STRTOL(3) BSD Library Functions Manual STRTOL(3)
NAME
strtol, strtoll, strtoimax, strtoq -- convert string value to a long, long long, intmax_t or quad_t integer
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdlib.h>
#include <limits.h>
long int
strtol(const char * restrict nptr, char ** restrict endptr, int base);
long long int
strtoll(const char * restrict nptr, char ** restrict endptr, int base);
#include <inttypes.h>
intmax_t
strtoimax(const char * restrict nptr, char ** restrict endptr, int base);
#include <sys/types.h>
#include <stdlib.h>
#include <limits.h>
quad_t
strtoq(const char * restrict nptr, char ** restrict endptr, int base);
DESCRIPTION
The strtol() function converts the string in nptr to a long int value. The strtoll() function converts the string in nptr to a long long int
value. The strtoimax() function converts the string in nptr to an intmax_t value. The strtoq() function converts the string in nptr to a
quad_t 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 '