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authorPádraig Brady <P@draigBrady.com>2011-12-27 00:30:23 +0000
committerPádraig Brady <P@draigBrady.com>2012-01-03 11:36:32 +0000
commit77ea441f79aa115f79b47d9c1fc9c0004c5c7111 (patch)
tree8228c30cde49ff735ca71b2ef9044a1ef833fe36 /src
parent76352c770e37de94140e0df4534462ff553c798b (diff)
downloadcoreutils-77ea441f79aa115f79b47d9c1fc9c0004c5c7111.tar.xz
realpath: a new program to print the resolved path
This program is compatible with other realpath(1) implementations, and also incorporates relpath like support, through the --relative options. The relpath support was suggested by Peng Yu, who also provided an initial implemenation of that functionality. * AUTHORS: Add my name. * NEWS: Mention the new command. * README: Likewise. * doc/coreutils.texi (realpath invocation): Add realpath info. * man/Makefile.am (realpath.1): Add dependency. * man/realpath.x: New template. * man/.gitignore: Ignore generated man page. * po/POTFILES.in: Add src/realpath.c. * src/.gitignore: Exclude realpath. * src/Makefile.am (EXTRA_PROGRAMS): Add realpath. * src/realpath.c: New file. * scripts/git-hooks/commit-msg: Add realpath to the list of prefixes. * tests/Makefile.am (TESTS): Add misc/realpath. * tests/misc/realpath: New file.
Diffstat (limited to 'src')
-rw-r--r--src/.gitignore1
-rw-r--r--src/Makefile.am3
-rw-r--r--src/realpath.c329
3 files changed, 333 insertions, 0 deletions
diff --git a/src/.gitignore b/src/.gitignore
index d25a8e57b..9c4c9b717 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -68,6 +68,7 @@ printf
ptx
pwd
readlink
+realpath
rm
rmdir
runcon
diff --git a/src/Makefile.am b/src/Makefile.am
index 6e0b3ae2d..db3159f7d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -97,6 +97,7 @@ EXTRA_PROGRAMS = \
ptx \
pwd \
readlink \
+ realpath \
rm \
rmdir \
runcon \
@@ -248,6 +249,7 @@ printf_LDADD = $(LDADD)
ptx_LDADD = $(LDADD)
pwd_LDADD = $(LDADD)
readlink_LDADD = $(LDADD)
+realpath_LDADD = $(LDADD)
rm_LDADD = $(LDADD)
rmdir_LDADD = $(LDADD)
runcon_LDADD = $(LDADD)
@@ -373,6 +375,7 @@ du_LDADD += $(LIBICONV)
getlimits_LDADD += $(LIBICONV)
printf_LDADD += $(LIBICONV)
ptx_LDADD += $(LIBICONV)
+realpath_LDADD += $(LIBICONV)
split_LDADD += $(LIBICONV)
stdbuf_LDADD += $(LIBICONV)
timeout_LDADD += $(LIBICONV)
diff --git a/src/realpath.c b/src/realpath.c
new file mode 100644
index 000000000..cb0ef2f1f
--- /dev/null
+++ b/src/realpath.c
@@ -0,0 +1,329 @@
+/* realpath - print the resolved path
+ Copyright (C) 2011-2012 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 <http://www.gnu.org/licenses/>. */
+
+/* Written by Pádraig Brady. */
+
+#include <config.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include "system.h"
+#include "canonicalize.h"
+#include "error.h"
+#include "quote.h"
+
+/* The official name of this program (e.g., no `g' prefix). */
+#define PROGRAM_NAME "realpath"
+
+#define AUTHORS proper_name_utf8 ("Padraig Brady", "P\303\241draig Brady")
+
+enum
+{
+ RELATIVE_TO_OPTION = CHAR_MAX + 1,
+ RELATIVE_BASE_OPTION
+};
+
+static bool verbose = true;
+static bool logical;
+static bool use_nuls;
+static const char *can_relative_to;
+static const char *can_relative_base;
+
+static struct option const longopts[] =
+{
+ {"canonicalize-existing", no_argument, NULL, 'e'},
+ {"canonicalize-missing", no_argument, NULL, 'm'},
