fdisk: remove goto; inline valid(); merge xprintf() calls; shrink sys_types

sys_types had used char[_PATH_MAX] for 22-char max strings.
When this is done 48 times, it nearly doubles the size of toybox.

goto should only be used when it is the easiest way to bail out.
That does not mean "when we need to fall back to returning a one-liner
that asks user input", nor is it suitable for looping:
C has while () and do { } while (); for a reason.

valid was called once. As such, it belonged inline.

print_*menu could probably be inlined, but I did not do this yet
in case a table-driven approach works better.
This uses C string concatenation to break an overly long message up,
while not wasting function calls.

1 files changed, 51 insertions, 55 deletions

diff --git a/toys/pending/fdisk.c b/toys/pending/fdisk.c
index 1432ee34..24769c68 100644
--- a/toys/pending/fdisk.c
+++ b/toys/pending/fdisk.c
@@ -62,7 +62,7 @@ struct part_entry {
 
 struct part_types {
   int id;
-  char type[PATH_MAX];
+  char type[24];
 } sys_types[] = {
   {0x00, "Empty"}, {0x01, "FAT12"}, {0x04, "FAT16 <32M"}, {0x05, "Extended"},
   {0x06, "FAT16"}, {0x07, "HPFS/NTFS"}, {0x0a, "OS/2 Boot Manager"},
@@ -145,20 +145,18 @@ static void list_types(void)
   xputc('\n');
 }
 
-static int valid(long size)
-{
-  if (size == 512 || size == 1024 || size == 2048 || size == 4096) return 1;
-  else {
-      toys.exithelp = 1;
-      error_exit("");
-  }
-}
-
 static void read_sec_sz()
 {
   int arg;       
   if (ioctl(dev_fd, BLKSSZGET, &arg) == 0) g_sect_size = arg;
-  if ((toys.optflags & FLAG_b) && valid(TT.sect_sz)) g_sect_size = TT.sect_sz;
+  if (toys.optflags & FLAG_b) {
+    if (TT.sect_sz !=  512 && TT.sect_sz != 1024 && TT.sect_sz != 2048 &&
+        TT.sect_sz != 4096) {
+      toys.exithelp++;
+      error_exit("bad sector size");
+    }
+    g_sect_size = TT.sect_sz;
+  }
 }
 
 static sector_t read_size()
@@ -528,13 +526,13 @@ static int read_input(char *mesg, char *outp)
 {
   char *p;
   int size = 0;
-redo:
-  xprintf("%s", mesg);
-  p = fgets(toybuf, 80, stdin);
+  do {
+    xprintf("%s", mesg);
+    p = fgets(toybuf, 80, stdin);
   
-  if (!p || !(size = strlen(p))) exit(0);
-  if (p[size-1] == '\n') p[--size] = '\0';
-  if (!size) goto redo;
+    if (!p || !(size = strlen(p))) exit(0);
+    if (p[size-1] == '\n') p[--size] = '\0';
+  } while (!size);
 
   while (*p != '\0' && *p <= ' ') p++;
   if (outp) memcpy(outp, p, strlen(p) + 1); //1 for nul
@@ -687,15 +685,14 @@ static int get_non_free_partition(int max)
 
   for (i = 0; i < max; i++) {
     if (!is_partition_clear(partitions[i].part)) {
-      if (num >= 0) goto get_from_user;
+      if (num >= 0)
+        return ask_partition(num_parts)-1;
       num = i;
     }
   }
   (num >= 0) ? xprintf("Selected partition %d\n",num+1):
     xprintf("No partition is defined yet!\n");
   return num;
-get_from_user:
-  return ask_partition(num_parts)-1;
 }
 
 /* a try at autodetecting an empty partition table entry,
@@ -707,15 +704,14 @@ static int get_free_partition(int max)
 
   for (i = 0; i < max; i++) {
     if (is_partition_clear(partitions[i].part)) {
-      if (num >= 0) goto get_from_user;
+      if (num >= 0)
+        return ask_partition(4)-1;
       num = i;
     }
   }
   (num >= 0) ? xprintf("Selected partition %d\n",num+1):
     xprintf("All primary partitions have been defined already!\n");
   return num;
-get_from_user:
-  return ask_partition(4)-1;
 }
 
