From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dSmaM-0004D7-Sm for barebox@lists.infradead.org; Wed, 05 Jul 2017 15:51:33 +0000 Message-ID: <1499269829.22075.31.camel@pengutronix.de> From: Lucas Stach Date: Wed, 05 Jul 2017 17:50:29 +0200 In-Reply-To: <20170703131729.12055-1-abbotti@mev.co.uk> References: <20170703131729.12055-1-abbotti@mev.co.uk> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] readlink: Improve -f handling To: Ian Abbott Cc: barebox@lists.infradead.org Am Montag, den 03.07.2017, 14:17 +0100 schrieb Ian Abbott: > 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 Applied, thanks. > --- > commands/readlink.c | 19 ++++++++++++------- > 1 file changed, 12 insertions(+), 7 deletions(-) > > diff --git a/commands/readlink.c b/commands/readlink.c > index a19c8e004..2dfa56667 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) _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox