bsd man page for strtol

STRTOL(3)						     Library Functions Manual							 STRTOL(3)

NAME
       strtol - convert string value to a long

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

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

DESCRIPTION
       The  strtol()  function	converts  the  string  in nptr to a long value.  The conversion is done according to the given base, which must be
       between 2 and 36 inclusive, or be the special value 0.

       The string may begin with an arbitrary amount of white space (as determined by isspace(3)) followed by a single optional `+' or	`-'  sign.
       If  base  is zero or 16, the string may then include a `0x' prefix, and the number will be read in base 16; otherwise, a zero base is taken
       as 10 (decimal) unless the next character is `0', in which case it is taken as 8 (octal).

       The remainder of the string is converted to a long value in the obvious manner, stopping at the first character which is not a valid  digit
       in  the	given base.  (In bases above 10, the letter `A' in either upper or lower case represents 10, `B' represents 11, and so forth, with
       `Z' representing 35.)

       If endptr is non nil, strtol() stores the address of the first invalid character in *endptr .  If there were no	digits	at  all,  however,
       strtol()  stores  the original value of nptr in *endptr.  (Thus, if *nptr is not `' but **endptr is `' on return, the entire string was
       valid.)

RETURN VALUES
       The strtol() function returns the result of the conversion, unless the value would underflow or overflow.  If an underflow occurs, strtol()
       returns LONG_MIN.  If an overflow occurs, strtol() returns LONG_MAX.  In both cases, errno is set to ERANGE .

ERRORS
       [ERANGE]       The given string was out of range; the value converted has been clamped.

SEE ALSO
       atof(3), atoi(3), atol(3), strtoul(3)

STANDARDS
       The strtol() function conforms to ANSI C X3.159-1989 (``ANSI C'').

BUGS
       Ignores the current locale.

4.4 Berkeley Distribution					 January 12, 1996							 STRTOL(3)