X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fopt%2Fusage.c;h=f321ed2949a8bfb7cd5cdbce5955780dba1cd233;hp=b7381bc7378c6673c742d6dc23b0c42f211e8265;hb=af7afcd46e70e87397c33408d88f2bedd2c90bd8;hpb=be6a5cdadeef4995cc935f2d2443f45f542ed125

diff --git a/ccan/opt/usage.c b/ccan/opt/usage.c
index b7381bc7..f321ed29 100644
--- a/ccan/opt/usage.c
+++ b/ccan/opt/usage.c
@@ -1,3 +1,4 @@
+/* Licensed under GPLv3+ - see LICENSE file for details */
 #include <ccan/opt/opt.h>
 #include <string.h>
 #include <stdlib.h>
@@ -28,6 +29,17 @@ char *opt_usage(const char *argv0, const char *extra)
 	unsigned int i, num, len;
 	char *ret, *p;
 
+	if (!extra) {
+		extra = "";
+		for (i = 0; i < opt_count; i++) {
+			if (opt_table[i].cb == (void *)opt_usage_and_exit
+			    && opt_table[i].u.carg) {
+				extra = opt_table[i].u.carg;
+				break;
+			}
+		}
+	}
+
 	/* An overestimate of our length. */
 	len = strlen("Usage: %s ") + strlen(argv0)
 		+ strlen("[-%.*s]") + opt_num_short + 1
@@ -82,14 +94,14 @@ char *opt_usage(const char *argv0, const char *extra)
 			len += sprintf(p + len, " <arg>");
 		len += sprintf(p + len, "%.*s",
 			       len < strlen(OPT_SPACE_PAD)
-			       ? strlen(OPT_SPACE_PAD) - len : 1,
+			       ? (unsigned)strlen(OPT_SPACE_PAD) - len : 1,
 			       OPT_SPACE_PAD);
 
 		len += sprintf(p + len, "%s", opt_table[i].desc);
 		if (opt_table[i].show) {
 			char buf[OPT_SHOW_LEN + sizeof("...")];
 			strcpy(buf + OPT_SHOW_LEN, "...");
-			opt_table[i].show(buf, opt_table[i].arg);
+			opt_table[i].show(buf, opt_table[i].u.arg);
 			len += sprintf(p + len, " (default: %s)", buf);
 		}
 		p += len;