fsck: more clever (->smaller) handling of parameters

function                                             old     new   delta
fsck_device                                          213     449    +236
new_args                                               -      46     +46
fsck_main                                           1870    1815     -55
execute                                              289       -    -289
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 1/1 up/down: 282/-344)          Total: -62 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 25 insertions, 26 deletions

diff --git a/e2fsprogs/fsck.c b/e2fsprogs/fsck.c
index c4d0b03ef..21b2fdc0d 100644
--- a/e2fsprogs/fsck.c
+++ b/e2fsprogs/fsck.c
@@ -490,60 +490,55 @@ static int wait_many(int flags)
 static void execute(const char *type, const char *device,
                 const char *mntpt /*, int interactive */)
 {
-        char *argv[num_args + 4]; /* see count below: */
-        int argc;
         int i;
         struct fsck_instance *inst;
         pid_t pid;
 
-        argv[0] = xasprintf("fsck.%s", type); /* 1 */
-        for (i = 0; i < num_args; i++)
-                argv[i+1] = args[i]; /* num_args */
-        argc = num_args + 1;
+        args[0] = xasprintf("fsck.%s", type);
 
 #if DO_PROGRESS_INDICATOR
         if (progress && !progress_active()) {
                 if (strcmp(type, "ext2") == 0
                  || strcmp(type, "ext3") == 0
                 ) {
-                        argv[argc++] = xasprintf("-C%d", progress_fd); /* 1 */
+                        args[XXX] = xasprintf("-C%d", progress_fd); /* 1 */
                         inst->flags |= FLAG_PROGRESS;
                 }
         }
 #endif
 
-        argv[argc++] = (char*)device; /* 1 */
-        argv[argc] = NULL; /* 1 */
+        args[num_args - 2] = (char*)device;
+        /* args[num_args - 1] = NULL; - already is */
 
         if (verbose || noexecute) {
-                printf("[%s (%d) -- %s]", argv[0], num_running,
+                printf("[%s (%d) -- %s]", args[0], num_running,
                                         mntpt ? mntpt : device);
-                for (i = 0; i < argc; i++)
-                        printf(" %s", argv[i]);
+                for (i = 0; args[i]; i++)
+                        printf(" %s", args[i]);
                 bb_putchar('\n');
         }
 
         /* Fork and execute the correct program. */
         pid = -1;
         if (!noexecute) {
-                pid = spawn(argv);
+                pid = spawn(args);
                 if (pid < 0)
-                        bb_simple_perror_msg(argv[0]);
+                        bb_simple_perror_msg(args[0]);
         }
 
 #if DO_PROGRESS_INDICATOR
-        free(argv[num_args + 1]);
+        free(args[XXX]);
 #endif
 
         /* No child, so don't record an instance */
         if (pid <= 0) {
-                free(argv[0]);
+                free(args[0]);
                 return;
         }
 
         inst = xzalloc(sizeof(*inst));
         inst->pid = pid;
-        inst->prog = argv[0];
+        inst->prog = args[0];
         inst->device = xstrdup(device);
         inst->base_device = base_device(device);
 #if DO_PROGRESS_INDICATOR
@@ -899,6 +894,12 @@ static void compile_fs_type(char *fs_type)
         }
 }
 
+static char **new_args(void)
+{
+        args = xrealloc_vector(args, 2, num_args);
+        return &args[num_args++];
+}
+
 int fsck_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int fsck_main(int argc UNUSED_PARAM, char **argv)
 {
@@ -922,11 +923,9 @@ int fsck_main(int argc UNUSED_PARAM, char **argv)
         opts_for_fsck = doall = notitle = 0;
         devices = NULL;
         num_devices = 0;
-        /* in bss, so already zeroed
-        args = NULL;
-        num_args = 0;
-        instance_list = NULL;
-        */
+        new_args(); /* args[0] = NULL, will be replaced by fsck.<type> */
+        /* instance_list = NULL; - in bss, so already zeroed */
+
         while (*++argv) {
                 int j;
                 int optpos;
@@ -944,8 +943,7 @@ int fsck_main(int argc UNUSED_PARAM, char **argv)
                 }
 
                 if (arg[0] != '-' || opts_for_fsck) {
-                        args = xrealloc_vector(args, 2, num_args);
-                        args[num_args++] = arg;
+                        *new_args() = arg;
                         continue;
                 }
 
@@ -1022,8 +1020,7 @@ int fsck_main(int argc UNUSED_PARAM, char **argv)
                 if (optpos) {
                         options[0] = '-';
                         options[optpos + 1] = '\0';
-                        args = xrealloc_vector(args, 2, num_args);
-                        args[num_args++] = options;
+                        *new_args() = options;
                 }
         }
         if (getenv("FSCK_FORCE_ALL_PARALLEL"))
@@ -1031,6 +1028,8 @@ int fsck_main(int argc UNUSED_PARAM, char **argv)
         tmp = getenv("FSCK_MAX_INST");
         if (tmp)
                 max_running = xatoi(tmp);
+        new_args(); /* args[num_args - 2] will be replaced by <device> */
+        new_args(); /* args[num_args - 1] is the last, NULL element */
 
         if (!notitle)
                 puts("fsck (busybox "BB_VER", "BB_BT")");