getpot: add support for "a+" specifier for nonnegative int parameters.

By Vladimir Dronnikov <dronnikov at gmail.com>.
fdisk and top are converted as an example.

function                                             old     new   delta
getopt32                                            1340    1370     +30
top_main                                            1137    1120     -17
fdisk_main                                          3033    2949     -84
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 30/-101)           Total: -71 bytes

3 files changed, 55 insertions, 44 deletions

diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index 80d5d2822..46807a3b6 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -220,6 +220,14 @@ Special characters:
  "x--x" Variation of the above, it means that -x option should occur
         at most once.
 
+ "a+:"  A plus after a char in opt_complementary means that the parameter
+        for this option is a nonnegative integer. It will be processed
+        with xatoi_u() - allowed range is 0..INT_MAX.
+
+        int param;  // "unsigned param;" will also work
+        opt_complementary = "p+";
+        getopt32(argv, "p:", &param);
+
  "a::"  A double colon after a char in opt_complementary means that the
         option can occur multiple times. Each occurrence will be saved as
         a llist_t element instead of char*.
@@ -275,14 +283,20 @@ Special characters:
 
 const char *opt_complementary;
 
+enum {
+        PARAM_STRING,
+        PARAM_LIST,
+        PARAM_INT,
+};
+
 typedef struct {
-        int opt;
-        int list_flg;
+        unsigned char opt_char;
+        smallint param_type;
         unsigned switch_on;
         unsigned switch_off;
         unsigned incongruously;
         unsigned requires;
-        void **optarg;               /* char **optarg or llist_t **optarg */
+        void **optarg;  /* char**, llist_t** or int *. */
         int *counter;
 } t_complementary;
 
@@ -337,12 +351,14 @@ getopt32(char **argv, const char *applet_opts, ...)
         if (*s == '+' || *s == '-')
                 s++;
         while (*s) {
-                if (c >= 32) break;
-                on_off->opt = *s;
+                if (c >= 32)
+                        break;
+                on_off->opt_char = *s;
                 on_off->switch_on = (1 << c);
                 if (*++s == ':') {
                         on_off->optarg = va_arg(p, void **);
-                        while (*++s == ':') /* skip */;
+                        while (*++s == ':')
+                                continue;
                 }
                 on_off++;
                 c++;
@@ -375,11 +391,12 @@ getopt32(char **argv, const char *applet_opts, ...)
                 for (l_o = long_options; l_o->name; l_o++) {
                         if (l_o->flag)
                                 continue;
-                        for (on_off = complementary; on_off->opt != 0; on_off++)
-                                if (on_off->opt == l_o->val)
+                        for (on_off = complementary; on_off->opt_char; on_off++)
+                                if (on_off->opt_char == l_o->val)
                                         goto next_long;
-                        if (c >= 32) break;
-                        on_off->opt = l_o->val;
+                        if (c >= 32)
+                                break;
+                        on_off->opt_char = l_o->val;
                         on_off->switch_on = (1 << c);
                         if (l_o->has_arg != no_argument)
                                 on_off->optarg = va_arg(p, void **);
@@ -422,11 +439,15 @@ getopt32(char **argv, const char *applet_opts, ...)
                         s++;
                         continue;
                 }
-                for (on_off = complementary; on_off->opt; on_off++)
-                        if (on_off->opt == *s)
+                for (on_off = complementary; on_off->opt_char; on_off++)
+                        if (on_off->opt_char == *s)
                                 break;
                 if (c == ':' && s[2] == ':') {
-                        on_off->list_flg++;
+                        on_off->param_type = PARAM_LIST;
+                        continue;
+                }
+                if (c == '+' && (s[2] == ':' || s[2] == '\0')) {
+                        on_off->param_type = PARAM_INT;
                         continue;
                 }
                 if (c == ':' || c == '\0') {
@@ -454,8 +475,8 @@ getopt32(char **argv, const char *applet_opts, ...)
                                 else
                                         pair_switch = &(pair->switch_off);
                         } else {
-                                for (on_off = complementary; on_off->opt; on_off++)
-                                        if (on_off->opt == *s) {
+                                for (on_off = complementary; on_off->opt_char; on_off++)
+                                        if (on_off->opt_char == *s) {
                                                 *pair_switch |= on_off->switch_on;
                                                 break;
                                         }
@@ -508,9 +529,9 @@ getopt32(char **argv, const char *applet_opts, ...)
 #endif
                 c &= 0xff; /* fight libc's sign extension */
  loop_arg_is_opt:
-                for (on_off = complementary; on_off->opt != c; on_off++) {
+                for (on_off = complementary; on_off->opt_char != c; on_off++) {
                         /* c==0 if long opt have non NULL flag */
-                        if (on_off->opt == 0 && c != 0)
+                        if (on_off->opt_char == '\0' && c != '\0')
                                 bb_show_usage();
                 }
                 if (flags & on_off->incongruously)
@@ -521,8 +542,10 @@ getopt32(char **argv, const char *applet_opts, ...)
                 flags ^= trigger;
                 if (on_off->counter)
                         (*(on_off->counter))++;
-                if (on_off->list_flg) {
+                if (on_off->param_type == PARAM_LIST) {
                         llist_add_to_end((llist_t **)(on_off->optarg), optarg);
+                } else if (on_off->param_type == PARAM_INT) {
+                        *(unsigned*)(on_off->optarg) = xatoi_u(optarg);
                 } else if (on_off->optarg) {
                         *(char **)(on_off->optarg) = optarg;
                 }
@@ -550,7 +573,7 @@ getopt32(char **argv, const char *applet_opts, ...)
                 free(argv[1]);
 #endif
         /* check depending requires for given options */
-        for (on_off = complementary; on_off->opt; on_off++) {
+        for (on_off = complementary; on_off->opt_char; on_off++) {
                 if (on_off->requires && (flags & on_off->switch_on) &&
                                         (flags & on_off->requires) == 0)
                         bb_show_usage();
diff --git a/procps/top.c b/procps/top.c
index 4df58f227..37b6a0cdb 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -740,7 +740,7 @@ int top_main(int argc, char **argv)
         int count, lines, col;
         unsigned interval;
         int iterations;
-        char *sinterval, *siterations;
+        char *sinterval;
         SKIP_FEATURE_TOPMEM(const) unsigned scan_mask = TOP_MASK;
 #if ENABLE_FEATURE_USE_TERMIOS
         struct termios new_settings;
@@ -757,15 +757,12 @@ int top_main(int argc, char **argv)
         iterations = 0; /* infinite */
 
