ATOI(3) Linux Programmer's Manual ATOI(3)
NAME
atoi, atol, atoll - 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);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
atoll():
_ISOC99_SOURCE ||
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
DESCRIPTION
The atoi() function converts the initial portion of the string pointed
to by nptr to int. The behavior is the same as
strtol(nptr, 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.
RETURN VALUE
The converted value.
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(7).
+------------------------+---------------+----------------+
|Interface | Attribute | Value |
+------------------------+---------------+----------------+
|atoi(), atol(), atoll() | Thread safety | MT-Safe locale |
+------------------------+---------------+----------------+
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99, SVr4, 4.3BSD. C89 and POSIX.1-1996
include the functions atoi() and atol() only.
SEE ALSO
atof(3), strtod(3), strtol(3), strtoul(3)
COLOPHON
This page is part of release 5.07 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
GNU 2020-04-11 ATOI(3)