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| author | Ian Abbott <abbotti@mev.co.uk> | 2017-07-03 14:17:29 +0100 |
|---|---|---|
| committer | Lucas Stach <l.stach@pengutronix.de> | 2017-07-06 14:42:45 +0200 |
| commit | a6f379599227835114e4e2d8bf53f1a1c65d7fec (patch) | |
| tree | 23ed3f3343729c5669b78c2d50166fe8052459a9 /commands | |
| parent | f4563213084baa6c5271a9967b4c3b2bd6b2d49d (diff) | |
| download | barebox-a6f379599227835114e4e2d8bf53f1a1c65d7fec.tar.gz barebox-a6f379599227835114e4e2d8bf53f1a1c65d7fec.tar.xz | |
readlink: Improve -f handling
For `readlink -f FILE VARIABLE`, set VARIABLE to the absolute, canonical
file name of FILE by following symbolic links. All but the final
component of FILE must exist.
Prior to commit a602bebcf7e4 ("fs: Implement links to directories") the
above worked in the limited case where FILE was an absolute path, the
final component was a symbolic link, and all preceding components were
directories. If FILE was a relative path with the final component being
a symbolic link, and all preceding paths being directories, the command
sort of worked, but produced a relative path as the result. Both of
these cases were broken by the above commit.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Diffstat (limited to 'commands')
| -rw-r--r-- | commands/readlink.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/commands/readlink.c b/commands/readlink.c index a19c8e0041..2dfa566675 100644 --- a/commands/readlink.c +++ b/commands/readlink.c @@ -44,17 +44,21 @@ static int do_readlink(int argc, char *argv[]) if (argc < optind + 2) return COMMAND_ERROR_USAGE; - if (readlink(argv[optind], realname, PATH_MAX - 1) < 0) - goto err; - if (canonicalize) { - char *buf = canonicalize_path(realname); + char *buf = canonicalize_path(argv[optind]); + struct stat s; if (!buf) goto err; + if (stat(dirname(argv[optind]), &s) || !S_ISDIR(s.st_mode)) { + free(buf); + goto err; + } setenv(argv[optind + 1], buf); free(buf); } else { + if (readlink(argv[optind], realname, PATH_MAX - 1) < 0) + goto err; setenv(argv[optind + 1], realname); } @@ -65,15 +69,16 @@ err: } BAREBOX_CMD_HELP_START(readlink) -BAREBOX_CMD_HELP_TEXT("Read value of a symbolic link and store it into VARIABLE.") +BAREBOX_CMD_HELP_TEXT("Read value of a symbolic link or canonical file name and store it into VARIABLE.") BAREBOX_CMD_HELP_TEXT("") BAREBOX_CMD_HELP_TEXT("Options:") -BAREBOX_CMD_HELP_OPT ("-f", "canonicalize by following first symlink"); +BAREBOX_CMD_HELP_OPT("-f", "canonicalize by following symlinks;") +BAREBOX_CMD_HELP_OPT("", "final component need not exist"); BAREBOX_CMD_HELP_END BAREBOX_CMD_START(readlink) .cmd = do_readlink, - BAREBOX_CMD_DESC("read value of a symbolic link") + BAREBOX_CMD_DESC("read value of a symbolic link or canonical file name") BAREBOX_CMD_OPTS("[-f] FILE VARIABLE") BAREBOX_CMD_GROUP(CMD_GRP_FILE) BAREBOX_CMD_HELP(cmd_readlink_help) |