FS#8961 - Anti-Aliased Fonts.
[kugel-rb.git] / firmware / common / strcasestr.c
blob095eebdd66a844c12930de33eed2a8305fc5f661
1 /* Return the offset of one string within another.
2 Copyright (C) 1994,1996,1997,1998,1999,2000 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
21 * My personal strstr() implementation that beats most other algorithms.
22 * Until someone tells me otherwise, I assume that this is the
23 * fastest implementation of strstr() in C.
24 * I deliberately chose not to comment it. You should have at least
25 * as much fun trying to understand it, as I had to write it :-).
27 * Stephen R. van den Berg, berg@pool.informatik.rwth-aachen.de*/
29 /* Faster looping by precalculating bl, bu, cl, cu before looping.
30 * 2004 Apr 08 Jose Da Silva, digital@joescat@com */
32 #include <string.h>
33 #include <ctype.h>
35 typedef unsigned chartype;
37 char* strcasestr (const char* phaystack, const char* pneedle)
39 const unsigned char *haystack, *needle;
40 chartype bl, bu, cl, cu;
42 haystack = (const unsigned char *) phaystack;
43 needle = (const unsigned char *) pneedle;
45 bl = tolower (*needle);
46 if (bl != '\0')
48 bu = toupper (bl);
49 haystack--;/* possible ANSI violation */
52 cl = *++haystack;
53 if (cl == '\0')
54 goto ret0;
56 while ((cl != bl) && (cl != bu));
58 cl = tolower (*++needle);
59 if (cl == '\0')
60 goto foundneedle;
61 cu = toupper (cl);
62 ++needle;
63 goto jin;
65 for (;;)
67 chartype a;
68 const unsigned char *rhaystack, *rneedle;
72 a = *++haystack;
73 if (a == '\0')
74 goto ret0;
75 if ((a == bl) || (a == bu))
76 break;
77 a = *++haystack;
78 if (a == '\0')
79 goto ret0;
80 shloop:
83 while ((a != bl) && (a != bu));
85 jin: a = *++haystack;
86 if (a == '\0')
87 goto ret0;
89 if ((a != cl) && (a != cu))
90 goto shloop;
92 rhaystack = haystack-- + 1;
93 rneedle = needle;
94 a = tolower (*rneedle);
96 if (tolower (*rhaystack) == (int) a)
99 if (a == '\0')
100 goto foundneedle;
101 ++rhaystack;
102 a = tolower (*++needle);
103 if (tolower (*rhaystack) != (int) a)
104 break;
105 if (a == '\0')
106 goto foundneedle;
107 ++rhaystack;
108 a = tolower (*++needle);
110 while (tolower (*rhaystack) == (int) a);
112 needle = rneedle;/* took the register-poor approach */
114 if (a == '\0')
115 break;
118 foundneedle:
119 return (char*) haystack;
120 ret0:
121 return 0;