strspn() Find First Substring
#include <string.h> Required for declarations only
int strspn(string1,string2);
char *string1; Searched string
char *string2; Character set
strspn() tests whether the first substring (i.e., the substring
beginning at the start of 'string1') in 'string1' consists entirely
of characters from character set 'string2'. (It does this by
searching 'string1' for the first occurrence of a character that is
not also in 'string2'.)
Returns: The index in 'string1' of the first character past the
substring that contains only characters from 'string2'.
This is equal to the first character in 'string1' that is
not among the characters in 'string2'. Looking at it
another way, the index value is equal to the length of
the substring of 'string1' that is made up of characters
from 'string2'.
-------------------------------- Example ---------------------------------
The following statements check whether 'string' begins with a vowel.
#include <string.h>
int rslt;
char *string = "imagination";
char *charset = "aeiou";
main()
{
if((rslt = strspn(string,charset)) > 0)
printf("string begins with a vowel\n");
}
Seealso:
This page last updated on Fri Nov 30 10:48:32 MSK 2001
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