add a -s option to swapon

Signed-off-by: John Crispin <blogic@openwrt.org>

diff --git a/block.c b/block.c
index 860a95cead30e087d2241794e15611d658b07806..409365847998cdd084db1ad40dd4d60fb812135a 100644 (file)
--- a/block.c
+++ b/block.c
@@ -12,6 +12,7 @@
  * GNU General Public License for more details.
  */
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <unistd.h>
 #include <syslog.h>
@@ -877,11 +878,25 @@ static int main_info(int argc, char **argv)
 static int main_swapon(int argc, char **argv)
 {
        if (argc != 2) {
-               fprintf(stderr, "Usage: swapoff [-a] [DEVICE]\n\nStop swapping on DEVICE\n\n\t-a      Stop swapping on all swap devices\n");
+               fprintf(stderr, "Usage: swapon <-s> <-a> [DEVICE]\n\n\tStart swapping on [DEVICE]\n -a\tStart swapping on all swap devices\n -s\tShow summary\n");
                return -1;
        }
 
-       if (!strcmp(argv[1], "-a")) {
+       if (!strcmp(argv[1], "-s")) {
+               FILE *fp = fopen("/proc/swaps", "r");
+               char *lineptr = NULL;
+               size_t s;
+
+               if (!fp) {
+                       fprintf(stderr, "failed to open /proc/swaps\n");
+                       return -1;
+               }
+               while (getline(&lineptr, &s, fp) > 0)
+                       printf(lineptr);
+               if (lineptr)
+                       free(lineptr);
+               fclose(fp);
+       } else if (!strcmp(argv[1], "-a")) {
                struct blkid_struct_probe *pr;
 
                cache_load(0);