create a document for mdev so people dont have to rtfs

[oweals/busybox.git] / util-linux / swaponoff.c

diff --git a/util-linux/swaponoff.c b/util-linux/swaponoff.c
index 5a2d735ad8f65fca130ee51a131829393799aa9a..e1de4eb0ce9cbd8689ed0df3cfdc7d6b685bfd26 100644 (file)
--- a/util-linux/swaponoff.c
+++ b/util-linux/swaponoff.c
@@ -1,121 +1,78 @@
+/* vi: set sw=4 ts=4: */
 /*
  * Mini swapon/swapoff implementation for busybox
  *
- * Copyright (C) 1998 by Erik Andersen <andersee@debian.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
+ * Licensed under the GPL version 2, see the file LICENSE in this tarball.
  */
 
-#include "internal.h"
-#include <stdio.h>
-#include <sys/mount.h>
-#include <sys/swap.h>
+#include "busybox.h"
 #include <mntent.h>
-#include <dirent.h>
-#include <fstab.h>
-#include <errno.h>
+#include <sys/swap.h>
 
 
-static int whichApp;
-static const char* appName;
+static int swap_enable_disable(char *device)
+{
+       int status;
+       struct stat st;
 
-static const char swapoff_usage[] = 
-"swapoff device\n"
-"\nStop swapping virtual memory pages on the given device.\n";
-static const char swapon_usage[] = 
-"swapon device\n"
-"\nStart swapping virtual memory pages on the given device.\n";
+       xstat(device, &st);
 
+       /* test for holes */
+       if (S_ISREG(st.st_mode))
+               if (st.st_blocks * 512 < st.st_size)
+                       bb_error_msg_and_die("swap file has holes");
 
-#define SWAPON_APP   1
-#define SWAPOFF_APP  2
+       if (applet_name[5] == 'n')
+               status = swapon(device, 0);
+       else
+               status = swapoff(device);
 
+       if (status != 0) {
+               bb_perror_msg("%s", device);
+               return 1;
+       }
 
-static void
-swap_enable_disable( char *device)
-{
-    int status;
-    if ( whichApp == SWAPON_APP )
-       status = swapon(device, 0);
-    else 
-       status = swapoff(device);
-
-    if ( status != 0 ) { 
-       perror(appName);
-       exit( FALSE);
-    }
+       return 0;
 }
 
-static void
-do_em_all()
+static int do_em_all(void)
 {
        struct mntent *m;
-       char swapName[NAME_MAX];
-       FILE *f = setmntent ("/etc/fstab", "r");
+       FILE *f;
+       int err;
 
-       if (f == NULL) {
-           perror("/etc/fstab");
-           exit( FALSE); 
-       }
-       while ((m = getmntent (f)) != NULL) {
-           if (!strstr (m->mnt_type, "swap")) {
-                   swap_enable_disable( swapName);
-           }
-       }
-       endmntent (f);
-       exit( TRUE);
+       f = setmntent("/etc/fstab", "r");
+       if (f == NULL)
+               bb_perror_msg_and_die("/etc/fstab");
+
+       err = 0;
+       while ((m = getmntent(f)) != NULL)
+               if (strcmp(m->mnt_type, MNTTYPE_SWAP) == 0)
+                       err += swap_enable_disable(m->mnt_fsname);
+
+       endmntent(f);
+
+       return err;
 }
 
+#define DO_ALL    0x01
 
-extern int
-swap_on_off_main(int argc, char * * argv)
+int swap_on_off_main(int argc, char **argv);
+int swap_on_off_main(int argc, char **argv)
 {
-    struct stat statBuf;
-    if (stat("/etc/fstab", &statBuf) < 0) 
-       fprintf(stderr, "/etc/fstab file missing -- Please install one.\n\n");
-
-    if (strcmp(*argv, "swapon")==0) {
-       appName = *argv;
-       whichApp = SWAPON_APP;
-
-    } else {
-       appName = *argv;
-       whichApp = SWAPOFF_APP;
-    }
-
-    if (argc < 2)
-       goto usage_and_exit;
-    argc--;
-    argv++;
-
-    /* Parse any options */
-    while (**argv == '-') {
-       while (*++(*argv)) switch (**argv) {
-           case 'a':
-               do_em_all();
-               break;
-           default:
-               goto usage_and_exit;
-       }
-    }
-    swap_enable_disable(*argv);
-    exit( TRUE);
+       int ret;
 
-usage_and_exit:
-    usage( (whichApp==SWAPON_APP)? swapon_usage : swapoff_usage);
-    exit( FALSE);
-}
+       if (argc == 1)
+               bb_show_usage();
 
+       ret = getopt32(argc, argv, "a");
+       if (ret & DO_ALL)
+               return do_em_all();
+
+       ret = 0;
+       while (*++argv)
+               ret += swap_enable_disable(*argv);
+       return ret;
+}