From a05a326b0cd7c4146e60ea4d66440d4a28dfb41a Mon Sep 17 00:00:00 2001 From: =?utf8?q?P=C3=A1draig=20Brady?=
Date: Wed, 12 Dec 2012 19:54:12 +0000
Subject: [PATCH] readlink: support multiple command line arguments
This allows efficient processing of multiple files,
while also increasing compatibility with BSD's readlink(1).
We also add the -z, --zero option to delimit output items
with the NUL character which disambiguates output in the
presence of '\n' characters.
* src/readlink.c (usage): Add the --zero description,
and also adjust the description of --no-newline accordingly.
(main): Handle the -z option and iterate over multiple arguments.
Also as in commit v8.15-24-g9d46b25 we use fputs() and putchar()
rather than printf() for performance reasons.
* doc/coreutils.texi (readlink invocation): Document the
new --zero option, adjust the --no-newline description, and
tweak the general info to indicate multiple files are supported.
* tests/readlink/multi.sh: A new test for the new functionality.
* tests/local.mk: Reference the new test.
* man/readlink.x: Adjust the summary and also reference realpath.
* NEWS: Mention the improvement.
* THANKS.in: Suggested by Aaron Davies.
---
NEWS | 3 +++
THANKS.in | 1 +
doc/coreutils.texi | 15 +++++++++----
man/readlink.x | 4 ++--
src/readlink.c | 60 +++++++++++++++++++++++++++----------------------
tests/local.mk | 1 +
tests/readlink/multi.sh | 46 +++++++++++++++++++++++++++++++++++++
7 files changed, 97 insertions(+), 33 deletions(-)
create mode 100755 tests/readlink/multi.sh
diff --git a/NEWS b/NEWS
index 1ee2c17..e4472df 100644
--- a/NEWS
+++ b/NEWS
@@ -61,6 +61,9 @@ GNU coreutils NEWS -*- outline -*-
** Improvements
+ readlink now supports multiple arguments, and a complementary
+ -z, --zero option to delimit output items with the NUL character.
+
stat and tail now know about CEPH. stat -f --format=%T now reports the file
system type, and tail -f uses polling for files on CEPH file systems.
diff --git a/THANKS.in b/THANKS.in
index 9009795..c2651e7 100644
--- a/THANKS.in
+++ b/THANKS.in
@@ -14,6 +14,7 @@ note to the bug-report mailing list (as seen at end of e.g., cp --help).
??? kytek@cybercomm.net
A Costa agcosta@gis.net
+Aaron Davies aaron.davies@gmail.com
Aaron Hawley ashawley@uvm.edu
Achim Blumensath blume@corona.oche.de
Adam Jimerson vendion@charter.net
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 5f8fad7..0646f82 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -9737,20 +9737,20 @@ Set the default SELinux security context to be used for created files.
@item Readlink mode
-@command{readlink} outputs the value of the given symbolic link.
+@command{readlink} outputs the value of the given symbolic links.
If @command{readlink} is invoked with an argument other than the name
of a symbolic link, it produces no output and exits with a nonzero exit code.
@item Canonicalize mode
-@command{readlink} outputs the absolute name of the given file which contains
+@command{readlink} outputs the absolute name of the given files which contain
no @file{.}, @file{..} components nor any repeated separators
(@file{/}) or symbolic links.
@end table
@example
-readlink [@var{option}] @var{file}
+readlink [@var{option}]@dots{} @var{file}@dots{}
@end example
By default, @command{readlink} operates in readlink mode.
@@ -9789,7 +9789,8 @@ as a directory.
@itemx --no-newline
@opindex -n
@opindex --no-newline
-Do not output the trailing newline.
+Do not print the output delimiter, when a single @var{file} is specified.
+Print a warning if specified along with multiple @var{file}s.
@item -s
@itemx -q
@@ -9807,6 +9808,12 @@ Suppress most error messages.
@opindex --verbose
Report error messages.
+@item -z
+@itemx --zero
+@opindex -z
+@opindex --zero
+Separate output items with @sc{nul} characters.
