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-rw-r--r--contrib/tar/src/misc.c847
1 files changed, 847 insertions, 0 deletions
diff --git a/contrib/tar/src/misc.c b/contrib/tar/src/misc.c
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+/* Miscellaneous functions, not really specific to GNU tar.
+
+ Copyright 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001 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 "rmt.h"
+#include "common.h"
+#include <quotearg.h>
+#include <save-cwd.h>
+
+static void call_arg_fatal PARAMS ((char const *, char const *))
+ __attribute__ ((noreturn));
+
+/* Handling strings. */
+
+/* Assign STRING to a copy of VALUE if not zero, or to zero. If
+ STRING was nonzero, it is freed first. */
+void
+assign_string (char **string, const char *value)
+{
+ if (*string)
+ free (*string);
+ *string = value ? xstrdup (value) : 0;
+}
+
+/* Allocate a copy of the string quoted as in C, and returns that. If
+ the string does not have to be quoted, it returns a null pointer.
+ The allocated copy should normally be freed with free() after the
+ caller is done with it.
+
+ This is used in one context only: generating the directory file in
+ incremental dumps. The quoted string is not intended for human
+ consumption; it is intended only for unquote_string. The quoting
+ is locale-independent, so that users needn't worry about locale
+ when reading directory files. This means that we can't use
+ quotearg, as quotearg is locale-dependent and is meant for human
+ consumption. */
+char *
+quote_copy_string (const char *string)
+{
+ const char *source = string;
+ char *destination = 0;
+ char *buffer = 0;
+ int copying = 0;
+
+ while (*source)
+ {
+ int character = *source++;
+
+ switch (character)
+ {
+ case '\n': case '\\':
+ if (!copying)
+ {
+ size_t length = (source - string) - 1;
+
+ copying = 1;
+ buffer = xmalloc (length + 2 + 2 * strlen (source) + 1);
+ memcpy (buffer, string, length);
+ destination = buffer + length;
+ }
+ *destination++ = '\\';
+ *destination++ = character == '\\' ? '\\' : 'n';
+ break;
+
+ default:
+ if (copying)
+ *destination++ = character;
+ break;
+ }
+ }
+ if (copying)
+ {
+ *destination = '\0';
+ return buffer;
+ }
+ return 0;
+}
+
+/* Takes a quoted C string (like those produced by quote_copy_string)
+ and turns it back into the un-quoted original. This is done in
+ place. Returns 0 only if the string was not properly quoted, but
+ completes the unquoting anyway.
+
+ This is used for reading the saved directory file in incremental
+ dumps. It is used for decoding old `N' records (demangling names).
+ But also, it is used for decoding file arguments, would they come
+ from the shell or a -T file, and for decoding the --exclude
+ argument. */
+int
+unquote_string (char *string)
+{
+ int result = 1;
+ char *source = string;
+ char *destination = string;
+
+ /* Escape sequences other than \\ and \n are no longer generated by
+ quote_copy_string, but accept them for backwards compatibility,
+ and also because unquote_string is used for purposes other than
+ parsing the output of quote_copy_string. */
+
+ while (*source)
+ if (*source == '\\')
+ switch (*++source)
+ {
+ case '\\':
+ *destination++ = '\\';
+ source++;
+ break;
+
+ case 'n':
+ *destination++ = '\n';
+ source++;
+ break;
+
+ case 't':
+ *destination++ = '\t';
+ source++;
+ break;
+
+ case 'f':
+ *destination++ = '\f';
+ source++;
+ break;
+
+ case 'b':
+ *destination++ = '\b';
+ source++;
+ break;
+
+ case 'r':
+ *destination++ = '\r';
+ source++;
+ break;
+
+ case '?':
+ *destination++ = 0177;
+ source++;
+ break;
+
+ case '0':
+ case '1':
+ case '2':
+ case '3':
+ case '4':
+ case '5':
+ case '6':
+ case '7':
+ {
+ int value = *source++ - '0';
+
+ if (*source < '0' || *source > '7')
+ {
+ *destination++ = value;
+ break;
+ }
+ value = value * 8 + *source++ - '0';
+ if (*source < '0' || *source > '7')
+ {
+ *destination++ = value;
+ break;
+ }
+ value = value * 8 + *source++ - '0';
+ *destination++ = value;
+ break;
+ }
+
+ default:
+ result = 0;
+ *destination++ = '\\';
+ if (*source)
+ *destination++ = *source++;
+ break;
+ }
+ else if (source != destination)
+ *destination++ = *source++;
+ else
+ source++, destination++;
+
+ if (source != destination)
+ *destination = '\0';
+ return result;
+}
+
+/* Return nonzero if NAME contains ".." as a path name component. */
+int
+contains_dot_dot (char const *name)
+{
+ char const *p = name + FILESYSTEM_PREFIX_LEN (name);
+
+ for (;;)
+ {
+ if (p[0] == '.' && p[1] == '.' && (ISSLASH (p[2]) || !p[2]))
+ return 1;
+
+ do
+ {
+ if (! *p++)
+ return 0;
+ }
+ while (! ISSLASH (*p));
+ }
+}
+
+/* File handling. */
+
+/* Saved names in case backup needs to be undone. */
+static char *before_backup_name;
+static char *after_backup_name;
+
+/* Some implementations of rmdir let you remove the working directory.
