1 files changed, 112 insertions, 0 deletions
diff --git a/lib/gl/strverscmp.c b/lib/gl/strverscmp.c
new file mode 100644
index 0000000..83922ea
--- /dev/null
+++ b/lib/gl/strverscmp.c
@@ -0,0 +1,112 @@
+/* Compare strings while treating digits characters numerically.
+   Copyright (C) 1997-2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _LIBC
+# include <libc-config.h>
+# define __strverscmp strverscmp
+#endif
+
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+
+/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
+           fractional parts, S_Z: idem but with leading Zeroes only */
+#define  S_N    0x0
+#define  S_I    0x3
+#define  S_F    0x6
+#define  S_Z    0x9
+
+/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
+#define  CMP    2
+#define  LEN    3
+
+
+/* Compare S1 and S2 as strings holding indices/version numbers,
+   returning less than, equal to or greater than zero if S1 is less than,
+   equal to or greater than S2 (for more info, see the texinfo doc).
+*/
+
+int
+__strverscmp (const char *s1, const char *s2)
+{
+  const unsigned char *p1 = (const unsigned char *) s1;
+  const unsigned char *p2 = (const unsigned char *) s2;
+
+  /* Symbol(s)    0       [1-9]   others
+     Transition   (10) 0  (01) d  (00) x   */
+  static const uint_least8_t next_state[] =
+  {
+      /* state    x    d    0  */
+      /* S_N */  S_N, S_I, S_Z,
+      /* S_I */  S_N, S_I, S_I,
+      /* S_F */  S_N, S_F, S_F,
+      /* S_Z */  S_N, S_F, S_Z
+  };
+
+  static const int_least8_t result_type[] =
+  {
+      /* state   x/x  x/d  x/0  d/x  d/d  d/0  0/x  0/d  0/0  */
+
+      /* S_N */  CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
+      /* S_I */  CMP, -1,  -1,  +1,  LEN, LEN, +1,  LEN, LEN,
+      /* S_F */  CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_Z */  CMP, +1,  +1,  -1,  CMP, CMP, -1,  CMP, CMP
+  };
+
+  if (p1 == p2)
+    return 0;
+
+  unsigned char c1 = *p1++;
+  unsigned char c2 = *p2++;
+  /* Hint: '0' is a digit too.  */
+  int state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
+
+  int diff;
+  while ((diff = c1 - c2) == 0)
+    {
+      if (c1 == '\0')
+	return diff;
+
+      state = next_state[state];
+      c1 = *p1++;
+      c2 = *p2++;
+      state += (c1 == '0') + (isdigit (c1) != 0);
+    }
+
+  state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
+
+  switch (state)
+  {
+    case CMP:
+      return diff;
+
+    case LEN:
+      while (isdigit (*p1++))
+	if (!isdigit (*p2++))
+	  return 1;
+
+      return isdigit (*p2) ? -1 : diff;
+
+    default:
+      return state;
+  }
+}
+libc_hidden_def (__strverscmp)
+weak_alias (__strverscmp, strverscmp)