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);

   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, 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 3.53 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/.



GNU                                         2012-08-03                                    ATOI(3)