+ clear_read_error_count ();
+
+ error_loop:
+ status = rmtread (archive, record_start->buffer, record_size);
+ if (status < 0)
+ {
+ archive_read_error ();
+ goto error_loop;
+ }
+ if (status == 0)
+ break;
+ cursor = record_start->buffer;
+ maximum = status;
+ while (maximum)
+ {
+ count = maximum < BLOCKSIZE ? maximum : BLOCKSIZE;
+ if (full_write (STDOUT_FILENO, cursor, count) != count)
+ write_error (use_compress_program_option);
+ cursor += count;
+ maximum -= count;
+ }
+ }
+
+ xclose (STDOUT_FILENO);
+
+ /* Propagate any failure of the grandchild back to the parent. */
+
+ while (waitpid (grandchild_pid, &wait_status, 0) == -1)
+ if (errno != EINTR)
+ {
+ waitpid_error (use_compress_program_option);
+ break;
+ }
+
+ if (WIFSIGNALED (wait_status))
+ {
+ kill (child_pid, WTERMSIG (wait_status));
+ exit_status = TAREXIT_FAILURE;
+ }
+ else if (WEXITSTATUS (wait_status) != 0)
+ exit_status = WEXITSTATUS (wait_status);
+
+ exit (exit_status);
+}
+
+#endif /* not MSDOS */
+
projects / chaz / tar / commitdiff