+ {"relative-to", required_argument, NULL, RELATIVE_TO_OPTION},
+ {"relative-base", required_argument, NULL, RELATIVE_BASE_OPTION},
+ {"quiet", no_argument, NULL, 'q'},
+ {"strip", no_argument, NULL, 's' /* FIXME: deprecate in 2013 or so */},
+ {"no-symlinks", no_argument, NULL, 's'},
+ {"zero", no_argument, NULL, 'z'},
+ {"logical", no_argument, NULL, 'L'},
+ {"physical", no_argument, NULL, 'P'},
+ {GETOPT_HELP_OPTION_DECL},
+ {GETOPT_VERSION_OPTION_DECL},
+ {NULL, 0, NULL, 0}
+};
+
+void
+usage (int status)
+{
+ if (status != EXIT_SUCCESS)
+ fprintf (stderr, _("Try `%s --help' for more information.\n"),
+ program_name);
+ else
+ {
+ printf (_("Usage: %s [OPTION]... FILE...\n"), program_name);
+ fputs (_("\
+Print the resolved absolute file name;\n\
+all but the last component must exist\n\
+\n\
+"), stdout);
+ fputs (_("\
+ -e, --canonicalize-existing all components of the path must exist\n\
+ -m, --canonicalize-missing no components of the path need exist\n\
+ -L, --logical resolve `..' components before symlinks\n\
+ -P, --physical resolve symlinks as encountered (default)\n\
+ -q, --quiet suppress most error messages\n\
+ --relative-to=FILE print the resolved path relative to FILE\n\
+ --relative-base=FILE print absolute paths unless paths below FILE\n\
+ -s, --strip, --no-symlinks don't expand symlinks\n\
+ -z, --zero separate output with NUL rather than newline\n\
+\n\
+"), stdout);
+ fputs (HELP_OPTION_DESCRIPTION, stdout);
+ fputs (VERSION_OPTION_DESCRIPTION, stdout);
+ emit_ancillary_info ();
+ }
+ exit (status);
+}
+
+/* A wrapper around canonicalize_filename_mode(),
+ to call it twice when in LOGICAL mode. */
+static char *
+realpath_canon (const char *fname, int can_mode)
+{
+ char *can_fname = canonicalize_filename_mode (fname, can_mode);
+ if (logical && can_fname) /* canonicalize again to resolve symlinks. */
+ {
+ can_mode &= ~CAN_NOLINKS;
+ char *can_fname2 = canonicalize_filename_mode (can_fname, can_mode);
+ free (can_fname);
+ return can_fname2;
+ }
+ return can_fname;
+}
+
+/* Test whether prefix is parent or match of path. */
+static bool _GL_ATTRIBUTE_PURE
+path_prefix (const char *prefix, const char *path)
+{
+ while (*prefix && *path)
+ {
+ if (*prefix != *path)
+ break;
+ prefix++;
+ path++;
+ }
+ return (!*prefix && (*path == '/' || !*path));
+}
+
+/* Return the length of the longest common prefix
+ of PATH1 and PATH2, ensuring only full path components
+ are matched. Return 0 on no match. */
+static int _GL_ATTRIBUTE_PURE
+path_common_prefix (const char *path1, const char *path2)
+{
+ int i = 0;
+ int ret = 0;
+
+ while (*path1 && *path2)
+ {
+ if (*path1 != *path2)
+ break;
+ if (*path1 == '/')
+ ret = i;
+ path1++;
+ path2++;
+ i++;
+ }
+
+ if (!*path1 && !*path2)
+ ret = i;
+ if (!*path1 && *path2 == '/')
+ ret = i;
+ if (!*path2 && *path1 == '/')
+ ret = i;
+
+ return ret;
+}
+
+/* Output the relative representation if requested. */
+static bool
+relpath (const char *can_fname)
+{
+ if (can_relative_to)
+ {
+ /* Enforce --relative-base. */
+ if (can_relative_base)
+ {
+ if (!path_prefix (can_relative_base, can_fname)
+ || !path_prefix (can_relative_base, can_relative_to))
+ return false;
+ }
+
+ /* Skip the prefix common to --relative-to and path. */
+ int common_index = path_common_prefix (can_relative_to, can_fname);
