ATOI

Section: Linux Programmer's Manual (3 )
Updated: 2000-12-17
Index
Return to Main Contents

NAME

atoi, atol, atoll, atoq - convert a string to an integer.

SYNOPSIS

#include <stdlib.h>

int atoi(const char *nptr);


long atol(const char *nptr);


long long atoll(const char *nptr);


long long atoq(const char *nptr);

DESCRIPTION

The atoi() function converts the initial portion of the string pointed to by nptr to int. The behaviour is the same as

: strtol(nptr, (char **)NULL, 10);

except that atoi() does not detect errors.

The atol() and atoll() functions behave the same as atoi(), except that they convert the initial portion of the string to their return type of long or long long. atoq() is an obsolete name for atoll().

RETURN VALUE

The converted value.

CONFORMING TO

SVID 3, POSIX.1, BSD 4.3, ISO/IEC 9899. ISO/IEC 9899:1990 (C89) and POSIX.1 (1996 edition) include the functions atoi() and atol() only; C99 adds the function atoll().

NOTES

The non-standard atoq() function is not present in libc 4.6.27 or glibc 2, but is present in libc5 and libc 4.7 (though only as an inline function in <stdlib.h> until libc 5.4.44). The atoll() function is present in glibc 2 since version 2.0.2, but not in libc4 or libc5.

This document was created by man2html, using the manual pages.
Time: 00:49:21 GMT, January 21, 2025