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-rw-r--r--libc/string/generic/strverscmp.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/libc/string/generic/strverscmp.c b/libc/string/generic/strverscmp.c
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+/* GNU's strverscmp() function, taken from glibc 2.3.2 sources
+ */
+
+/* Compare strings while treating digits characters numerically.
+ Copyright (C) 1997, 2002 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997.
+
+ Derived work for uClibc by Hai Zaar, Codefidence Ltd <haizaar@codefidence.com>
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <string.h>
+#include <ctype.h>
+#include <stdint.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 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
+
+/* using more efficient isdigit() */
+#undef isdigit
+#define isdigit(a) ((unsigned)((a) - '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,
+ 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;
+ 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 uint8_t 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 int8_t 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;
+ }
+}