/* `ln' program to create links between files.
- Copyright (C) 86, 89, 90, 91, 1995-2003 Free Software Foundation, Inc.
+ Copyright (C) 1986, 1989-1991, 1995-2006 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
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. */
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
\f
/* Written by Mike Parker and David MacKenzie. */
#include "backupfile.h"
#include "dirname.h"
#include "error.h"
+#include "filenamecat.h"
#include "quote.h"
+#include "yesno.h"
/* The official name of this program (e.g., no `g' prefix). */
#define PROGRAM_NAME "ln"
-#define AUTHORS N_ ("Mike Parker and David MacKenzie")
+#define AUTHORS "Mike Parker", "David MacKenzie"
#ifndef ENABLE_HARD_LINK_TO_SYMLINK_WARNING
# define ENABLE_HARD_LINK_TO_SYMLINK_WARNING 0
#endif
-/* For long options that have no equivalent short option, use a
- non-character as a pseudo short option, starting with CHAR_MAX + 1. */
-enum
-{
- TARGET_DIRECTORY_OPTION = CHAR_MAX + 1
-};
-
-int link (); /* Some systems don't declare this anywhere. */
-
-#ifdef S_ISLNK
-int symlink ();
-#endif
-
/* In being careful not even to try to make hard links to directories,
we have to know whether link(2) follows symlinks. If it does, then
we have to *stat* the `source' to see if the resulting link would be
lstat (File, Stat_buf)
#endif
-/* Construct a string NEW_DEST by concatenating DEST, a slash, and
- basename(SOURCE) in alloca'd memory. Don't modify DEST or SOURCE. */
-
-#define PATH_BASENAME_CONCAT(new_dest, dest, source) \
- do \
- { \
- const char *source_base; \
- char *tmp_source; \
- \
- tmp_source = (char *) alloca (strlen ((source)) + 1); \
- strcpy (tmp_source, (source)); \
- strip_trailing_slashes (tmp_source); \
- source_base = base_name (tmp_source); \
- \
- (new_dest) = (char *) alloca (strlen ((dest)) + 1 \
- + strlen (source_base) + 1); \
- stpcpy (stpcpy (stpcpy ((new_dest), (dest)), "/"), source_base);\
- } \
- while (0)
-
-int isdir ();
-int yesno ();
-
/* The name by which the program was run, for error messages. */
char *program_name;
/* FIXME: document */
-enum backup_type backup_type;
+static enum backup_type backup_type;
-/* A pointer to the function used to make links. This will point to either
- `link' or `symlink'. */
-static int (*linkfunc) ();
+/* If true, make symbolic links; otherwise, make hard links. */
+static bool symbolic_link;
-/* If nonzero, make symbolic links; otherwise, make hard links. */
-static int symbolic_link;
+/* If true, ask the user before removing existing files. */
+static bool interactive;
-/* If nonzero, ask the user before removing existing files. */
-static int interactive;
+/* If true, remove existing files unconditionally. */
+static bool remove_existing_files;
-/* If nonzero, remove existing files unconditionally. */
-static int remove_existing_files;
+/* If true, list each file as it is moved. */
+static bool verbose;
-/* If nonzero, list each file as it is moved. */
-static int verbose;
-
-/* If nonzero, allow the superuser to make hard links to directories. */
-static int hard_dir_link;
+/* If true, allow the superuser to *attempt* to make hard links
+ to directories. However, it appears that this option is not useful
+ in practice, since even the superuser is prohibited from hard-linking
+ directories on most (all?) existing systems. */
+static bool hard_dir_link;
/* If nonzero, and the specified destination is a symbolic link to a
directory, treat it just as if it were a directory. Otherwise, the
