atol() -- General Function (libc)

Convert ASCII strings to long integers
#include <stdlib.h>
long atol(string) char *string;

atol() converts  the argument string to a binary  representation of a long.
string may contain a leading sign  (but no trailing sign) and any number of
decimal digits.  atol() ignores  leading blanks and tabs; it stops scanning
when it encounters any non-numeral other than the leading sign, and returns
the resulting long.

Example


#include <stdlib.h>

main()
{
    extern char *gets();
    extern long atol();
    char string[64];

    for(;;) {
        printf("Enter numeric string: ");
        if(gets(string))
            printf("%ld\n", atol(string));
        else
            break;
    }
}

See Also

atof(),
atoi(),
float,
libc,
long,
printf(),
scanf(),
stdlib.h
ANSI Standard, §7.10.1.3
POSIX Standard, §8.1

Notes

No overflow  checks are  performed.  atol() returns  zero if it  receives a
string it cannot interpret.

© 2012 by Stephen A. Ness