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-rw-r--r--misc/e2label.c121
1 files changed, 121 insertions, 0 deletions
diff --git a/misc/e2label.c b/misc/e2label.c
new file mode 100644
index 0000000..910ccc7
--- /dev/null
+++ b/misc/e2label.c
@@ -0,0 +1,121 @@
+/*
+ * e2label.c - Print or change the volume label on an ext2 fs
+ *
+ * Written by Andries Brouwer (aeb@cwi.nl), 970714
+ *
+ * Copyright 1997, 1998 by Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Public
+ * License.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <termios.h>
+#include <time.h>
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#else
+extern char *optarg;
+extern int optind;
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#include "support/nls-enable.h"
+
+#define EXT2_SUPER_MAGIC 0xEF53
+
+#define VOLNAMSZ 16
+
+struct ext2_super_block {
+ char s_dummy0[56];
+ unsigned char s_magic[2];
+ char s_dummy1[62];
+ char s_volume_name[VOLNAMSZ];
+ char s_last_mounted[64];
+ char s_dummy2[824];
+} sb;
+
+static int open_e2fs (char *dev, int mode)
+{
+ int fd;
+
+ fd = open(dev, mode);
+ if (fd < 0) {
+ perror(dev);
+ fprintf (stderr, _("e2label: cannot open %s\n"), dev);
+ exit(1);
+ }
+ if (lseek(fd, 1024, SEEK_SET) != 1024) {
+ perror(dev);
+ fprintf (stderr, _("e2label: cannot seek to superblock\n"));
+ exit(1);
+ }
+ if (read(fd, (char *) &sb, sizeof(sb)) != sizeof(sb)) {
+ perror(dev);
+ fprintf (stderr, _("e2label: error reading superblock\n"));
+ exit(1);
+ }
+ if (sb.s_magic[0] + 256*sb.s_magic[1] != EXT2_SUPER_MAGIC) {
+ fprintf (stderr, _("e2label: not an ext2 filesystem\n"));
+ exit(1);
+ }
+
+ return fd;
+}
+
+static void print_label (char *dev)
+{
+ char label[VOLNAMSZ+1];
+
+ open_e2fs (dev, O_RDONLY);
+ snprintf(label, sizeof(label), "%.*s", EXT2_LEN_STR(sb.s_volume_name));
+ label[VOLNAMSZ] = 0;
+ printf("%s\n", label);
+}
+
+static void change_label (char *dev, char *label)
+{
+ int fd;
+
+ fd = open_e2fs(dev, O_RDWR);
+ memset(sb.s_volume_name, 0, VOLNAMSZ);
+ strncpy(sb.s_volume_name, label, VOLNAMSZ);
+ if (strlen(label) > VOLNAMSZ)
+ fprintf(stderr, _("Warning: label too long, truncating.\n"));
+ if (lseek(fd, 1024, SEEK_SET) != 1024) {
+ perror(dev);
+ fprintf (stderr, _("e2label: cannot seek to superblock again\n"));
+ exit(1);
+ }
+ if (write(fd, (char *) &sb, sizeof(sb)) != sizeof(sb)) {
+ perror(dev);
+ fprintf (stderr, _("e2label: error writing superblock\n"));
+ exit(1);
+ }
+}
+
+int main (int argc, char ** argv)
+{
+ if (argc == 2)
+ print_label(argv[1]);
+ else if (argc == 3)
+ change_label(argv[1], argv[2]);
+ else {
+ fprintf(stderr, _("Usage: e2label device [newlabel]\n"));
+ exit(1);
+ }
+ return 0;
+}