[PATCH] commands: readlink: print to stdout if variable is missing
Ahmad Fatoum
a.fatoum at pengutronix.de
Thu Jan 16 06:10:57 PST 2025
For easier interactive use during debugging or when the shell is
exercised by Labgrid, teach the readlink command to directly output to
stdout instead of an environment variable if none was specified.
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
commands/Kconfig | 6 ++++--
commands/readlink.c | 39 +++++++++++++++++++++++++++++----------
2 files changed, 33 insertions(+), 12 deletions(-)
diff --git a/commands/Kconfig b/commands/Kconfig
index 448a6e240cad..ecbcabd0272d 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -1084,9 +1084,11 @@ config CMD_READLINK
help
Read value of a symbolic link
- Usage: readlink [-f] FILE VARIABLE
+ Usage: readlink [-f] FILE [VARIABLE]
- Read value of a symbolic link and store it into VARIABLE.
+ Read value of a symbolic link or canonical file name
+ The value is either stored it into the specified VARIABLE
+ or printed.
Options:
-f canonicalize by following first symlink
diff --git a/commands/readlink.c b/commands/readlink.c
index 55f8249028e1..a37b6d7512d7 100644
--- a/commands/readlink.c
+++ b/commands/readlink.c
@@ -11,9 +11,19 @@
#include <malloc.h>
#include <getopt.h>
+static void output_result(const char *var, const char *val)
+{
+ if (var)
+ setenv(var, val);
+ else
+ printf("%s\n", val);
+
+}
+
static int do_readlink(int argc, char *argv[])
{
- char realname[PATH_MAX];
+ const char *var;
+ char *path, realname[PATH_MAX];
int canonicalize = 0;
int opt;
@@ -27,35 +37,44 @@ static int do_readlink(int argc, char *argv[])
}
}
- if (argc < optind + 2)
+ argv += optind;
+ argc -= optind;
+
+ if (argc == 0 || argc > 2)
return COMMAND_ERROR_USAGE;
+ path = argv[0];
+ var = argv[1];
+
if (canonicalize) {
- char *buf = canonicalize_path(AT_FDCWD, argv[optind]);
+ char *buf = canonicalize_path(AT_FDCWD, path);
struct stat s;
if (!buf)
goto err;
- if (stat(dirname(argv[optind]), &s) || !S_ISDIR(s.st_mode)) {
+ if (stat(dirname(path), &s) || !S_ISDIR(s.st_mode)) {
free(buf);
goto err;
}
- setenv(argv[optind + 1], buf);
+ output_result(var, buf);
free(buf);
} else {
- if (readlink(argv[optind], realname, PATH_MAX - 1) < 0)
+ if (readlink(path, realname, PATH_MAX - 1) < 0)
goto err;
- setenv(argv[optind + 1], realname);
+ output_result(var, realname);
}
return 0;
err:
- unsetenv(argv[optind + 1]);
+ if (var)
+ unsetenv(var);
return 1;
}
BAREBOX_CMD_HELP_START(readlink)
-BAREBOX_CMD_HELP_TEXT("Read value of a symbolic link or canonical file name and store it into VARIABLE.")
+BAREBOX_CMD_HELP_TEXT("Read value of a symbolic link or canonical file name")
+BAREBOX_CMD_HELP_TEXT("The value is either stored it into the specified VARIABLE")
+BAREBOX_CMD_HELP_TEXT("or printed.")
BAREBOX_CMD_HELP_TEXT("")
BAREBOX_CMD_HELP_TEXT("Options:")
BAREBOX_CMD_HELP_OPT("-f", "canonicalize by following symlinks;")
@@ -65,7 +84,7 @@ BAREBOX_CMD_HELP_END
BAREBOX_CMD_START(readlink)
.cmd = do_readlink,
BAREBOX_CMD_DESC("read value of a symbolic link or canonical file name")
- BAREBOX_CMD_OPTS("[-f] FILE VARIABLE")
+ BAREBOX_CMD_OPTS("[-f] FILE [VARIABLE]")
BAREBOX_CMD_GROUP(CMD_GRP_FILE)
BAREBOX_CMD_HELP(cmd_readlink_help)
BAREBOX_CMD_END
--
2.39.5
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