command `ln --force --no-dereference file symlink-to-dir' deletes
symlink-to-dir before creating the new link. */
-static int dereference_dest_dir_symlinks = 1;
+static bool dereference_dest_dir_symlinks = true;
static struct option const long_options[] =
{
{"backup", optional_argument, NULL, 'b'},
{"directory", no_argument, NULL, 'F'},
{"no-dereference", no_argument, NULL, 'n'},
+ {"no-target-directory", no_argument, NULL, 'T'},
{"force", no_argument, NULL, 'f'},
{"interactive", no_argument, NULL, 'i'},
{"suffix", required_argument, NULL, 'S'},
- {"target-directory", required_argument, NULL, TARGET_DIRECTORY_OPTION},
+ {"target-directory", required_argument, NULL, 't'},
{"symbolic", no_argument, NULL, 's'},
{"verbose", no_argument, NULL, 'v'},
- {"version-control", required_argument, NULL, 'V'}, /* Deprecated. FIXME. */
{GETOPT_HELP_OPTION_DECL},
{GETOPT_VERSION_OPTION_DECL},
{NULL, 0, NULL, 0}
};
+/* FILE is the last operand of this command. Return true if FILE is a
+ directory. But report an error there is a problem accessing FILE,
+ or if FILE does not exist but would have to refer to an existing
+ directory if it referred to anything at all. */
+
+static bool
+target_directory_operand (char const *file)
+{
+ char const *b = last_component (file);
+ size_t blen = strlen (b);
+ bool looks_like_a_dir = (blen == 0 || ISSLASH (b[blen - 1]));
+ struct stat st;
+ int err = ((dereference_dest_dir_symlinks ? stat : lstat) (file, &st) == 0
+ ? 0 : errno);
+ bool is_a_dir = !err && S_ISDIR (st.st_mode);
+ if (err && err != ENOENT)
+ error (EXIT_FAILURE, err, _("accessing %s"), quote (file));
+ if (is_a_dir < looks_like_a_dir)
+ error (EXIT_FAILURE, err, _("target %s is not a directory"), quote (file));
+ return is_a_dir;
+}
+
/* Make a link DEST to the (usually) existing file SOURCE.
Symbolic links to nonexistent files are allowed.
- If DEST is a directory, put the link to SOURCE in that directory.
- Return 1 if there is an error, otherwise 0. */
+ Return true if successful. */
-static int
+static bool
do_link (const char *source, const char *dest)
{
struct stat source_stats;
struct stat dest_stats;
char *dest_backup = NULL;
- int lstat_status;
- int backup_succeeded = 0;
+ bool lstat_ok = false;
+ bool source_is_dir = false;
+ bool ok;
/* Use stat here instead of lstat.
On SVR4, link does not follow symlinks, so this check disallows
if (STAT_LIKE_LINK (source, &source_stats) != 0)
{
error (0, errno, _("accessing %s"), quote (source));
- return 1;
+ return false;
}
if (ENABLE_HARD_LINK_TO_SYMLINK_WARNING
quote (source));
}
- if (!hard_dir_link && S_ISDIR (source_stats.st_mode))
+ if (S_ISDIR (source_stats.st_mode))
{
- error (0, 0, _("%s: hard link not allowed for directory"),
- quote (source));
- return 1;
+ source_is_dir = true;
+ if (! hard_dir_link)
+ {
+ error (0, 0, _("%s: hard link not allowed for directory"),
+ quote (source));
+ return false;
+ }
}
}
- lstat_status = lstat (dest, &dest_stats);
- if (lstat_status != 0 && errno != ENOENT)
- {
- error (0, errno, _("accessing %s"), quote (dest));
- return 1;
- }
-
- /* If the destination is a directory or (it is a symlink to a directory
- and the user has not specified --no-dereference), then form the
- actual destination name by appending base_name (source) to the
- specified destination directory. */
- if ((lstat_status == 0
- && S_ISDIR (dest_stats.st_mode))
-#ifdef S_ISLNK
- || (dereference_dest_dir_symlinks
- && (lstat_status == 0
- && S_ISLNK (dest_stats.st_mode)
- && isdir (dest)))
-#endif
- )
+ if (remove_existing_files || interactive || backup_type != no_backups)
{
- /* Target is a directory; build the full filename. */
- char *new_dest;
- PATH_BASENAME_CONCAT (new_dest, dest, source);
- dest = new_dest;
-
- /* Get stats for new DEST. */
- lstat_status = lstat (dest, &dest_stats);
- if (lstat_status != 0 && errno != ENOENT)
+ lstat_ok = (lstat (dest, &dest_stats) == 0);
+ if (!lstat_ok && errno != ENOENT)
{
error (0, errno, _("accessing %s"), quote (dest));
- return 1;
+ return false;
}
}
But if the source and destination are the same, don't remove
anything and fail right here. */
if (remove_existing_files
- && lstat_status == 0
+ && lstat_ok
/* Allow `ln -sf --backup k k' to succeed in creating the
self-referential symlink, but don't allow the hard-linking
equivalent: `ln -f k k' (with or without --backup) to get
beyond this point, because the error message you'd get is
misleading. */
- && (backup_type == none || !symbolic_link)
+ && (backup_type == no_backups || !symbolic_link)
&& (!symbolic_link || stat (source, &source_stats) == 0)
- && source_stats.st_dev == dest_stats.st_dev
- && source_stats.st_ino == dest_stats.st_ino
+ && SAME_INODE (source_stats, dest_stats)
/* The following detects whether removing DEST will also remove
SOURCE. If the file has only one link then both are surely
the same link. Otherwise check whether they point to the same
{
error (0, 0, _("%s and %s are the same file"),
quote_n (0, source), quote_n (1, dest));
- return 1;
+ return false;
}
- if (lstat_status == 0 || lstat (dest, &dest_stats) == 0)
+ if (lstat_ok)
{
if (S_ISDIR (dest_stats.st_mode))
{
error (0, 0, _("%s: cannot overwrite directory"), quote (dest));
- return 1;
+ return false;
}
if (interactive)
{
fprintf (stderr, _("%s: replace %s? "), program_name, quote (dest));
if (!yesno ())
- return 0;
- }
- else if (!remove_existing_files && backup_type == none)
- {
- error (0, 0, _("%s: File exists"), quote (dest));
- return 1;
+ return true;
+ remove_existing_files = true;
}
- if (backup_type != none)
+ if (backup_type != no_backups)
{
- char *tmp_backup = find_backup_file_name (dest, backup_type);
- if (tmp_backup == NULL)
- xalloc_die ();
- dest_backup = (char *) alloca (strlen (tmp_backup) + 1);
- strcpy (dest_backup, tmp_backup);
- free (tmp_backup);
- if (rename (dest, dest_backup))
+ dest_backup = find_backup_file_name (dest, backup_type);
+ if (rename (dest, dest_backup) != 0)
{
- if (errno != ENOENT)
+ int rename_errno = errno;
+ free (dest_backup);
+ dest_backup = NULL;
+ if (rename_errno != ENOENT)
{
- error (0, errno, _("cannot backup %s"), quote (dest));
- return 1;
+ error (0, rename_errno, _("cannot backup %s"), quote (dest));
+ return false;
}
- else
- dest_backup = NULL;
- }
- else
- {
- backup_succeeded = 1;
}
}
+ }
+
+ ok = ((symbolic_link ? symlink (source, dest) : link (source, dest))
+ == 0);
+
+ /* If the attempt to create a link failed and we are removing or
+ backing up destinations, unlink the destination and try again.
+
+ POSIX 1003.1-2004 requires that ln -f A B must unlink B even on
+ failure (e.g., when A does not exist). This is counterintuitive,
+ and we submitted a defect report
+ <http://www.opengroup.org/austin/mailarchives/ag-review/msg01794.html>
+ (2004-06-24). If the committee does not fix the standard we'll
+ have to change the behavior of ln -f, at least if POSIXLY_CORRECT
+ is set. In the meantime ln -f A B will not unlink B unless the
+ attempt to link A to B failed because B already existed.
- /* Try to unlink DEST even if we may have renamed it. In some unusual
- cases (when DEST and DEST_BACKUP are hard-links that refer to the
- same file), rename succeeds and DEST remains. If we didn't remove
- DEST in that case, the subsequent LINKFUNC call would fail. */
- if (unlink (dest) && errno != ENOENT)
+ Try to unlink DEST even if we may have backed it up successfully.
+ In some unusual cases (when DEST and DEST_BACKUP are hard-links
+ that refer to the same file), rename succeeds and DEST remains.
+ If we didn't remove DEST in that case, the subsequent LINKFUNC
+ call would fail. */
+
+ if (!ok && errno == EEXIST && (remove_existing_files || dest_backup))
+ {
+ if (unlink (dest) != 0)
{
error (0, errno, _("cannot remove %s"), quote (dest));
- return 1;
+ free (dest_backup);
+ return false;
}
- }
- else if (errno != ENOENT)
- {
- error (0, errno, _("accessing %s"), quote (dest));
- return 1;
- }
- if (verbose)
- {
- printf ((symbolic_link
- ? _("create symbolic link %s to %s")
- : _("create hard link %s to %s")),
- quote_n (0, dest), quote_n (1, source));
- if (backup_succeeded)
- printf (_(" (backup: %s)"), quote (dest_backup));
- putchar ('\n');
+ ok = ((symbolic_link ? symlink (source, dest) : link (source, dest))
+ == 0);
}
- if ((*linkfunc) (source, dest) == 0)
+ if (ok)
{
- return 0;
+ if (verbose)
+ {
+ if (dest_backup)
+ printf ("%s ~ ", quote (dest_backup));
+ printf ("%s %c> %s\n", quote_n (0, dest), (symbolic_link ? '-' : '='),
+ quote_n (1, source));
+ }
}
-
- error (0, errno,
- (symbolic_link
- ? _("creating symbolic link %s to %s")
- : _("creating hard link %s to %s")),
- quote_n (0, dest), quote_n (1, source));
-
- if (dest_backup)
+ else
{
- if (rename (dest_backup, dest))
- error (0, errno, _("cannot un-backup %s"), quote (dest));
+ error (0, errno,
+ (symbolic_link
+ ? (errno != ENAMETOOLONG && *source
+ ? _("creating symbolic link %s")
+ : _("creating symbolic link %s -> %s"))
+ : (errno == EMLINK && !source_is_dir
+ ? _("creating hard link to %.0s%s")
+ : (errno == EDQUOT || errno == EEXIST || errno == ENOSPC
+ || errno == EROFS)
+ ? _("creating hard link %s")
+ : _("creating hard link %s => %s"))),
+ quote_n (0, dest), quote_n (1, source));
+
+ if (dest_backup)
+ {
+ if (rename (dest_backup, dest) != 0)
+ error (0, errno, _("cannot un-backup %s"), quote (dest));
+ }
}
- return 1;
+
+ free (dest_backup);
+ return ok;
}
void
usage (int status)
{
- if (status != 0)
+ if (status != EXIT_SUCCESS)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("\
-Usage: %s [OPTION]... TARGET [LINK_NAME]\n\
- or: %s [OPTION]... TARGET... DIRECTORY\n\
- or: %s [OPTION]... --target-directory=DIRECTORY TARGET...\n\
+Usage: %s [OPTION]... [-T] TARGET LINK_NAME (1st form)\n\
+ or: %s [OPTION]... TARGET (2nd form)\n\
+ or: %s [OPTION]... TARGET... DIRECTORY (3rd form)\n\
+ or: %s [OPTION]... -t DIRECTORY TARGET... (4th form)\n\
"),
- program_name, program_name, program_name);
+ program_name, program_name, program_name, program_name);
fputs (_("\
-Create a link to the specified TARGET with optional LINK_NAME.\n\
-If LINK_NAME is omitted, a link with the same basename as the TARGET is\n\
-created in the current directory. When using the second form with more\n\
-than one TARGET, the last argument must be a directory; create links\n\
-in DIRECTORY to each TARGET. Create hard links by default, symbolic\n\
-links with --symbolic. When creating hard links, each TARGET must exist.\n\
