strspn

 

C

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Defined in header <string.h>
size_t strspn( const char *dest, const char *src );

Returns the length of the maximum initial segment of the byte string pointed to by dest, that consists of only the characters found in byte string pointed to by src.

Parameters

dest	-	pointer to the null-terminated byte string to be analyzed
src	-	pointer to the null-terminated byte string that contains the characters to search for

Return value

The length of the maximum initial segment that contains only characters from byte string pointed to by src

Example

run this code

char *string_find = "abcde312$#@";
char *lowal_pha = "qwertyuiopasdfghjklzxcvbnm";
printf("%i", strspn(string_find, low_alpha));

Output:

5

See also

strcspn	returns the length of the maximum initial segment that consists of only the characters not found in another byte string (function)
strpbrk	finds the first location of any character in one string, in another string (function)