+
@end table
The @command{readlink} utility first appeared in OpenBSD 2.1.
diff --git a/man/readlink.x b/man/readlink.x
index 79ba758..6b28bca 100644
--- a/man/readlink.x
+++ b/man/readlink.x
@@ -1,6 +1,6 @@
[NAME]
-readlink \- print value of a symbolic link or canonical file name
+readlink \- print resolved symbolic links or canonical file names
[DESCRIPTION]
.\" Add any additional description here
[SEE ALSO]
-readlink(2)
+readlink(2), realpath(1), realpath(3)
diff --git a/src/readlink.c b/src/readlink.c
index e025bf9..ff7d67f 100644
--- a/src/readlink.c
+++ b/src/readlink.c
@@ -25,7 +25,6 @@
#include "canonicalize.h"
#include "error.h"
#include "areadlink.h"
-#include "quote.h"
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "readlink"
@@ -47,6 +46,7 @@ static struct option const longopts[] =
{"quiet", no_argument, NULL, 'q'},
{"silent", no_argument, NULL, 's'},
{"verbose", no_argument, NULL, 'v'},
+ {"zero", no_argument, NULL, 'z'},
{GETOPT_HELP_OPTION_DECL},
{GETOPT_VERSION_OPTION_DECL},
{NULL, 0, NULL, 0}
@@ -59,7 +59,7 @@ usage (int status)
emit_try_help ();
else
{
- printf (_("Usage: %s [OPTION]... FILE\n"), program_name);
+ printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
fputs (_("Print value of a symbolic link or canonical file name\n\n"),
stdout);
fputs (_("\
@@ -77,10 +77,11 @@ usage (int status)
every component of the given name recursively,\
\n\
without requirements on components existence\n\
- -n, --no-newline do not output the trailing newline\n\
+ -n, --no-newline do not output the trailing delimiter\n\
-q, --quiet,\n\
-s, --silent suppress most error messages\n\
-v, --verbose report error messages\n\
+ -z, --zero separate output with NUL rather than newline\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
@@ -94,14 +95,9 @@ main (int argc, char **argv)
{
/* If not -1, use this method to canonicalize. */
int can_mode = -1;
-
- /* File name to canonicalize. */
- const char *fname;
-
- /* Result of canonicalize. */
- char *value;
-
+ int status = EXIT_SUCCESS;
int optc;
+ bool use_nuls = false;
initialize_main (&argc, &argv);
set_program_name (argv[0]);
@@ -111,7 +107,7 @@ main (int argc, char **argv)
atexit (close_stdout);
- while ((optc = getopt_long (argc, argv, "efmnqsv", longopts, NULL)) != -1)
+ while ((optc = getopt_long (argc, argv, "efmnqsvz", longopts, NULL)) != -1)
{
switch (optc)
{
@@ -134,6 +130,9 @@ main (int argc, char **argv)
case 'v':
verbose = true;
break;
+ case 'z':
+ use_nuls = true;
+ break;
case_GETOPT_HELP_CHAR;
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
default:
@@ -147,26 +146,33 @@ main (int argc, char **argv)
usage (EXIT_FAILURE);
}
- fname = argv[optind++];
-
- if (optind < argc)
+ if (argc - optind > 1)
{
- error (0, 0, _("extra operand %s"), quote (argv[optind]));
- usage (EXIT_FAILURE);
+ if (no_newline)
+ error (0, 0, _("ignoring --no-newline with multiple arguments"));
+ no_newline = false;
}
- value = (can_mode != -1
- ? canonicalize_filename_mode (fname, can_mode)
- : areadlink_with_size (fname, 63));
- if (value)
+ for (; optind < argc; ++optind)
{
- printf ("%s%s", value, (no_newline ? "" : "\n"));
- free (value);
- return EXIT_SUCCESS;
+ const char *fname = argv[optind];
+ char *value = (can_mode != -1
+ ? canonicalize_filename_mode (fname, can_mode)
+ : areadlink_with_size (fname, 63));
+ if (value)
+ {
+ fputs (value, stdout);
+ if (! no_newline)
+ putchar (use_nuls ? '\0' : '\n');
+ free (value);
+ }
+ else
+ {
+ status = EXIT_FAILURE;
+ if (verbose)
+ error (0, errno, "%s", fname);
+ }
}
- if (verbose)
- error (EXIT_FAILURE, errno, "%s", fname);
-
- return EXIT_FAILURE;
+ return status;
}
diff --git a/tests/local.mk b/tests/local.mk
index 5eeddd5..efdd896 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -602,6 +602,7 @@ all_tests = \
tests/readlink/can-e.sh \
tests/readlink/can-f.sh \
tests/readlink/can-m.sh \
+ tests/readlink/multi.sh \
tests/readlink/rl-1.sh \
tests/rmdir/fail-perm.sh \
tests/rmdir/ignore.sh \
diff --git a/tests/readlink/multi.sh b/tests/readlink/multi.sh
new file mode 100755
index 0000000..877cce6
--- /dev/null
+++ b/tests/readlink/multi.sh
@@ -0,0 +1,46 @@
+#!/bin/sh
+# test multiple argument handling.
+
+# Copyright (C) 2012 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 3 of the License, 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, see