Add an nvme_function structure array, defining the name, C function and

usage message for each nvmecontrol command.  This helps reduce some code
clutter both now and for future commits which will add logpage and
firmware support to nvmecontrol(8).

Also move helper function prototypes to the end of the header file, after
the per-command functions.

Sponsored by:	Intel
MFC after:	3 days

2 files changed, 32 insertions, 16 deletions

diff --git a/sbin/nvmecontrol/nvmecontrol.c b/sbin/nvmecontrol/nvmecontrol.c
index f0ecb2f..af5e148 100644
--- a/sbin/nvmecontrol/nvmecontrol.c
+++ b/sbin/nvmecontrol/nvmecontrol.c
@@ -44,14 +44,31 @@ __FBSDID("$FreeBSD$");
 
 #include "nvmecontrol.h"
 
+typedef void (*nvme_fn_t)(int argc, char *argv[]);
+
+struct nvme_function {
+	const char	*name;
+	nvme_fn_t	fn;
+	const char	*usage;
+} funcs[] = {
+	{"devlist",	devlist,	DEVLIST_USAGE},
+	{"identify",	identify,	IDENTIFY_USAGE},
+	{"perftest",	perftest,	PERFTEST_USAGE},
+	{"reset",	reset,		RESET_USAGE},
+	{NULL,		NULL,		NULL},
+};
+
 static void
 usage(void)
 {
+	struct nvme_function *f;
+
+	f = funcs;
 	fprintf(stderr, "usage:\n");
-	fprintf(stderr, DEVLIST_USAGE);
-	fprintf(stderr, IDENTIFY_USAGE);
-	fprintf(stderr, RESET_USAGE);
-	fprintf(stderr, PERFTEST_USAGE);
+	while (f->name != NULL) {
+		fprintf(stderr, "%s", f->usage);
+		f++;
+	}
 	exit(EX_USAGE);
 }
 
@@ -136,18 +153,17 @@ open_dev(const char *str, int *fd, int show_error, int exit_on_error)
 int
 main(int argc, char *argv[])
 {
+	struct nvme_function *f;
 
 	if (argc < 2)
 		usage();
 
-	if (strcmp(argv[1], "devlist") == 0)
-		devlist(argc-1, &argv[1]);
-	else if (strcmp(argv[1], "identify") == 0)
-		identify(argc-1, &argv[1]);
-	else if (strcmp(argv[1], "perftest") == 0)
-		perftest(argc-1, &argv[1]);
-	else if (strcmp(argv[1], "reset") == 0)
-		reset(argc-1, &argv[1]);
+	f = funcs;
+	while (f->name != NULL) {
+		if (strcmp(argv[1], f->name) == 0)
+			f->fn(argc-1, &argv[1]);
+		f++;
+	}
 
 	usage();
 
diff --git a/sbin/nvmecontrol/nvmecontrol.h b/sbin/nvmecontrol/nvmecontrol.h
index 74430f9..ec61e95 100644
--- a/sbin/nvmecontrol/nvmecontrol.h
+++ b/sbin/nvmecontrol/nvmecontrol.h
@@ -46,14 +46,14 @@
 #define RESET_USAGE							       \
 "       nvmecontrol reset <controller id>\n"
 
-int open_dev(const char *str, int *fd, int show_error, int exit_on_error);
-void read_controller_data(int fd, struct nvme_controller_data *cdata);
-void read_namespace_data(int fd, int nsid, struct nvme_namespace_data *nsdata);
-
 void devlist(int argc, char *argv[]);
 void identify(int argc, char *argv[]);
 void perftest(int argc, char *argv[]);
 void reset(int argc, char *argv[]);
 
+int open_dev(const char *str, int *fd, int show_error, int exit_on_error);
+void read_controller_data(int fd, struct nvme_controller_data *cdata);
+void read_namespace_data(int fd, int nsid, struct nvme_namespace_data *nsdata);
+
 #endif