         /* do normal option parsing */
-        opt_complementary = "-";
-        getopt32(argv, "d:n:b", &sinterval, &siterations);
+        opt_complementary = "-:n+";
+        getopt32(argv, "d:n:b", &sinterval, &iterations);
         if (option_mask32 & 0x1) {
                 /* Need to limit it to not overflow poll timeout */
                 interval = xatou16(sinterval); // -d
         }
-        if (option_mask32 & 0x2)
-                iterations = xatoi_u(siterations); // -n
-        //if (option_mask32 & 0x4) // -b
 
         /* change to /proc */
         xchdir("/proc");
diff --git a/util-linux/fdisk.c b/util-linux/fdisk.c
index cd053b876..c98a74fc0 100644
--- a/util-linux/fdisk.c
+++ b/util-linux/fdisk.c
@@ -2754,7 +2754,6 @@ unknown_command(int c)
 int fdisk_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int fdisk_main(int argc, char **argv)
 {
-        char *str_b, *str_C, *str_H, *str_S;
         unsigned opt;
         /*
          *  fdisk -v
@@ -2776,8 +2775,9 @@ int fdisk_main(int argc, char **argv)
 
         INIT_G();
 
+        opt_complementary = "b+:C+:H+:S+"; /* numeric params */
         opt = getopt32(argv, "b:C:H:lS:u" USE_FEATURE_FDISK_BLKSIZE("s"),
-                                &str_b, &str_C, &str_H, &str_S);
+                                &sector_size, &user_cylinders, &user_heads, &user_sectors);
         argc -= optind;
         argv += optind;
         if (opt & OPT_b) { // -b
@@ -2785,27 +2785,18 @@ int fdisk_main(int argc, char **argv)
                    so cannot be combined with multiple disks,
                    and the same goes for the C/H/S options.
                 */
-                sector_size = xatoi_u(str_b);
-                if (sector_size != 512 && sector_size != 1024 &&
-                        sector_size != 2048)
+                if (sector_size != 512 && sector_size != 1024
+                 && sector_size != 2048)
                         bb_show_usage();
                 sector_offset = 2;
                 user_set_sector_size = 1;
         }
-        if (opt & OPT_C) user_cylinders = xatoi_u(str_C); // -C
-        if (opt & OPT_H) { // -H
-                user_heads = xatoi_u(str_H);
-                if (user_heads <= 0 || user_heads >= 256)
-                        user_heads = 0;
-        }
-        //if (opt & OPT_l) // -l
-        if (opt & OPT_S) { // -S
-                user_sectors = xatoi_u(str_S);
-                if (user_sectors <= 0 || user_sectors >= 64)
-                        user_sectors = 0;
-        }
-        if (opt & OPT_u) display_in_cyl_units = 0; // -u
-        //if (opt & OPT_s) // -s
+        if (user_heads <= 0 || user_heads >= 256)
+                user_heads = 0;
+        if (user_sectors <= 0 || user_sectors >= 64)
+                user_sectors = 0;
+        if (opt & OPT_u)
+                display_in_cyl_units = 0; // -u
 
         if (user_set_sector_size && argc != 1)
                 printf("Warning: the -b (set sector size) option should"