+ Report an error with errno set to zero for obvious cases of this;
+ otherwise call rmdir. */
+static int
+safer_rmdir (const char *path)
+{
+ while (path[0] == '.' && ISSLASH (path[1]))
+ {
+ path++;
+
+ do path++;
+ while (ISSLASH (*path));
+ }
+
+ if (! path[0] || (path[0] == '.' && ! path[1]))
+ {
+ errno = 0;
+ return -1;
+ }
+
+ return rmdir (path);
+}
+
+/* Remove PATH. If PATH is a directory, then if RECURSE is set remove
+ it recursively; otherwise, remove it only if it is empty. Return 0
+ on error, with errno set; if PATH is obviously the working
+ directory return zero with errno set to zero. */
+int
+remove_any_file (const char *path, int recurse)
+{
+ /* Try unlink first if we are not root, as this saves us a system
+ call in the common case where we're removing a non-directory. */
+ if (! we_are_root)
+ {
+ if (unlink (path) == 0)
+ return 1;
+ if (errno != EPERM)
+ return 0;
+ }
+
+ if (safer_rmdir (path) == 0)
+ return 1;
+
+ switch (errno)
+ {
+ case ENOTDIR:
+ return we_are_root && unlink (path) == 0;
+
+ case 0:
+ case EEXIST:
+#if defined ENOTEMPTY && ENOTEMPTY != EEXIST
+ case ENOTEMPTY:
+#endif
+ if (recurse)
+ {
+ char *directory = savedir (path);
+ char const *entry;
+ size_t entrylen;
+
+ if (! directory)
+ return 0;
+
+ for (entry = directory;
+ (entrylen = strlen (entry)) != 0;
+ entry += entrylen + 1)
+ {
+ char *path_buffer = new_name (path, entry);
+ int r = remove_any_file (path_buffer, 1);
+ int e = errno;
+ free (path_buffer);
+
+ if (! r)
+ {
+ free (directory);
+ errno = e;
+ return 0;
+ }
+ }
+
+ free (directory);
+ return safer_rmdir (path) == 0;
+ }
+ break;
+ }
+
+ return 0;
+}
+
+/* Check if PATH already exists and make a backup of it right now.
+ Return success (nonzero) only if the backup in either unneeded, or
+ successful. For now, directories are considered to never need
+ backup. If ARCHIVE is nonzero, this is the archive and so, we do
+ not have to backup block or character devices, nor remote entities. */
+int
+maybe_backup_file (const char *path, int archive)
+{
+ struct stat file_stat;
+
+ /* Check if we really need to backup the file. */
+
+ if (archive && _remdev (path))
+ return 1;
+
+ if (stat (path, &file_stat))
+ {
+ if (errno == ENOENT)
+ return 1;
+
+ stat_error (path);
+ return 0;
+ }
+
+ if (S_ISDIR (file_stat.st_mode))
+ return 1;
+
+ if (archive && (S_ISBLK (file_stat.st_mode) || S_ISCHR (file_stat.st_mode)))
+ return 1;
+
+ assign_string (&before_backup_name, path);
+
+ /* A run situation may exist between Emacs or other GNU programs trying to
+ make a backup for the same file simultaneously. If theoretically
+ possible, real problems are unlikely. Doing any better would require a
+ convention, GNU-wide, for all programs doing backups. */
+
+ assign_string (&after_backup_name, 0);
+ after_backup_name = find_backup_file_name (path, backup_type);
+ if (! after_backup_name)
+ xalloc_die ();
+
+ if (rename (before_backup_name, after_backup_name) == 0)
+ {
+ if (verbose_option)
+ fprintf (stdlis, _("Renaming %s to %s\n"),
+ quote_n (0, before_backup_name),
+ quote_n (1, after_backup_name));
+ return 1;
+ }
+ else
+ {
+ /* The backup operation failed. */
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot rename to %s"),
+ quotearg_colon (before_backup_name),
+ quote_n (1, after_backup_name)));
+ assign_string (&after_backup_name, 0);
+ return 0;
+ }
+}
+
+/* Try to restore the recently backed up file to its original name.
