String.indexOf function in C
Is there a C library function that will return the index of a character in a string?
So far, all I've found are functions like strstr that will return the found char *, not it's location in the original string.
strstr
returns a pointer to the found character, so you could use pointer arithmetic: (Note: this code not tested for its ability to compile, it's one step away from pseudocode.)
char * source = "test string"; /* assume source address is */
/* 0x10 for example */
char * found = strstr( source, "in" ); /* should return 0x18 */
if (found != NULL) /* strstr returns NULL if item not found */
{
int index = found - source; /* index is 8 */
/* source[8] gets you "i" */
}
I think that
size_t strcspn ( const char * str1, const char * str2 );
is what you want. Here is an example pulled from here:
/* strcspn example */
#include <stdio.h>
#include <string.h>
int main ()
{
char str[] = "fcba73";
char keys[] = "1234567890";
int i;
i = strcspn (str,keys);
printf ("The first number in str is at position %d.\n",i+1);
return 0;
}
EDIT: strchr is better only for one char. Pointer aritmetics says "Hellow!":
char *pos = strchr (myString, '#');
int pos = pos ? pos - myString : -1;
Important: strchr () returns NULL if no string is found