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52 lines
959 B
C
52 lines
959 B
C
/* Simple implementation of strstr for systems without it.
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This function is in the public domain. */
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/*
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NAME
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strstr -- locate first occurance of a substring
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SYNOPSIS
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#include <string.h>
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char *strstr (char *s1, char *s2)
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DESCRIPTION
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Locates the first occurance in the string pointed to by S1 of
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the string pointed to by S2. Returns a pointer to the substring
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found, or a NULL pointer if not found. If S2 points to a string
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with zero length, the function returns S1.
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BUGS
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*/
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/* FIXME: The above description is ANSI compiliant. This routine has not
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been validated to comply with it. -fnf */
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char *
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strstr (s1, s2)
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char *s1, *s2;
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{
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register char *p = s1;
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extern char *strchr ();
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extern int strncmp ();
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#if __GNUC__==2
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extern __SIZE_TYPE__ strlen ();
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#endif
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register int len = strlen (s2);
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for (; (p = strchr (p, *s2)) != 0; p++)
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{
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if (strncmp (p, s2, len) == 0)
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{
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return (p);
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}
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}
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return (0);
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}
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