xref: /plan9/sys/src/ape/lib/utf/utfutf.c (revision 40ef9009116dd37656783aaadc8782c1d8bfb056)
1*40ef9009SDavid du Colombier /*
2*40ef9009SDavid du Colombier  * The authors of this software are Rob Pike and Ken Thompson.
3*40ef9009SDavid du Colombier  *              Copyright (c) 2002 by Lucent Technologies.
4*40ef9009SDavid du Colombier  * Permission to use, copy, modify, and distribute this software for any
5*40ef9009SDavid du Colombier  * purpose without fee is hereby granted, provided that this entire notice
6*40ef9009SDavid du Colombier  * is included in all copies of any software which is or includes a copy
7*40ef9009SDavid du Colombier  * or modification of this software and in all copies of the supporting
8*40ef9009SDavid du Colombier  * documentation for such software.
9*40ef9009SDavid du Colombier  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
10*40ef9009SDavid du Colombier  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
11*40ef9009SDavid du Colombier  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
12*40ef9009SDavid du Colombier  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
13*40ef9009SDavid du Colombier  */
14*40ef9009SDavid du Colombier #include <stdarg.h>
15*40ef9009SDavid du Colombier #include <string.h>
16*40ef9009SDavid du Colombier #include "utf.h"
17*40ef9009SDavid du Colombier #include "utfdef.h"
18*40ef9009SDavid du Colombier 
19*40ef9009SDavid du Colombier 
20*40ef9009SDavid du Colombier /*
21*40ef9009SDavid du Colombier  * Return pointer to first occurrence of s2 in s1,
22*40ef9009SDavid du Colombier  * 0 if none
23*40ef9009SDavid du Colombier  */
24*40ef9009SDavid du Colombier char*
utfutf(char * s1,char * s2)25*40ef9009SDavid du Colombier utfutf(char *s1, char *s2)
26*40ef9009SDavid du Colombier {
27*40ef9009SDavid du Colombier 	char *p;
28*40ef9009SDavid du Colombier 	long f, n1, n2;
29*40ef9009SDavid du Colombier 	Rune r;
30*40ef9009SDavid du Colombier 
31*40ef9009SDavid du Colombier 	n1 = chartorune(&r, s2);
32*40ef9009SDavid du Colombier 	f = r;
33*40ef9009SDavid du Colombier 	if(f <= Runesync)		/* represents self */
34*40ef9009SDavid du Colombier 		return strstr(s1, s2);
35*40ef9009SDavid du Colombier 
36*40ef9009SDavid du Colombier 	n2 = strlen(s2);
37*40ef9009SDavid du Colombier 	for(p=s1; p=utfrune(p, f); p+=n1)
38*40ef9009SDavid du Colombier 		if(strncmp(p, s2, n2) == 0)
39*40ef9009SDavid du Colombier 			return p;
40*40ef9009SDavid du Colombier 	return 0;
41*40ef9009SDavid du Colombier }
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