Add -L label and UUID support to mkswap.

1 files changed, 15 insertions, 3 deletions

diff --git a/toys/other/mkswap.c b/toys/other/mkswap.c
index ff864244..49e0b942 100644
--- a/toys/other/mkswap.c
+++ b/toys/other/mkswap.c
@@ -2,24 +2,30 @@
  *
  * Copyright 2009 Rob Landley <rob@landley.net>
 
-USE_MKSWAP(NEWTOY(mkswap, "<1>1", TOYFLAG_SBIN))
+USE_MKSWAP(NEWTOY(mkswap, "<1>1L:", TOYFLAG_SBIN))
 
 config MKSWAP
   bool "mkswap"
   default y
   help
-    usage: mkswap DEVICE
+    usage: mkswap [-L LABEL] DEVICE
 
     Sets up a Linux swap area on a device or file.
 */
 
+#define FOR_mkswap
 #include "toys.h"
 
+GLOBALS(
+  char *L;
+)
+
 void mkswap_main(void)
 {
   int fd = xopen(*toys.optargs, O_RDWR), pagesize = sysconf(_SC_PAGE_SIZE);
   off_t len = fdlength(fd);
   unsigned int pages = (len/pagesize)-1, *swap = (unsigned int *)toybuf;
+  char *label = (char *)(swap+7), *uuid = (char *)(swap+3);
 
   // Write header. Note that older kernel versions checked signature
   // on disk (not in cache) during swapon, so sync after writing.
@@ -27,6 +33,8 @@ void mkswap_main(void)
   swap[0] = 1;
   swap[1] = pages;
   xlseek(fd, 1024, SEEK_SET);
+  create_uuid(uuid);
+  if (TT.L) strncpy(label, TT.L, 15);
   xwrite(fd, swap, 129*sizeof(unsigned int));
   xlseek(fd, pagesize-10, SEEK_SET);
   xwrite(fd, "SWAPSPACE2", 10);
@@ -34,5 +42,9 @@ void mkswap_main(void)
 
   if (CFG_TOYBOX_FREE) close(fd);
 
-  printf("Swapspace size: %luk\n", pages*(unsigned long)(pagesize/1024));
+  if (TT.L) sprintf(toybuf, ", LABEL=%s", label);
+  else *toybuf = 0;
+  printf("Swapspace size: %luk%s, UUID=%s\n",
+    pages*(unsigned long)(pagesize/1024),
+    toybuf, show_uuid(uuid));
 }