C strcspn() Function – C tutorial

The strcspn() function scans the main string for the given string and returns the number of characters in the main string from beginning till the first matched character is found.

C strcspn() declaration

size_t strcspn(const char *str1, const char *str2)

str1 – The main string to be searched
str2 – The characters of this string is searched in the main string till the first matched character is found

Return value of function strcspn()

This function returns the number of characters in the main string that are found before a first matched character is found.

Function strcspn() example in C

#include <stdio.h>
#include <string.h>
int main () {
   const char str[20] = "aabbccddeeff"; 
   const char searchString[10] = "dxz";
   int loc;

   /* This function returns the number of characters present in the main string 
    * from beginning till the first matched character is found 
    */
   loc = strcspn(str, searchString);
   printf("The first matched char in string str1 is at: %d", (loc+1));
   return 0;
}

Output:

The first matched char in string str1 is at: 7

The characters that we are searching in the main string str are ‘d’, ‘x’ and ‘z’, the first matched character is found at the position 7 in the main string.

Related Posts:

1. C – strcat() function
2. C – strchr() function
3. C – strcmp() function
4. C – strcpy() function