+ const char *relto_suffix = can_relative_to + common_index;
+ const char *fname_suffix = can_fname + common_index;
+
+ /* Replace remaining components of --relative-to with '..', to get
+ to a common directory. Then output the remainder of fname. */
+ if (*relto_suffix)
+ {
+ ++relto_suffix;
+ printf ("%s", "..");
+ for (; *relto_suffix; ++relto_suffix)
+ {
+ if (*relto_suffix == '/')
+ printf ("%s", "/..");
+ }
+
+ printf ("%s", fname_suffix);
+ }
+ else
+ {
+ if (*fname_suffix)
+ printf ("%s", ++fname_suffix);
+ else
+ printf ("%c", '.');
+ }
+
+ putchar (use_nuls ? '\0' : '\n');
+
+ return true;
+ }
+
+ return false;
+}
+
+static bool
+isdir (const char *path)
+{
+ struct stat sb;
+ if (stat (path, &sb) != 0)
+ error (EXIT_FAILURE, errno, _("cannot stat %s"), quote (path));
+ return S_ISDIR (sb.st_mode);
+}
+
+static bool
+process_path (const char *fname, int can_mode)
+{
+ char *can_fname = realpath_canon (fname, can_mode);
+ if (!can_fname)
+ {
+ if (verbose)
+ error (0, errno, "%s", quote (fname));
+ return false;
+ }
+
+ if (!relpath (can_fname))
+ printf ("%s%c", can_fname, (use_nuls ? '\0' : '\n'));
+
+ free (can_fname);
+
+ return true;
+}
+
+int
+main (int argc, char **argv)
+{
+ bool ok = true;
+ int can_mode = CAN_ALL_BUT_LAST;
+ const char *relative_to = NULL;
+ const char *relative_base = NULL;
+
+ initialize_main (&argc, &argv);
+ set_program_name (argv[0]);
+ setlocale (LC_ALL, "");
+ bindtextdomain (PACKAGE, LOCALEDIR);
+ textdomain (PACKAGE);
+
+ atexit (close_stdout);
+
+ while (1)
+ {
+ int c = getopt_long (argc, argv, "eLmPqsz", longopts, NULL);
+ if (c == -1)
+ break;
+ switch (c)
+ {
+ case 'e':
+ can_mode &= ~CAN_MODE_MASK;
+ can_mode |= CAN_EXISTING;
+ break;
+ case 'm':
+ can_mode &= ~CAN_MODE_MASK;
+ can_mode |= CAN_MISSING;
+ break;
+ case 'L':
+ can_mode |= CAN_NOLINKS;
+ logical = true;
+ break;
+ case 's':
+ can_mode |= CAN_NOLINKS;
+ logical = false;
+ break;
+ case 'P':
+ can_mode &= ~CAN_NOLINKS;
+ logical = false;
+ break;
+ case 'q':
+ verbose = false;
+ break;
+ case 'z':
+ use_nuls = true;
+ break;
+ case RELATIVE_TO_OPTION:
+ relative_to = optarg;
+ break;
+ case RELATIVE_BASE_OPTION:
+ relative_base = optarg;
+ break;
+ case_GETOPT_HELP_CHAR;
+ case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
+ default:
+ usage (EXIT_FAILURE);
+ }
+ }
+
+ if (optind >= argc)
+ {
+ error (0, 0, _("missing operand"));
+ usage (EXIT_FAILURE);
+ }
+
+ if (relative_base && !relative_to)
+ {
+ error (0, 0, _("--relative-base requires --relative-to"));
+ usage (EXIT_FAILURE);
+ }
+
+ bool need_dir = (can_mode & CAN_MODE_MASK) == CAN_EXISTING;
+ if (relative_to)
+ {
+ can_relative_to = realpath_canon (relative_to, can_mode);
+ if (!can_relative_to)
+ error (EXIT_FAILURE, errno, "%s", quote (relative_to));
+ if (need_dir && !isdir (can_relative_to))
+ error (EXIT_FAILURE, ENOTDIR, "%s", quote (relative_to));
+ }
+ if (relative_base)
+ {
+ can_relative_base = realpath_canon (relative_base, can_mode);
+ if (!can_relative_base)
+ error (EXIT_FAILURE, errno, "%s", quote (relative_base));
+ if (need_dir && !isdir (can_relative_base))
+ error (EXIT_FAILURE, ENOTDIR, "%s", quote (relative_base));
+ }
+
+ for (; optind < argc; ++optind)
+ ok &= process_path (argv[optind], can_mode);
+
+ exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
+}