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2026-04-14 07:46:28 +02:00 · 1997-07-09 15:32:31 +00:00
parent a9309ad872
commit 8d71f2bb2d
1 changed files with 111 additions and 0 deletions
--- a/lib/strverscmp.c
+++ b/lib/strverscmp.c
@@ -0,0 +1,111 @@
+/* Compare strings while treating digits characters numerically.
+   Copyright (C) 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jean-Francois 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <string.h>
+#include <ctype.h>
+
+/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
+           Fractionnal parts, S_Z: idem but with leading Zeroes only */
+#define S_N    0x0
+#define S_I    0x4
+#define S_F    0x8
+#define S_Z    0xC
+
+/* 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 (s1, s2)
+     const char *s1;
+     const char *s2;
+{
+  const unsigned char *p1 = (const unsigned char *) s1;
+  const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+  int state;
+  int diff;
+
+  /* Symbol(s)    0       [1-9]   others  (padding)
+     Transition   (10) 0  (01) d  (00) x  (11) -   */
+  static const unsigned int next_state[] =
+  {
+      /* state    x    d    0    - */
+      /* S_N */  S_N, S_I, S_Z, S_N,
+      /* S_I */  S_N, S_I, S_I, S_I,
+      /* S_F */  S_N, S_F, S_F, S_F,
+      /* S_Z */  S_N, S_F, S_Z, S_Z
+  };
+
+  static const int result_type[] =
+  {
+      /* state   x/x  x/d  x/0  x/-  d/x  d/d  d/0  d/-
+                 0/x  0/d  0/0  0/-  -/x  -/d  -/0  -/- */
+
+      /* S_N */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_I */  CMP, -1,  -1,  CMP, +1,  LEN, LEN, CMP,
+                 +1,  LEN, LEN, CMP, CMP, CMP, CMP, CMP,
+      /* S_F */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
+                 CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
+      /* S_Z */  CMP, +1,  +1,  CMP, -1,  CMP, CMP, CMP,
+                 -1,  CMP, CMP, CMP
+  };
+
+  if (p1 == p2)
+    return 0;
+
+  c1 = *p1++;
+  c2 = *p2++;
+  /* Hint: '0' is a digit too.  */
+  state = S_N | (c1 == '0') + (isdigit (c1) != 0);
+
+  while ((diff = c1 - c2) == 0 && c1 != '\0')
+    {
+      state = next_state[state];
+      c1 = *p1++;
+      c2 = *p2++;
+      state |= (c1 == '0') + (isdigit (c1) != 0);
+    }
+
+  state = result_type[state << 2 | ((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;
+  }
+}