Re-organized some sections and added a whole new section on avoiding the

[oweals/busybox.git] / update.c

diff --git a/update.c b/update.c
index 14f1d3c2081dcfaa3268b167a55f72fe821665f3..7279d83a87981c3d47ddd370c76b597d41080600 100644 (file)
--- a/update.c
+++ b/update.c
@@ -23,27 +23,22 @@
  *
  */
 
-#include "internal.h"
-#include <linux/unistd.h>
+/*
+ * Note: This program is only necessary if you are running a 2.0.x (or
+ * earlier) kernel. 2.2.x and higher flush filesystem buffers automatically.
+ */
+
+#include "busybox.h"
 #include <sys/param.h>
 #include <sys/syslog.h>
+#include <unistd.h> /* for getopt() */
+
 
 #if defined(__GLIBC__)
 #include <sys/kdaemon.h>
 #else
-_syscall2(int, bdflush, int, func, int, data);
-#endif                                                 /* __GLIBC__ */
-
-static char update_usage[] =
-       "update [options]\n"
-#ifndef BB_FEATURE_TRIVIAL_HELP
-       "\nPeriodically flushes filesystem buffers.\n\n"
-       "Options:\n"
-       "\t-S\tforce use of sync(2) instead of flushing\n"
-       "\t-s SECS\tcall sync this often (default 30)\n"
-       "\t-f SECS\tflush some buffers this often (default 5)\n"
-#endif
-       ;
+static _syscall2(int, bdflush, int, func, int, data);
+#endif /* __GLIBC__ */
 
 static unsigned int sync_duration = 30;
 static unsigned int flush_duration = 5;
@@ -52,29 +47,22 @@ static int use_sync = 0;
 extern int update_main(int argc, char **argv)
 {
        int pid;
+       int opt;
 
-       argc--;
-       argv++;
-       while (argc>0 && **argv == '-') {
-               while (*++(*argv)) {
-                       switch (**argv) {
+       while ((opt = getopt(argc, argv, "Ss:f:")) > 0) {
+               switch (opt) {
                        case 'S':
                                use_sync = 1;
                                break;
                        case 's':
-                               if (--argc < 1) usage(update_usage);
-                               sync_duration = atoi(*(++argv));
+                               sync_duration = atoi(optarg);
                                break;
                        case 'f':
-                               if (--argc < 1) usage(update_usage);
-                               flush_duration = atoi(*(++argv));
+                               flush_duration = atoi(optarg);
                                break;
                        default:
                                usage(update_usage);
-                       }
                }
-               argc--;
-               argv++;
        }
 
        pid = fork();
@@ -84,12 +72,19 @@ extern int update_main(int argc, char **argv)
                /* Become a proper daemon */
                setsid();
                chdir("/");
+#ifdef OPEN_MAX
                for (pid = 0; pid < OPEN_MAX; pid++) close(pid);
+#else
+               /* glibc 2.1.92 requires using sysconf(_SC_OPEN_MAX) */
+               for (pid = 0; pid < sysconf(_SC_OPEN_MAX); pid++) close(pid);
+#endif
 
                /*
                 * This is no longer necessary since 1.3.5x, but it will harmlessly
                 * exit if that is the case.
                 */
+
+               /* set the program name that will show up in a 'ps' listing */
                argv[0] = "bdflush (update)";
                argv[1] = NULL;
                argv[2] = NULL;
@@ -109,7 +104,7 @@ extern int update_main(int argc, char **argv)
                        }
                }
        }
-       exit( TRUE);
+       return( TRUE);
 }
 
 /*