Process command-line arguments to print partition name, file system

type, or partition flags. An optional disk device of interest may also
be provided by the user.

Author: lucasvr

src/partinfo.c

@@ -8,17 +8,89 @@
 #include <stdio.h>
 #include <parted/parted.h>
 
-int main(int argc, char **argv)
+typedef enum {
+	OP_NONE,
+	OP_FLAGS,
+	OP_FSTYPE,
+	OP_NAME
+} op_t;
+
+void usage(char *programname, int exit_code)
+{
+	printf("Syntax: %s <option> [disk]\n\n", programname);
+	printf("Available options are:\n"
+			"  --flags         print partition flags\n"
+			"  --fstype        print partition file system type\n"
+			"  --name          print partition name\n"
+			"\n");
+	exit(exit_code);
+}
+
+size_t print_flags(PedPartition *part, char *buf, size_t n, size_t left)
 {
 	PedPartitionFlag flag = 0;
+	size_t count = 0;
+
+	while ((flag = ped_partition_flag_next(flag))) {
+		if (ped_partition_get_flag(part, flag) && left > 0) {
+			size_t bytecount = snprintf(&buf[n], left, "%s,", ped_partition_flag_get_name(flag));
+			count += bytecount;
+			left -= bytecount;
+			n += bytecount;
+		}
+	}
+	if (buf[n-1] == ',')
+		buf[n-1] = '\0';
+	return count;
+}
+
+size_t print_fstype(PedPartition *part, char *buf, size_t n, size_t left)
+{
+	const PedFileSystemType *fstype = part->fs_type;
+	size_t count = 0;
+
+	if (fstype && fstype->name)
+		count = snprintf(&buf[n], left, "%s", fstype->name);
+	return count;
+}
+
+size_t print_name(PedPartition *part, char *buf, size_t n, size_t left)
+{
+	const PedDiskType *disktype = part->disk->type;
+	const char *name;
+	size_t count = 0;
+
+	if (disktype && disktype->name && !strcasecmp(disktype->name, "msdos")) {
+		/* msdos partition tables don't support labeling partition */
+		return 0;
+	}
+	name = ped_partition_get_name(part);
+	if (name)
+		count += snprintf(&buf[n], left, "%s", name);
+	return count;
+}
+
+int main(int argc, char **argv)
+{
 	PedPartition *part = NULL;
 	PedDevice *dev = NULL;
 	PedDisk *disk = NULL;
 	char *user_dev;
-	char buf[128];
-	size_t n = 0, left = sizeof(buf) - 1;
+	op_t op = OP_NONE;
 
-	user_dev = argc > 1 ? argv[1] : NULL;
+	if (argc == 1)
+		usage(argv[0], 1);
+	else if (! strcasecmp(argv[1], "--flags"))
+		op = OP_FLAGS;
+	else if (! strcasecmp(argv[1], "--fstype"))
+		op = OP_FSTYPE;
+	else if (! strcasecmp(argv[1], "--name"))
+		op = OP_NAME;
+	else {
+		printf("Invalid option '%s'\n\n", argv[1]);
+		usage(argv[0], 1);
+	}
+	user_dev = argc > 2 ? argv[2] : NULL;
 
 	ped_device_probe_all();
 	while ((dev = ped_device_get_next(dev))) {
@@ -28,21 +100,22 @@ int main(int argc, char **argv)
 		while ((part = ped_disk_next_partition(disk, part))) {
 			if (part->num < 0)
 				continue;
+
+			char buf[512];
 			memset(buf, 0, sizeof(buf));
+			size_t n = 0, left = sizeof(buf) - 1;
+
 			n += snprintf(buf, left, "%s%d:", dev->path, part->num);
 			left -= n;
-			while ((flag = ped_partition_flag_next(flag))) {
-				if (ped_partition_get_flag(part, flag) && left > 0) {
-					n += snprintf(&buf[n], left, "%s,", ped_partition_flag_get_name(flag));
-					left -= n;
-				}
-			}
-			if (buf[n-1] == ',')
-				buf[n-1] = '\0';
+
+			if (op == OP_FLAGS)
+				print_flags(part, buf, n, left);
+			else if (op == OP_FSTYPE)
+				print_fstype(part, buf, n, left);
+			else if (op == OP_NAME)
+				print_name(part, buf, n, left);
+
 			printf("%s\n", buf);
-			left = sizeof(buf) - 1;
-			flag = 0;
-			n = 0;
 		}
 		part = NULL;
 		ped_disk_destroy(disk);