C language: How to get the remaining string after using strtok() once

Question

My string is "A,B,C,D,E"
And the separator is ","
How can I get the remaining string after doing strtok() once, that is "B,C,D,E"

char a[] = "A,B,C,D,E";
char * separator = ",";
char * b = strtok(a,separator);
printf("a: %s\n", a);
printf("b: %s\n", b);

The output is:
a: A
b: A

But how to get the result
a: B,C,D,E
b: A

Thanks.

Answer 1

You can vary the set of delimiters, so simply pass an empty string:

char a[] = "A,B,C,D,E";
char * separator = ",";
char * b = strtok(a, separator);
printf("b: %s\n", b);
char * c = strtok(NULL, "");
printf("c: %s\n", c);

Answer 2

Don't use strtok() for this, since that's not what it's for.

Use strchr() to find the first separator, and go from there:

char a[] = "A,B,C,D,E";
const char separator = ',';
char * const sep_at = strchr(a, separator);
if(sep_at != NULL)
{
  *sep_at = '\0'; /* overwrite first separator, creating two strings. */
  printf("first part: '%s'\nsecond part: '%s'\n", a, sep_at + 1);
}