+ This is usually only needed after a failed extraction. */
+void
+undo_last_backup (void)
+{
+ if (after_backup_name)
+ {
+ if (rename (after_backup_name, before_backup_name) != 0)
+ {
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot rename to %s"),
+ quotearg_colon (after_backup_name),
+ quote_n (1, before_backup_name)));
+ }
+ if (verbose_option)
+ fprintf (stdlis, _("Renaming %s back to %s\n"),
+ quote_n (0, after_backup_name),
+ quote_n (1, before_backup_name));
+ assign_string (&after_backup_name, 0);
+ }
+}
+
+/* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
+int
+deref_stat (int deref, char const *name, struct stat *buf)
+{
+ return deref ? stat (name, buf) : lstat (name, buf);
+}
+
+/* A description of a working directory. */
+struct wd
+{
+ char const *name;
+ int saved;
+ struct saved_cwd saved_cwd;
+};
+
+/* A vector of chdir targets. wd[0] is the initial working directory. */
+static struct wd *wd;
+
+/* The number of working directories in the vector. */
+static size_t wds;
+
+/* The allocated size of the vector. */
+static size_t wd_alloc;
+
+/* DIR is the operand of a -C option; add it to vector of chdir targets,
+ and return the index of its location. */
+int
+chdir_arg (char const *dir)
+{
+ if (wds == wd_alloc)
+ {
+ wd_alloc = 2 * (wd_alloc + 1);
+ wd = xrealloc (wd, sizeof *wd * wd_alloc);
+ if (! wds)
+ {
+ wd[wds].name = ".";
+ wd[wds].saved = 0;
+ wds++;
+ }
+ }
+
+ /* Optimize the common special case of the working directory,
+ or the working directory as a prefix. */
+ if (dir[0])
+ {
+ while (dir[0] == '.' && ISSLASH (dir[1]))
+ for (dir += 2; ISSLASH (*dir); dir++)
+ continue;
+ if (! dir[dir[0] == '.'])
+ return wds - 1;
+ }
+
+ wd[wds].name = dir;
+ wd[wds].saved = 0;
+ return wds++;
+}
+
+/* Change to directory I. If I is 0, change to the initial working
+ directory; otherwise, I must be a value returned by chdir_arg. */
+void
+chdir_do (int i)
+{
+ static int previous;
+
+ if (previous != i)
+ {
+ struct wd *prev = &wd[previous];
+ struct wd *curr = &wd[i];
+
+ if (! prev->saved)
+ {
+ prev->saved = 1;
+ if (save_cwd (&prev->saved_cwd) != 0)
+ FATAL_ERROR ((0, 0, _("Cannot save working directory")));
+ }
+
+ if (curr->saved)
+ {
+ if (restore_cwd (&curr->saved_cwd, curr->name, prev->name))
+ FATAL_ERROR ((0, 0, _("Cannot change working directory")));
+ }
+ else
+ {
+ if (i && ! ISSLASH (curr->name[0]))
+ chdir_do (i - 1);
+ if (chdir (curr->name) != 0)
+ chdir_fatal (curr->name);
+ }
+
+ previous = i;
+ }
+}
+
+/* Decode MODE from its binary form in a stat structure, and encode it
+ into a 9-byte string STRING, terminated with a NUL. */
+
+void
+decode_mode (mode_t mode, char *string)
+{
+ *string++ = mode & S_IRUSR ? 'r' : '-';
+ *string++ = mode & S_IWUSR ? 'w' : '-';
+ *string++ = (mode & S_ISUID
+ ? (mode & S_IXUSR ? 's' : 'S')
+ : (mode & S_IXUSR ? 'x' : '-'));
+ *string++ = mode & S_IRGRP ? 'r' : '-';
+ *string++ = mode & S_IWGRP ? 'w' : '-';
+ *string++ = (mode & S_ISGID
+ ? (mode & S_IXGRP ? 's' : 'S')
+ : (mode & S_IXGRP ? 'x' : '-'));
+ *string++ = mode & S_IROTH ? 'r' : '-';
+ *string++ = mode & S_IWOTH ? 'w' : '-';
+ *string++ = (mode & S_ISVTX
+ ? (mode & S_IXOTH ? 't' : 'T')
