atol() v/s. strtol()

Question

What is the difference between atol() & strtol()?

According to their man pages, they seem to have the same effect as well as matching arguments:

Answer 1

In new code I would always use strtol. It has error handling and the endptr argument allows you to see which part of the string was used.

The C99 standard states about the ato* functions:

Except for the behavior on error,they equivalent to

atoi: (int)strtol(nptr,(char **)NULL, 10)
atol: strtol(nptr,(char **)NULL, 10)
atoll: strtoll(nptr, (char **)NULL, 10)