sfdisk: add --output <list> for print command(s)

Signed-off-by: Karel Zak <kzak@redhat.com>

disk-utils/sfdisk.8

@@ -108,15 +108,18 @@ backup file name is ~/sfdisk-<device>-<offset>.bak, see \fI\-\-backup-file\fR.
 .BR \-f , " \-\-force"
 Disable all consistency checking.
 .TP
+.BR \-o , " \-\-output " \fIlist\fP
+Specify which output columns to print.  Use
+.B \-\-help
+to get a list of all supported columns.
+
+The default list of columns may be extended if \fIlist\fP is
+specified in the format \fI+list\fP (e.g. \fB-o +UUID\fP).
+.TP
 .BR \-O , " \-\-backup-file " \fIpath\fR
 Override default backup file name. Note that the device name and offset is always
 appended to the file name.
 .TP
-.BR \-X , " \-\-label \fItype\fR
-Specify disk label type (e.g. dos, gpt, ...). If no label specified then sfdisk
-defaults to an existing label. If there is no label on the device than defaults
-to "dos".
-.TP
 .BR \-q , " \-\-quiet"
 Suppress extra info messages.
 .TP
@@ -133,6 +136,11 @@ Deprecated option. The sector unit is supported only.
 Deprecated and ignored option. Linux (and another moder OS) compatible
 partitioning is the default.
 .TP
+.BR \-X , " \-\-label \fItype\fR
+Specify disk label type (e.g. dos, gpt, ...). If no label specified then sfdisk
+defaults to an existing label. If there is no label on the device than defaults
+to "dos".
+.TP
 .BR \-h , " \-\-help"
 Display help text and exit.
 .TP

disk-utils/sfdisk.c

@@ -1306,6 +1306,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
 	fputs(_(" -A, --append              append partitions to existing partition table\n"), out);
 	fputs(_(" -b, --backup              backup partition table sectors (see -O)\n"), out);
 	fputs(_(" -f, --force               disable all consistency checking\n"), out);
+	fputs(_(" -o, --output <list>       output columns\n"), out);
 	fputs(_(" -O, --backup-file <path>  override default backout file name\n"), out);
 	fputs(_(" -N, --partno <num>        specify partition number\n"), out);
 	fputs(_(" -X, --label <name>        specify label type (dos, gpt, ...)\n"), out);
@@ -1320,6 +1321,8 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
 	fputs(USAGE_HELP, out);
 	fputs(USAGE_VERSION, out);
 
+	list_available_columns(out);
+
 	fprintf(out, USAGE_MAN_TAIL("sfdisk(8)"));
 	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
 }
@@ -1327,6 +1330,7 @@ static void __attribute__ ((__noreturn__)) usage(FILE *out)
 
 int main(int argc, char *argv[])
 {
+	const char *outarg = NULL;
 	int rc = -EINVAL, c, longidx = -1;
 	struct sfdisk _sf = {
 		.partno = -1
@@ -1356,6 +1360,7 @@ int main(int argc, char *argv[])
 		{ "list-types", no_argument,	NULL, 'T' },
 		{ "no-act",  no_argument,       NULL, 'n' },
 		{ "no-reread", no_argument,     NULL, OPT_NOREREAD },
+		{ "output",  required_argument, NULL, 'o' },
 		{ "partno",  required_argument, NULL, 'N' },
 		{ "show-size", no_argument,	NULL, 's' },
 		{ "show-geometry", no_argument, NULL, 'g' },
@@ -1383,7 +1388,7 @@ int main(int argc, char *argv[])
 	textdomain(PACKAGE);
 	atexit(close_stdout);
 
-	while ((c = getopt_long(argc, argv, "aAbcdfghlLO:nN:qsTu:vVX:",
+	while ((c = getopt_long(argc, argv, "aAbcdfghlLo:O:nN:qsTu:vVX:",
 					longopts, &longidx)) != -1) {
 		switch(c) {
 		case 'a':
@@ -1423,6 +1428,9 @@ int main(int argc, char *argv[])
 		case 'L':
 			warnx(_("--Linux option is unnecessary and deprecated"));
 			break;
+		case 'o':
+			outarg = optarg;
+			break;
 		case 'O':
 			sf->backup = 1;
 			sf->backup_file = optarg;
@@ -1481,6 +1489,8 @@ int main(int argc, char *argv[])
 	}
 
 	sfdisk_init(sf);
+	if (outarg)
+		init_fields(NULL, outarg, NULL);
 
 	if (sf->verify && !sf->act)
 		sf->act = ACT_VERIFY;	/* --verify make be used with --list too */