ATOI(3) Linux Programmer's Manual ATOI(3)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
SVr4, POSIX.1-2001, 4.3BSD, C99. C89 and POSIX.1-1996 include the
functions atoi() and atol() only. atoq(3) is a GNU extension.
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 func‐
tion 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 ALSOatof(3), strtod(3), strtol(3), strtoul(3)GNU 2000-12-17 ATOI(3)
