uuidgen: add -c for compact uuid

It generates the uuid string but without the hyphen

MFC After:		3 days
Reviews by:		tcberner
Differential Revision:	https://reviews.freebsd.org/D38820

2 files changed, 35 insertions, 3 deletions

diff --git a/bin/uuidgen/uuidgen.1 b/bin/uuidgen/uuidgen.1
index 83326e3a189a..75fd02703175 100644
--- a/bin/uuidgen/uuidgen.1
+++ b/bin/uuidgen/uuidgen.1
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 23, 2012
+.Dd March 1, 2024
 .Dt UUIDGEN 1
 .Os
 .Sh NAME
@@ -34,6 +34,7 @@
 .Nm
 .Op Fl 1
 .Op Fl r
+.Op Fl c
 .Op Fl n Ar count
 .Op Fl o Ar filename
 .Sh DESCRIPTION
@@ -53,6 +54,8 @@ instructs
 to not generate them in batch, but one at a time.
 .It Fl r
 This option controls creation of random UUID (version 4).
+.It Fl c
+This options contols creation of compact UUID (without hyphen).
 .It Fl n
 This option controls the number of identifiers generated.
 By default, multiple identifiers are generated in batch.
diff --git a/bin/uuidgen/uuidgen.c b/bin/uuidgen/uuidgen.c
index 061907f57109..6dcfdde92a5f 100644
--- a/bin/uuidgen/uuidgen.c
+++ b/bin/uuidgen/uuidgen.c
@@ -46,6 +46,31 @@ usage(void)
 	exit(1);
 }
 
+static void
+uuid_to_compact_string(const uuid_t *u, char **s, uint32_t *status)
+{
+	uuid_t nil;
+
+	if (status != NULL)
+		*status = uuid_s_ok;
+
+	if (s == NULL)
+		return;
+
+	if (u == NULL) {
+		u = &nil;
+		uuid_create_nil(&nil, NULL);
+	}
+
+	asprintf(s, "%08x%04x%04x%02x%02x%02x%02x%02x%02x%02x%02x",
+	    u->time_low, u->time_mid, u->time_hi_and_version,
+	    u->clock_seq_hi_and_reserved, u->clock_seq_low, u->node[0],
+	    u->node[1], u->node[2], u->node[3], u->node[4], u->node[5]);
+
+	if (*s == NULL && status != NULL)
+		*status = uuid_s_no_memory;
+}
+
 static int
 uuidgen_v4(struct uuid *store, int count)
 {
@@ -85,16 +110,20 @@ main(int argc, char *argv[])
 	uuid_t *store, *uuid;
 	char *p;
 	int ch, count, i, iterate, status, version;
+	void (*tostring)(const uuid_t *, char **, uint32_t *) = uuid_to_string;
 
 	count = -1;  /* no count yet */
 	fp = stdout; /* default output file */
 	iterate = 0; /* not one at a time */
 	version = 1; /* create uuid v1 by default */
-	while ((ch = getopt(argc, argv, "1rn:o:")) != -1)
+	while ((ch = getopt(argc, argv, "1crn:o:")) != -1)
 		switch (ch) {
 		case '1':
 			iterate = 1;
 			break;
+		case 'c':
+			tostring = uuid_to_compact_string;
+			break;
 		case 'r':
 			version = 4;
 			break;
@@ -162,7 +191,7 @@ main(int argc, char *argv[])
 
 	uuid = store;
 	while (count--) {
-		uuid_to_string(uuid++, &p, &status);
+		tostring(uuid++, &p, &status);
 		if (status != uuid_s_ok)
 			err(1, "cannot stringify a UUID");
 		fprintf(fp, "%s\n", p);