blkid: add -L -U options (evaluation API)

Signed-off-by: root <root@nb.net.home>

diff --git a/libs/blkid/bin/blkid.c b/libs/blkid/bin/blkid.c
index 6b2c0a73b535d10ce9e6528662ba96d13caa3dc9..3d29d03cb5f04849403f88656cd393338b9c5a2b 100644 (file)
--- a/libs/blkid/bin/blkid.c
+++ b/libs/blkid/bin/blkid.c
@@ -54,8 +54,9 @@ static void usage(int error)
        print_version(out);
        fprintf(out,
                "Usage:\n"
+               "  %1$s -L <label> | -U <uuid>\n\n"
                "  %1$s [-c <file>] [-ghlLv] [-o format] [-s <tag>] \n"
-               "         [-t <token>] [-w <file>] [dev ...]\n\n"
+               "        [-t <token>] [-w <file>] [dev ...]\n\n"
                "  %1$s -p [-O <offset>] [-S <size>] [-o format] <dev> [dev ...]\n\n"
                "Options:\n"
                "  -c <file>   cache file (default: /etc/blkid.tab, /dev/null = none)\n"
@@ -66,6 +67,8 @@ static void usage(int error)
                "  -s <tag>    show specified tag(s) (default show all tags)\n"
                "  -t <token>  find device with a specific token (NAME=value pair)\n"
                "  -l          lookup the the first device with arguments specified by -t\n"
+               "  -L <label>  convert LABEL to device name\n"
+               "  -U <uuid>   convert UUID to device name\n"
                "  -v          print version and exit\n"
                "  -w <file>   write cache to different file (/dev/null = no write)\n"
                "  <dev>       specify device(s) to probe (default: all devices)\n\n"
@@ -370,11 +373,11 @@ int main(int argc, char **argv)
        int err = 4;
        unsigned int i;
        int output_format = 0;
-       int lookup = 0, gc = 0, lowprobe = 0;
+       int lookup = 0, gc = 0, lowprobe = 0, eval = 0;
        int c;
        blkid_loff_t offset = 0, size = 0;
 
-       while ((c = getopt (argc, argv, "c:f:ghlo:O:ps:S:t:w:v")) != EOF)
+       while ((c = getopt (argc, argv, "c:f:ghlL:o:O:ps:S:t:U:w:v")) != EOF)
                switch (c) {
                case 'c':
                        if (optarg && !*optarg)
@@ -384,6 +387,16 @@ int main(int argc, char **argv)
                        if (!write)
                                write = read;
                        break;
+               case 'L':
+                       eval++;
+                       search_value = strdup(optarg);
+                       search_type = strdup("LABEL");
+                       break;
+               case 'U':
+                       eval++;
+                       search_value = strdup(optarg);
+                       search_type = strdup("UUID");
+                       break;
                case 'l':
                        lookup++;
                        break;
@@ -460,7 +473,14 @@ int main(int argc, char **argv)
                goto exit;
        }
 
-       if (!lowprobe && blkid_get_cache(&cache, read) < 0)
+       /* convert LABEL/UUID lookup to evaluate request */
+       if (lookup && output_format == OUTPUT_DEVICE_ONLY && search_type &&
+           (!strcmp(search_type, "LABEL") || !strcmp(search_type, "UUID"))) {
+               eval++;
+               lookup = 0;
+       }
+
+       if (!lowprobe && !eval && blkid_get_cache(&cache, read) < 0)
                goto exit;
 
        err = 2;
@@ -472,6 +492,9 @@ int main(int argc, char **argv)
                pretty_print_dev(NULL);
 
        if (lowprobe) {
+               /*
+                * Low-level API
+                */
                blkid_probe pr;
 
                if (!numdev) {
@@ -490,7 +513,17 @@ int main(int argc, char **argv)
                        err += lowprobe_device(pr, devices[i],
                                        output_format, offset, size);
                blkid_free_probe(pr);
+       } else if (eval) {
+               /*
+                * Evaluate API
+                */
+               char *res = blkid_evaluate_spec(search_type, search_value, NULL);
+               if (res)
+                       printf("%s\n", res);
        } else if (lookup) {
+               /*
+                * Classic (cache based) API
+                */
                blkid_dev dev;
 
                if (!search_type) {
@@ -540,11 +573,9 @@ int main(int argc, char **argv)
        }
 
 exit:
-       if (search_type)
-               free(search_type);
-       if (search_value)
-               free(search_value);
-       if (!lowprobe)
+       free(search_type);
+       free(search_value);
+       if (!lowprobe && !eval)
                blkid_put_cache(cache);
        return err;
 }