+In the 1st form, create a link to TARGET with the name LINK_NAME.\n\
+In the 2nd form, create a link to TARGET in the current directory.\n\
+In the 3rd and 4th forms, create links to each TARGET in DIRECTORY.\n\
+Create hard links by default, symbolic links with --symbolic.\n\
+When creating hard links, each TARGET must exist.\n\
\n\
"), stdout);
fputs (_("\
fputs (_("\
--backup[=CONTROL] make a backup of each existing destination file\n\
-b like --backup but does not accept an argument\n\
- -d, -F, --directory hard link directories (super-user only)\n\
+ -d, -F, --directory allow the superuser to attempt to hard link\n\
+ directories (note: will probably fail due to\n\
+ system restrictions, even for the superuser)\n\
-f, --force remove existing destination files\n\
"), stdout);
fputs (_("\
"), stdout);
fputs (_("\
-S, --suffix=SUFFIX override the usual backup suffix\n\
- --target-directory=DIRECTORY specify the DIRECTORY in which to create\n\
+ -t, --target-directory=DIRECTORY specify the DIRECTORY in which to create\n\
the links\n\
- -v, --verbose print name of each file before linking\n\
+ -T, --no-target-directory treat LINK_NAME as a normal file\n\
+ -v, --verbose print name of each linked file\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
main (int argc, char **argv)
{
int c;
- int errors;
- int make_backups = 0;
+ bool ok;
+ bool make_backups = false;
char *backup_suffix_string;
char *version_control_string = NULL;
- char *target_directory = NULL;
- int target_directory_specified;
- unsigned int n_files;
+ char const *target_directory = NULL;
+ bool no_target_directory = false;
+ int n_files;
char **file;
- int dest_is_dir;
initialize_main (&argc, &argv);
program_name = argv[0];
backup_suffix_string = getenv ("SIMPLE_BACKUP_SUFFIX");
symbolic_link = remove_existing_files = interactive = verbose
- = hard_dir_link = 0;
- errors = 0;
+ = hard_dir_link = false;
- while ((c = getopt_long (argc, argv, "bdfinsvFS:V:", long_options, NULL))
+ while ((c = getopt_long (argc, argv, "bdfinst:vFS:T", long_options, NULL))
!= -1)
{
switch (c)
{
- case 0: /* Long-named option. */
- break;
-
- case 'V': /* FIXME: this is deprecated. Remove it in 2001. */
- error (0, 0,
- _("warning: --version-control (-V) is obsolete; support for\
- it\nwill be removed in some future release. Use --backup=%s instead."
- ), optarg);
- /* Fall through. */
-
case 'b':
- make_backups = 1;
+ make_backups = true;
if (optarg)
version_control_string = optarg;
break;
case 'd':
case 'F':
- hard_dir_link = 1;
+ hard_dir_link = true;
break;
case 'f':
- remove_existing_files = 1;
- interactive = 0;
+ remove_existing_files = true;
+ interactive = false;
break;
case 'i':
- remove_existing_files = 0;
- interactive = 1;
+ remove_existing_files = false;
+ interactive = true;
break;
case 'n':
- dereference_dest_dir_symlinks = 0;
+ dereference_dest_dir_symlinks = false;
break;
case 's':
#ifdef S_ISLNK
- symbolic_link = 1;
+ symbolic_link = true;
#else
error (EXIT_FAILURE, 0,
_("symbolic links are not supported on this system"));
#endif
break;
- case TARGET_DIRECTORY_OPTION:
+ case 't':
+ if (target_directory)
+ error (EXIT_FAILURE, 0, _("multiple target directories specified"));
+ else
+ {
+ struct stat st;
+ if (stat (optarg, &st) != 0)
+ error (EXIT_FAILURE, errno, _("accessing %s"), quote (optarg));
+ if (! S_ISDIR (st.st_mode))
+ error (EXIT_FAILURE, 0, _("target %s is not a directory"),
+ quote (optarg));
+ }
target_directory = optarg;
