ATOI
Section: Linux Programmer's Manual (3)
Updated: 2010-09-20
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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);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
atoll():
-
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or
cc -std=c99
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, (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
SVr4, POSIX.1-2001, 4.3BSD, C99.
C89 and
POSIX.1-1996 include the functions
atoi()
and
atol()
only.
atoq()
is a GNU extension.
NOTES
The nonstandard
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.
SEE ALSO
atof(3),
strtod(3),
strtol(3),
strtoul(3)
COLOPHON
This page is part of release 3.27 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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