1.\" $NetBSD: atoi.3,v 1.8 2002/08/20 15:30:07 wiz Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the American National Standards Committee X3, on Information 8.\" Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the University of 21.\" California, Berkeley and its contributors. 22.\" 4. Neither the name of the University nor the names of its contributors 23.\" may be used to endorse or promote products derived from this software 24.\" without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36.\" SUCH DAMAGE. 37.\" 38.\" from: @(#)atoi.3 8.1 (Berkeley) 6/4/93 39.\" 40.Dd June 4, 1993 41.Dt ATOI 3 42.Os 43.Sh NAME 44.Nm atoi 45.Nd convert 46.Tn ASCII 47string to integer 48.Sh LIBRARY 49.Lb libc 50.Sh SYNOPSIS 51.Fd #include \*[Lt]stdlib.h\*[Gt] 52.Ft int 53.Fn atoi "const char *nptr" 54.Sh DESCRIPTION 55The 56.Fn atoi 57function converts the initial portion of the string pointed to by 58.Em nptr 59to 60.Em integer 61representation. 62.Pp 63It is equivalent to: 64.Bd -literal -offset indent 65(int)strtol(nptr, (char **)NULL, 10); 66.Ed 67.Sh SEE ALSO 68.Xr atof 3 , 69.Xr atol 3 , 70.Xr strtod 3 , 71.Xr strtol 3 , 72.Xr strtoul 3 73.Sh STANDARDS 74The 75.Fn atoi 76function conforms to 77.St -ansiC . 78.Sh CAVEATS 79.Nm 80does no overflow checking, handles unsigned numbers poorly, 81and handles strings containing trailing extra characters 82(like 83.Dq 123abc ) 84poorly. 85Careful use of 86.Xr strtol 3 87and 88.Xr strtoul 3 89can alleviate these problems. 90