1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" Chris Torek and the American National Standards Committee X3, 6.\" on Information Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" from: @(#)strtol.3 5.3 (Berkeley) 6/29/91 37.\" $Id: strtol.3,v 1.3 1993/11/29 22:07:20 jtc Exp $ 38.\" 39.Dd June 29, 1991 40.Dt STRTOL 3 41.Os 42.Sh NAME 43.Nm strtol 44.Nd convert string value to a long integer 45.Sh SYNOPSIS 46.Fd #include <stdlib.h> 47.Fd #include <limits.h> 48.Ft long 49.Fn strtol "char *nptr" "char **endptr" "int base" 50.Sh DESCRIPTION 51The 52.Fn strtol 53function 54converts the string in 55.Fa nptr 56to a 57.Em long 58value according to the given 59.Fa base , 60which must be between 2 and 36 inclusive, 61or be the special value 0. 62.Pp 63The string may begin with an arbitrary amount of white space 64(as determined by 65.Xr isspace 3 ) 66followed by a single optional 67.Ql + 68or 69.Ql - 70sign. 71If 72.Fa base 73is zero or 16, 74the string may then include a 75.Ql 0x 76prefix, 77and the number will be read in base 16; otherwise, a zero 78.Fa base 79is taken as 10 (decimal) unless the next character is 80.Ql 0 , 81in which case it is taken as 8 (octal). 82.Pp 83The remainder of the string is converted to a 84.Em long 85value in the obvious manner, 86stopping at the first character which is not a valid digit 87in the given base. 88(In bases above 10, the letter 89.Ql A 90in either upper or lower case 91represents 10, 92.Ql B 93represents 11, and so forth, with 94.Ql Z 95representing 35.) 96.Pp 97If 98.Fa endptr 99is non nil, 100.Fn strtol 101stores the address of the first invalid character in 102.Fa *endptr . 103If there were no digits at all, however, 104.Fn strtol 105stores the original value of 106.Fa nptr 107in 108.Fa *endptr . 109(Thus, if 110.Fa *nptr 111is not 112.Ql \e0 113but 114.Fa **endptr 115is 116.Ql \e0 117on return, the entire string was valid.) 118.Sh RETURN VALUES 119The 120.Fn strtol 121function 122returns the result of the conversion, 123unless the value would underflow or overflow. 124If an underflow occurs, 125.Fn strtol 126returns 127.Dv LONG_MIN . 128If an overflow occurs, 129.Fn strtol 130returns 131.Dv LONG_MAX . 132In both cases, 133.Va errno 134is set to 135.Er ERANGE . 136.Sh ERRORS 137.Bl -tag -width Er 138.It Bq Er ERANGE 139The given string was out of range; the value converted has been clamped. 140.El 141.Sh SEE ALSO 142.Xr atof 3 , 143.Xr atoi 3 , 144.Xr atol 3 , 145.Xr strtod 3 , 146.Xr strtoul 3 147.Sh STANDARDS 148The 149.Fn strtol 150function 151conforms to 152.St -ansiC . 153.Sh BUGS 154Ignores the current locale. 155