Advanced UNIX Programming

The strtol(3) and strtoul(3) Functions

The function sscanf(3) calls upon the functions strtol(3) and strtoul(3) to carry out its dirty work. You can go right to the source by calling them. The synopses for strtol(3) and strtoul(3) are as follows:

#include <stdlib.h>
#include <limits.h>

long strtol(const char *nptr, char **endptr, int base);

unsigned long strtoul(const char *nptr, char **endptr, int base);

Macros from <limits.h> :
    LONG_MAX
    LONG_MIN
    ULONG_MAX
    LONGLONG_MAX
    LONGLONG_MIN
    ULONGLONG_MAX

The function strtol(3) converts a possibly signed integer within a character string to a long integer data type value. The function strtoul(3) is functionally identical, except that no sign is permitted, and the returned conversion value is an unsigned ...