X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fstrverscmp.c;h=830a5458b649961022126f774977e23c71540938;hb=b3024d9c5ab39fcce8d7aa8069c4d5bcd139a70b;hp=f8f5193ebac07e9221e940b451864ef09092b177;hpb=bf156c40d271f02bc0e6bde8686c33870b7898cc;p=gnulib.git

diff --git a/lib/strverscmp.c b/lib/strverscmp.c
index f8f5193eb..830a5458b 100644
--- a/lib/strverscmp.c
+++ b/lib/strverscmp.c
@@ -1,7 +1,7 @@
 /* Compare strings while treating digits characters numerically.
-   Copyright (C) 1997 Free Software Foundation, Inc.
+   Copyright (C) 1997, 2000 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
-   Contributed by Jean-Francois Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
+   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 Library General Public License as
@@ -18,6 +18,10 @@
    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA 02111-1307, USA.  */
 
+#if HAVE_CONFIG_H
+# include <config.h>
+#endif
+
 #include <string.h>
 #include <ctype.h>
 
@@ -32,6 +36,15 @@
 #define CMP    2
 #define LEN    3
 
+/* ISDIGIT differs from isdigit, as follows:
+   - Its arg may be any int or unsigned int; it need not be an unsigned char.
+   - It's guaranteed to evaluate its argument exactly once.
+   - It's typically faster.
+   Posix 1003.2-1992 section 2.5.2.1 page 50 lines 1556-1558 says that
+   only '0' through '9' are digits.  Prefer ISDIGIT to isdigit unless
+   it's important to use the locale's definition of `digit' even when the
+   host does not conform to Posix.  */
+#define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
 
 /* Compare S1 and S2 as strings holding indices/version numbers,
    returning less than, equal to or greater than zero if S1 is less than,
@@ -39,9 +52,7 @@
 */
 
 int
-strverscmp (s1, s2)
-     const char *s1;
-     const char *s2;
+strverscmp (const char *s1, const char *s2)
 {
   const unsigned char *p1 = (const unsigned char *) s1;
   const unsigned char *p2 = (const unsigned char *) s2;
@@ -67,11 +78,11 @@ strverscmp (s1, s2)
 
       /* 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_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,
+      /* S_Z */  CMP,  1,   1,  CMP, -1,  CMP, CMP, CMP,
                  -1,  CMP, CMP, CMP
   };
 
@@ -81,17 +92,17 @@ strverscmp (s1, s2)
   c1 = *p1++;
   c2 = *p2++;
   /* Hint: '0' is a digit too.  */
-  state = S_N | (c1 == '0') + (isdigit (c1) != 0);
+  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 |= (c1 == '0') + (ISDIGIT (c1) != 0);
     }
 
-  state = result_type[state << 2 | ((c2 == '0') + (isdigit (c2) != 0))];
+  state = result_type[state << 2 | ((c2 == '0') + (ISDIGIT (c2) != 0))];
 
   switch (state)
     {
@@ -99,11 +110,11 @@ strverscmp (s1, s2)
       return diff;
 
     case LEN:
-      while (isdigit (*p1++))
-	if (!isdigit (*p2++))
+      while (ISDIGIT (*p1++))
+	if (!ISDIGIT (*p2++))
 	  return 1;
 
-      return isdigit (*p2) ? -1 : diff;
+      return ISDIGIT (*p2) ? -1 : diff;
 
     default:
       return state;