114 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			114 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
| /* Compare strings while treating digits characters numerically.
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|    Copyright (C) 1997 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, write to the Free
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|    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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|    02111-1307 USA.  */
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| 
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| #include <string.h>
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| #include <ctype.h>
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| #include <machine/weakalias.h>
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| 
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| /* states: S_N: normal, S_I: comparing integral part, S_F: comparing
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|            fractionnal parts, S_Z: idem but with leading Zeroes only */
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| #define  S_N    0x0
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| #define  S_I    0x4
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| #define  S_F    0x8
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| #define  S_Z    0xC
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| 
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| /* result_type: CMP: return diff; LEN: compare using len_diff/diff */
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| #define  CMP    2
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| #define  LEN    3
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| 
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| 
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| /* Compare S1 and S2 as strings holding indices/version numbers,
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|    returning less than, equal to or greater than zero if S1 is less than,
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|    equal to or greater than S2 (for more info, see the texinfo doc).
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| */
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| 
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| int
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| __strverscmp (s1, s2)
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|      const char *s1;
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|      const char *s2;
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| {
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|   const unsigned char *p1 = (const unsigned char *) s1;
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|   const unsigned char *p2 = (const unsigned char *) s2;
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|   unsigned char c1, c2;
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|   int state;
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|   int diff;
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| 
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|   /* Symbol(s)    0       [1-9]   others  (padding)
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|      Transition   (10) 0  (01) d  (00) x  (11) -   */
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|   static const unsigned int next_state[] =
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|   {
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|       /* state    x    d    0    - */
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|       /* S_N */  S_N, S_I, S_Z, S_N,
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|       /* S_I */  S_N, S_I, S_I, S_I,
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|       /* S_F */  S_N, S_F, S_F, S_F,
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|       /* S_Z */  S_N, S_F, S_Z, S_Z
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|   };
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| 
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|   static const int result_type[] =
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|   {
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|       /* state   x/x  x/d  x/0  x/-  d/x  d/d  d/0  d/-
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|                  0/x  0/d  0/0  0/-  -/x  -/d  -/0  -/- */
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| 
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|       /* S_N */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
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|                  CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
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|       /* S_I */  CMP, -1,  -1,  CMP, +1,  LEN, LEN, CMP,
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|                  +1,  LEN, LEN, CMP, CMP, CMP, CMP, CMP,
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|       /* S_F */  CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP,
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|                  CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
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|       /* S_Z */  CMP, +1,  +1,  CMP, -1,  CMP, CMP, CMP,
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|                  -1,  CMP, CMP, CMP
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|   };
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| 
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|   if (p1 == p2)
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|     return 0;
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| 
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|   c1 = *p1++;
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|   c2 = *p2++;
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|   /* Hint: '0' is a digit too.  */
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|   state = S_N | ((c1 == '0') + (isdigit (c1) != 0));
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| 
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|   while ((diff = c1 - c2) == 0 && c1 != '\0')
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|     {
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|       state = next_state[state];
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|       c1 = *p1++;
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|       c2 = *p2++;
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|       state |= (c1 == '0') + (isdigit (c1) != 0);
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|     }
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| 
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|   state = result_type[state << 2 | (((c2 == '0') + (isdigit (c2) != 0)))];
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| 
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|   switch (state)
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|   {
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|     case CMP:
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|       return diff;
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| 
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|     case LEN:
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|       while (isdigit (*p1++))
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| 	if (!isdigit (*p2++))
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| 	  return 1;
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| 
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|       return isdigit (*p2) ? -1 : diff;
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| 
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|     default:
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|       return state;
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|   }
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| }
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| weak_alias (__strverscmp, strverscmp)
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