break;
+ case 'T':
+ no_target_directory = true;
+ break;
case 'v':
- verbose = 1;
+ verbose = true;
break;
case 'S':
- make_backups = 1;
+ make_backups = true;
backup_suffix_string = optarg;
break;
case_GETOPT_HELP_CHAR;
}
}
- if (argc <= optind)
- {
- error (0, 0, _("missing file argument"));
- usage (EXIT_FAILURE);
- }
-
n_files = argc - optind;
file = argv + optind;
- target_directory_specified = (target_directory != NULL);
- if (!target_directory)
- target_directory = file[n_files - 1];
-
- /* If target directory is not specified, and there's only one
- file argument, then pretend `.' was given as the second argument. */
- if (!target_directory_specified && n_files == 1)
+ if (n_files <= 0)
{
- static char *dummy[2];
- dummy[0] = file[0];
- dummy[1] = ".";
- file = dummy;
- n_files = 2;
- dest_is_dir = 1;
+ error (0, 0, _("missing file operand"));
+ usage (EXIT_FAILURE);
}
- else
+
+ if (no_target_directory)
{
- dest_is_dir = isdir (target_directory);
+ if (target_directory)
+ error (EXIT_FAILURE, 0,
+ _("Cannot combine --target-directory "
+ "and --no-target-directory"));
+ if (n_files != 2)
+ {
+ if (n_files < 2)
+ error (0, 0,
+ _("missing destination file operand after %s"),
+ quote (file[0]));
+ else
+ error (0, 0, _("extra operand %s"), quote (file[2]));
+ usage (EXIT_FAILURE);
+ }
}
-
- if (symbolic_link)
- linkfunc = symlink;
- else
- linkfunc = link;
-
- if (target_directory_specified && !dest_is_dir)
+ else if (!target_directory)
{
- error (0, 0, _("%s: specified target directory is not a directory"),
- quote (target_directory));
- usage (EXIT_FAILURE);
+ if (n_files < 2)
+ target_directory = ".";
+ else if (2 <= n_files && target_directory_operand (file[n_files - 1]))
+ target_directory = file[--n_files];
+ else if (2 < n_files)
+ error (EXIT_FAILURE, 0, _("target %s is not a directory"),
+ quote (file[n_files - 1]));
}
if (backup_suffix_string)
backup_type = (make_backups
? xget_version (_("backup type"), version_control_string)
- : none);
-
- if (target_directory_specified || n_files > 2)
- {
- unsigned int i;
- unsigned int last_file_idx = (target_directory_specified
- ? n_files - 1
- : n_files - 2);
+ : no_backups);
- if (!target_directory_specified && !dest_is_dir)
- error (EXIT_FAILURE, 0,
- _("when making multiple links, last argument must be a directory"));
- for (i = 0; i <= last_file_idx; ++i)
- errors += do_link (file[i], target_directory);
- }
- else
+ if (target_directory)
{
- struct stat source_stats;
- const char *source;
- char *dest;
- char *new_dest;
-
- source = file[0];
- dest = file[1];
-
- /* When the destination is specified with a trailing slash and the
- source exists but is not a directory, convert the user's command
- `ln source dest/' to `ln source dest/basename(source)'. */
-
- if (dest[strlen (dest) - 1] == '/'
- && lstat (source, &source_stats) == 0
- && !S_ISDIR (source_stats.st_mode))
- {
- PATH_BASENAME_CONCAT (new_dest, dest, source);
- }
- else
+ int i;
+ ok = true;
+ for (i = 0; i < n_files; ++i)
{
- new_dest = dest;
+ char *dest_base;
+ char *dest = file_name_concat (target_directory,
+ last_component (file[i]),
+ &dest_base);
+ strip_trailing_slashes (dest_base);
+ ok &= do_link (file[i], dest);
+ free (dest);
}
-
- errors = do_link (source, new_dest);
}
+ else
+ ok = do_link (file[0], file[1]);
- exit (errors != 0);
+ exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
}
projects / platform / upstream / coreutils.git / blobdiff