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: @(#)strtoul.3 5.3 (Berkeley) 6/29/91 37.\" $Id: strtoul.3,v 1.4 1993/11/29 22:07:24 jtc Exp $ 38.\" 39.Dd June 29, 1991 40.Dt STRTOUL 3 41.Os 42.Sh NAME 43.Nm strtoul 44.Nd convert a string to an unsigned long integer 45.Sh SYNOPSIS 46.Fd #include <stdlib.h> 47.Fd #include <limits.h> 48.Ft unsigned long 49.Fn strtoul "const char *nptr" "char **endptr" "int base" 50.Sh DESCRIPTION 51The 52.Fn strtoul 53function 54converts the string in 55.Fa nptr 56to an 57.Em unsigned 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 an 84.Em unsigned long 85value in the obvious manner, 86stopping at the end of the string 87or at the first character that does not produce a valid digit 88in the given base. 89(In bases above 10, the letter 90.Ql A 91in either upper or lower case 92represents 10, 93.Ql B 94represents 11, and so forth, with 95.Ql Z 96representing 35.) 97.Pp 98If 99.Fa endptr 100is non nil, 101.Fn strtoul 102stores the address of the first invalid character in 103.Fa *endptr . 104If there were no digits at all, however, 105.Fn strtoul 106stores the original value of 107.Fa nptr 108in 109.Fa *endptr . 110(Thus, if 111.Fa *nptr 112is not 113.Ql \e0 114but 115.Fa **endptr 116is 117.Ql \e0 118on return, the entire string was valid.) 119.Sh RETURN VALUES 120The 121.Fn strtoul 122function 123returns either the result of the conversion 124or, if there was a leading minus sign, 125the negation of the result of the conversion, 126unless the original (non-negated) value would overflow; 127in the latter case, 128.Fn strtoul 129returns 130.Dv ULONG_MAX 131and sets the global variable 132.Va errno 133to 134.Er ERANGE . 135.Sh ERRORS 136.Bl -tag -width Er 137.It Bq Er ERANGE 138The given string was out of range; the value converted has been clamped. 139.El 140.Sh SEE ALSO 141.Xr strtol 3 142.Sh STANDARDS 143The 144.Fn strtoul 145function 146conforms to 147.St -ansiC . 148.Sh BUGS 149Ignores the current locale. 150