+ : (mode & S_IXOTH ? 'x' : '-'));
+ *string = '\0';
+}
+
+/* Report an error associated with the system call CALL and the
+ optional name NAME. */
+static void
+call_arg_error (char const *call, char const *name)
+{
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot %s"), quotearg_colon (name), call));
+}
+
+/* Report a fatal error associated with the system call CALL and
+ the optional file name NAME. */
+static void
+call_arg_fatal (char const *call, char const *name)
+{
+ int e = errno;
+ FATAL_ERROR ((0, e, _("%s: Cannot %s"), quotearg_colon (name), call));
+}
+
+/* Report a warning associated with the system call CALL and
+ the optional file name NAME. */
+static void
+call_arg_warn (char const *call, char const *name)
+{
+ int e = errno;
+ WARN ((0, e, _("%s: Warning: Cannot %s"), quotearg_colon (name), call));
+}
+
+void
+chdir_fatal (char const *name)
+{
+ call_arg_fatal ("chdir", name);
+}
+
+void
+chmod_error_details (char const *name, mode_t mode)
+{
+ int e = errno;
+ char buf[10];
+ decode_mode (mode, buf);
+ ERROR ((0, e, _("%s: Cannot change mode to %s"),
+ quotearg_colon (name), buf));
+}
+
+void
+chown_error_details (char const *name, uid_t uid, gid_t gid)
+{
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot change ownership to uid %lu, gid %lu"),
+ quotearg_colon (name), (unsigned long) uid, (unsigned long) gid));
+}
+
+void
+close_error (char const *name)
+{
+ call_arg_error ("close", name);
+}
+
+void
+close_fatal (char const *name)
+{
+ call_arg_fatal ("close", name);
+}
+
+void
+close_warn (char const *name)
+{
+ call_arg_warn ("close", name);
+}
+
+void
+exec_fatal (char const *name)
+{
+ call_arg_fatal ("exec", name);
+}
+
+void
+link_error (char const *target, char const *source)
+{
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot hard link to %s"),
+ quotearg_colon (source), quote_n (1, target)));
+}
+
+void
+mkdir_error (char const *name)
+{
+ call_arg_error ("mkdir", name);
+}
+
+void
+mkfifo_error (char const *name)
+{
+ call_arg_error ("mkfifo", name);
+}
+
+void
+mknod_error (char const *name)
+{
+ call_arg_error ("mknod", name);
+}
+
+void
+open_error (char const *name)
+{
+ call_arg_error ("open", name);
+}
+
+void
+open_fatal (char const *name)
+{
+ call_arg_fatal ("open", name);
+}
+
+void
+open_warn (char const *name)
+{
+ call_arg_warn ("open", name);
+}
+
+void
+read_error (char const *name)
+{
+ call_arg_error ("read", name);
+}
+
+void
+read_error_details (char const *name, off_t offset, size_t size)
+{
+ char buf[UINTMAX_STRSIZE_BOUND];
+ int e = errno;
+ ERROR ((0, e,
+ _("%s: Read error at byte %s, reading %lu bytes"),
+ quotearg_colon (name), STRINGIFY_BIGINT (offset, buf),
+ (unsigned long) size));
+}
+
+void
+read_warn_details (char const *name, off_t offset, size_t size)
+{
+ char buf[UINTMAX_STRSIZE_BOUND];
+ int e = errno;
+ WARN ((0, e,
+ _("%s: Warning: Read error at byte %s, reading %lu bytes"),
+ quotearg_colon (name), STRINGIFY_BIGINT (offset, buf),
+ (unsigned long) size));
+}
+
+void
+read_fatal (char const *name)
+{
+ call_arg_fatal ("read", name);
+}
+
+void
+read_fatal_details (char const *name, off_t offset, size_t size)
+{
+ char buf[UINTMAX_STRSIZE_BOUND];
+ int e = errno;
