sort: add -V "sort version"

function                                             old     new   delta
packed_usage                                       32855   32858      +3
get_key                                              500     503      +3
sort_opt_str                                          36      37      +1
sort_main                                           1037    1036      -1
compare_keys                                         795     783     -12
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/2 up/down: 7/-13)              Total: -6 bytes

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

1 files changed, 27 insertions, 20 deletions

diff --git a/coreutils/sort.c b/coreutils/sort.c
index 4d741e76d..05e5c9071 100644
--- a/coreutils/sort.c
+++ b/coreutils/sort.c
@@ -60,6 +60,7 @@
 //usage:        IF_FEATURE_SORT_BIG(
 //usage:     "\n        -g      General numerical sort"
 //usage:     "\n        -M      Sort month"
+//usage:     "\n        -V      Sort version"
 //usage:     "\n        -t CHAR Field separator"
 //usage:     "\n        -k N[,M] Sort by Nth field"
 //usage:        )
@@ -91,32 +92,33 @@
 
 /* These are sort types */
 enum {
-        FLAG_n  = 1,            /* Numeric sort */
-        FLAG_g  = 2,            /* Sort using strtod() */
-        FLAG_M  = 4,            /* Sort date */
+        FLAG_n  = 1 << 0,       /* Numeric sort */
+        FLAG_g  = 1 << 1,       /* Sort using strtod() */
+        FLAG_M  = 1 << 2,       /* Sort date */
+        FLAG_V  = 1 << 3,       /* Sort version */
 /* ucsz apply to root level only, not keys.  b at root level implies bb */
-        FLAG_u  = 8,            /* Unique */
-        FLAG_c  = 0x10,         /* Check: no output, exit(!ordered) */
-        FLAG_s  = 0x20,         /* Stable sort, no ascii fallback at end */
-        FLAG_z  = 0x40,         /* Input and output is NUL terminated, not \n */
+        FLAG_u  = 1 << 4,       /* Unique */
+        FLAG_c  = 1 << 5,       /* Check: no output, exit(!ordered) */
+        FLAG_s  = 1 << 6,       /* Stable sort, no ascii fallback at end */
+        FLAG_z  = 1 << 7,       /* Input and output is NUL terminated, not \n */
 /* These can be applied to search keys, the previous four can't */
-        FLAG_b  = 0x80,         /* Ignore leading blanks */
-        FLAG_r  = 0x100,        /* Reverse */
-        FLAG_d  = 0x200,        /* Ignore !(isalnum()|isspace()) */
-        FLAG_f  = 0x400,        /* Force uppercase */
-        FLAG_i  = 0x800,        /* Ignore !isprint() */
-        FLAG_m  = 0x1000,       /* ignored: merge already sorted files; do not sort */
-        FLAG_S  = 0x2000,       /* ignored: -S, --buffer-size=SIZE */
-        FLAG_T  = 0x4000,       /* ignored: -T, --temporary-directory=DIR */
-        FLAG_o  = 0x8000,
-        FLAG_k  = 0x10000,
-        FLAG_t  = 0x20000,
+        FLAG_b  = 1 << 8,       /* Ignore leading blanks */
+        FLAG_r  = 1 << 9,       /* Reverse */
+        FLAG_d  = 1 << 10,      /* Ignore !(isalnum()|isspace()) */
+        FLAG_f  = 1 << 11,      /* Force uppercase */
+        FLAG_i  = 1 << 12,      /* Ignore !isprint() */
+        FLAG_m  = 1 << 13,      /* ignored: merge already sorted files; do not sort */
+        FLAG_S  = 1 << 14,      /* ignored: -S, --buffer-size=SIZE */
+        FLAG_T  = 1 << 15,      /* ignored: -T, --temporary-directory=DIR */
+        FLAG_o  = 1 << 16,
+        FLAG_k  = 1 << 17,
+        FLAG_t  = 1 << 18,
         FLAG_bb = 0x80000000,   /* Ignore trailing blanks  */
         FLAG_no_tie_break = 0x40000000,
 };
 
 static const char sort_opt_str[] ALIGN1 = "^"
-                        "ngMucszbrdfimS:T:o:k:*t:"
+                        "ngMVucszbrdfimS:T:o:k:*t:"
                         "\0" "o--o:t--t"/*-t, -o: at most one of each*/;
 /*
  * OPT_STR must not be string literal, needs to have stable address:
@@ -273,10 +275,15 @@ static int compare_keys(const void *xarg, const void *yarg)
                 y = *(char **)yarg;
 #endif
                 /* Perform actual comparison */
-                switch (flags & (FLAG_n | FLAG_M | FLAG_g)) {
+                switch (flags & (FLAG_n | FLAG_g | FLAG_M | FLAG_V)) {
                 default:
                         bb_error_msg_and_die("unknown sort type");
                         break;
+#if defined(HAVE_STRVERSCMP) && HAVE_STRVERSCMP == 1
+                case FLAG_V:
+                        retval = strverscmp(x, y);
+                        break;
+#endif
                 /* Ascii sort */
                 case 0:
 #if ENABLE_LOCALE_SUPPORT