qemu-img: Improve error messages

Previously, when there is a user error in argv parsing, qemu-img prints
help text and exits.

Add an error_exit function to print a helpful error message and a hint
to run 'qemu-img --help' for more information.

As a bonus, "qemu-img <cmd> --help" now has a more reasonable exit code
0.

In the future the help text should be split by sub command, and only
print the information for the specified command.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2014-04-22 13:36:11 +08:00 committed by Kevin Wolf
parent 90d9d30152
commit ac1307abfe

View file

@ -57,8 +57,22 @@ static void format_print(void *opaque, const char *name)
printf(" %s", name);
}
static void QEMU_NORETURN GCC_FMT_ATTR(1, 2) error_exit(const char *fmt, ...)
{
va_list ap;
error_printf("qemu-img: ");
va_start(ap, fmt);
error_vprintf(fmt, ap);
va_end(ap);
error_printf("\nTry 'qemu-img --help' for more information\n");
exit(EXIT_FAILURE);
}
/* Please keep in synch with qemu-img.texi */
static void help(void)
static void QEMU_NORETURN help(void)
{
const char *help_msg =
"qemu-img version " QEMU_VERSION ", Copyright (c) 2004-2008 Fabrice Bellard\n"
@ -129,7 +143,7 @@ static void help(void)
printf("%s\nSupported formats:", help_msg);
bdrv_iterate_format(format_print, NULL);
printf("\n");
exit(1);
exit(EXIT_SUCCESS);
}
static int GCC_FMT_ATTR(2, 3) qprintf(bool quiet, const char *fmt, ...)
@ -399,7 +413,7 @@ static int img_create(int argc, char **argv)
}
if (optind >= argc) {
help();
error_exit("Expecting image file name");
}
optind++;
@ -422,7 +436,7 @@ static int img_create(int argc, char **argv)
img_size = (uint64_t)sval;
}
if (optind != argc) {
help();
error_exit("Unexpected argument: %s", argv[optind]);
}
bdrv_img_create(filename, fmt, base_filename, base_fmt,
@ -591,7 +605,8 @@ static int img_check(int argc, char **argv)
} else if (!strcmp(optarg, "all")) {
fix = BDRV_FIX_LEAKS | BDRV_FIX_ERRORS;
} else {
help();
error_exit("Unknown option value for -r "
"(expecting 'leaks' or 'all'): %s", optarg);
}
break;
case OPTION_OUTPUT:
@ -603,7 +618,7 @@ static int img_check(int argc, char **argv)
}
}
if (optind != argc - 1) {
help();
error_exit("Expecting one image file name");
}
filename = argv[optind++];
@ -714,7 +729,7 @@ static int img_commit(int argc, char **argv)
}
}
if (optind != argc - 1) {
help();
error_exit("Expecting one image file name");
}
filename = argv[optind++];
@ -960,7 +975,7 @@ static int img_compare(int argc, char **argv)
if (optind != argc - 2) {
help();
error_exit("Expecting two image file names");
}
filename1 = argv[optind++];
filename2 = argv[optind++];
@ -1276,7 +1291,7 @@ static int img_convert(int argc, char **argv)
}
if (bs_n < 1) {
help();
error_exit("Must specify image file name");
}
@ -1886,7 +1901,7 @@ static int img_info(int argc, char **argv)
}
}
if (optind != argc - 1) {
help();
error_exit("Expecting one image file name");
}
filename = argv[optind++];
@ -2050,10 +2065,10 @@ static int img_map(int argc, char **argv)
break;
}
}
if (optind >= argc) {
help();
if (optind != argc - 1) {
error_exit("Expecting one image file name");
}
filename = argv[optind++];
filename = argv[optind];
if (output && !strcmp(output, "json")) {
output_format = OFORMAT_JSON;
@ -2142,7 +2157,7 @@ static int img_snapshot(int argc, char **argv)
return 0;
case 'l':
if (action) {
help();
error_exit("Cannot mix '-l', '-a', '-c', '-d'");
return 0;
}
action = SNAPSHOT_LIST;
@ -2150,7 +2165,7 @@ static int img_snapshot(int argc, char **argv)
break;
case 'a':
if (action) {
help();
error_exit("Cannot mix '-l', '-a', '-c', '-d'");
return 0;
}
action = SNAPSHOT_APPLY;
@ -2158,7 +2173,7 @@ static int img_snapshot(int argc, char **argv)
break;
case 'c':
if (action) {
help();
error_exit("Cannot mix '-l', '-a', '-c', '-d'");
return 0;
}
action = SNAPSHOT_CREATE;
@ -2166,7 +2181,7 @@ static int img_snapshot(int argc, char **argv)
break;
case 'd':
if (action) {
help();
error_exit("Cannot mix '-l', '-a', '-c', '-d'");
return 0;
}
action = SNAPSHOT_DELETE;
@ -2179,7 +2194,7 @@ static int img_snapshot(int argc, char **argv)
}
if (optind != argc - 1) {
help();
error_exit("Expecting one image file name");
}
filename = argv[optind++];
@ -2292,8 +2307,11 @@ static int img_rebase(int argc, char **argv)
progress = 0;
}
if ((optind != argc - 1) || (!unsafe && !out_baseimg)) {
help();
if (optind != argc - 1) {
error_exit("Expecting one image file name");
}
if (!unsafe && !out_baseimg) {
error_exit("Must specify backing file (-b) or use unsafe mode (-u)");
}
filename = argv[optind++];
@ -2553,7 +2571,7 @@ static int img_resize(int argc, char **argv)
/* Remove size from argv manually so that negative numbers are not treated
* as options by getopt. */
if (argc < 3) {
help();
error_exit("Not enough arguments");
return 1;
}
@ -2580,7 +2598,7 @@ static int img_resize(int argc, char **argv)
}
}
if (optind != argc - 1) {
help();
error_exit("Expecting one image file name");
}
filename = argv[optind++];
@ -2697,7 +2715,7 @@ static int img_amend(int argc, char **argv)
}
if (!options) {
help();
error_exit("Must specify options (-o)");
}
filename = (optind == argc - 1) ? argv[argc - 1] : NULL;
@ -2709,7 +2727,7 @@ static int img_amend(int argc, char **argv)
}
if (optind != argc - 1) {
help();
error_exit("Expecting one image file name");
}
bs = bdrv_new_open("image", filename, fmt,
@ -2781,8 +2799,9 @@ int main(int argc, char **argv)
qemu_init_main_loop();
bdrv_init();
if (argc < 2)
help();
if (argc < 2) {
error_exit("Not enough arguments");
}
cmdname = argv[1];
argc--; argv++;
@ -2794,6 +2813,5 @@ int main(int argc, char **argv)
}
/* not found */
help();
return 0;
error_exit("Command not found: %s", cmdname);
}