+ FATAL_ERROR ((0, e,
+ _("%s: Read error at byte %s, reading %lu bytes"),
+ quotearg_colon (name), STRINGIFY_BIGINT (offset, buf),
+ (unsigned long) size));
+}
+
+void
+readlink_error (char const *name)
+{
+ call_arg_error ("readlink", name);
+}
+
+void
+readlink_warn (char const *name)
+{
+ call_arg_warn ("readlink", name);
+}
+
+void
+savedir_error (char const *name)
+{
+ call_arg_error ("savedir", name);
+}
+
+void
+savedir_warn (char const *name)
+{
+ call_arg_warn ("savedir", name);
+}
+
+void
+seek_error (char const *name)
+{
+ call_arg_error ("seek", name);
+}
+
+void
+seek_error_details (char const *name, off_t offset)
+{
+ char buf[UINTMAX_STRSIZE_BOUND];
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot seek to %s"),
+ quotearg_colon (name),
+ STRINGIFY_BIGINT (offset, buf)));
+}
+
+void
+seek_warn (char const *name)
+{
+ call_arg_warn ("seek", name);
+}
+
+void
+seek_warn_details (char const *name, off_t offset)
+{
+ char buf[UINTMAX_STRSIZE_BOUND];
+ int e = errno;
+ WARN ((0, e, _("%s: Warning: Cannot seek to %s"),
+ quotearg_colon (name),
+ STRINGIFY_BIGINT (offset, buf)));
+}
+
+void
+symlink_error (char const *contents, char const *name)
+{
+ int e = errno;
+ ERROR ((0, e, _("%s: Cannot create symlink to %s"),
+ quotearg_colon (name), quote_n (1, contents)));
+}
+
+void
+stat_error (char const *name)
+{
+ call_arg_error ("stat", name);
+}
+
+void
+stat_warn (char const *name)
+{
+ call_arg_warn ("stat", name);
+}
+
+void
+truncate_error (char const *name)
+{
+ call_arg_error ("truncate", name);
+}
+
+void
+truncate_warn (char const *name)
+{
+ call_arg_warn ("truncate", name);
+}
+
+void
+unlink_error (char const *name)
+{
+ call_arg_error ("unlink", name);
+}
+
+void
+utime_error (char const *name)
+{
+ call_arg_error ("utime", name);
+}
+
+void
+waitpid_error (char const *name)
+{
+ call_arg_error ("waitpid", name);
+}
+
+void
+write_error (char const *name)
+{
+ call_arg_error ("write", name);
+}
+
+void
+write_error_details (char const *name, ssize_t status, size_t size)
+{
+ if (status < 0)
+ write_error (name);
+ else
+ ERROR ((0, 0, _("%s: Wrote only %lu of %lu bytes"),
+ name, (unsigned long) status, (unsigned long) record_size));
+}
+
+void
+write_fatal (char const *name)
+{
+ call_arg_fatal ("write", name);
+}
+
+void
+write_fatal_details (char const *name, ssize_t status, size_t size)
+{
+ write_error_details (name, status, size);
+ fatal_exit ();
+}
+
+
+/* Fork, aborting if unsuccessful. */
+pid_t
+xfork (void)
+{
+ pid_t p = fork ();
+ if (p == (pid_t) -1)
+ call_arg_fatal ("fork", _("child process"));
+ return p;
+}
+
+/* Create a pipe, aborting if unsuccessful. */
+void
+xpipe (int fd[2])
+{
+ if (pipe (fd) < 0)
+ call_arg_fatal ("pipe", _("interprocess channel"));
+}
+
+/* Return an unambiguous printable representation, allocated in slot N,
+ for NAME, suitable for diagnostics. */
+char const *
+quote_n (int n, char const *name)
+{
+ return quotearg_n_style (n, locale_quoting_style, name);
+}
+
+/* Return an unambiguous printable representation of NAME, suitable
+ for diagnostics. */
+char const *
+quote (char const *name)
+{
+ return quote_n (0, name);
+}
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