 //taking user input for partition start/end sectors/cyinders
@@ -831,12 +827,12 @@ static sector_t ask_start_sector(int idx, sector_t* begin, sector_t* end, int ex
     if (asked) valid = validate(start_index, begin, end, start, asked);
     if (valid) break;
 
-find_start_again:
-    for (i = start_index; i < num_parts; i++) 
-      if (start >= begin[i] && start <= end[i])
-        start = end[i] + 1 + ((idx >= 4)? offset : 0);
+    do {
+      for (i = start_index; i < num_parts; i++) 
+        if (start >= begin[i] && start <= end[i])
+          start = end[i] + 1 + ((idx >= 4)? offset : 0);
+    } while (!validate(start_index, begin, end, start, 0));
 
-    if (!validate(start_index, begin, end, start, 0)) goto find_start_again;
     start_cyl = start/(g_sectors * g_heads) + 1;
     limit_cyl = limit/(g_sectors * g_heads) + 1;
 
@@ -1282,37 +1278,37 @@ static void fix_order(void)
 
 static void print_menu(void)
 {
-  xprintf("a\ttoggle a bootable flag\n");
-  xprintf("b\tedit bsd disklabel\n");
-  xprintf("c\ttoggle the dos compatibility flag\n");
-  xprintf("d\tdelete a partition\n");
-  xprintf("l\tlist known partition types\n");
-  xprintf("n\tadd a new partition\n");
-  xprintf("o\tcreate a new empty DOS partition table\n");
-  xprintf("p\tprint the partition table\n");
-  xprintf("q\tquit without saving changes\n");
-  xprintf("s\tcreate a new empty Sun disklabel\n");  /* sun */
-  xprintf("t\tchange a partition's system id\n");
-  xprintf("u\tchange display/entry units\n");
-  xprintf("v\tverify the partition table\n");
-  xprintf("w\twrite table to disk and exit\n");
-  xprintf("x\textra functionality (experts only)\n");
+  xprintf("a\ttoggle a bootable flag\n"
+  "b\tedit bsd disklabel\n"
+  "c\ttoggle the dos compatibility flag\n"
+  "d\tdelete a partition\n"
+  "l\tlist known partition types\n"
+  "n\tadd a new partition\n"
+  "o\tcreate a new empty DOS partition table\n"
+  "p\tprint the partition table\n"
+  "q\tquit without saving changes\n"
+  "s\tcreate a new empty Sun disklabel\n"
+  "t\tchange a partition's system id\n"
+  "u\tchange display/entry units\n"
+  "v\tverify the partition table\n"
+  "w\twrite table to disk and exit\n"
+  "x\textra functionality (experts only)\n");
 }
 
 static void print_xmenu(void)
 {
-  xprintf("b\tmove beginning of data in a partition\n");
-  xprintf("c\tchange number of cylinders\n");
-  xprintf("d\tprint the raw data in the partition table\n");
-  xprintf("e\tlist extended partitions\n");
-  xprintf("f\tfix partition order\n");    
-  xprintf("h\tchange number of heads\n");
-  xprintf("p\tprint the partition table\n");
-  xprintf("q\tquit without saving changes\n");
-  xprintf("r\treturn to main menu\n");
-  xprintf("s\tchange number of sectors/track\n");
-  xprintf("v\tverify the partition table\n");
-  xprintf("w\twrite table to disk and exit\n");
+  xprintf("b\tmove beginning of data in a partition\n"
+  "c\tchange number of cylinders\n"
+  "d\tprint the raw data in the partition table\n"
+  "e\tlist extended partitions\n"
+  "f\tfix partition order\n"  
+  "h\tchange number of heads\n"
+  "p\tprint the partition table\n"
+  "q\tquit without saving changes\n"
+  "r\treturn to main menu\n"
+  "s\tchange number of sectors/track\n"
+  "v\tverify the partition table\n"
+  "w\twrite table to disk and exit\n");
 }
 
 static void expert_menu(void)