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 1.2 1993/08/01 07:44:16 mycroft 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.Fn strtoul "const char *nptr" "char **endptr" "int base" 49.Sh DESCRIPTION 50The 51.Fn strtoul 52function 53converts the string in 54.Fa nptr 55to an 56.Em unsigned long 57value according to the given 58.Fa base , 59which must be between 2 and 36 inclusive, 60or be the special value 0. 61.Pp 62The string may begin with an arbitrary amount of white space 63(as determined by 64.Xr isspace 3 ) 65followed by a single optional 66.Ql + 67or 68.Ql - 69sign. 70If 71.Fa base 72is zero or 16, 73the string may then include a 74.Ql 0x 75prefix, 76and the number will be read in base 16; otherwise, a zero 77.Fa base 78is taken as 10 (decimal) unless the next character is 79.Ql 0 , 80in which case it is taken as 8 (octal). 81.Pp 82The remainder of the string is converted to an 83.Em unsigned long 84value in the obvious manner, 85stopping at the end of the string 86or at the first character that does not produce 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 strtoul 101stores the address of the first invalid character in 102.Fa *endptr . 103If there were no digits at all, however, 104.Fn strtoul 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 strtoul 121function 122returns either the result of the conversion 123or, if there was a leading minus sign, 124the negation of the result of the conversion, 125unless the original (non-negated) value would overflow; 126in the latter case, 127.Fn strtoul 128returns 129.Dv ULONG_MAX 130and sets the global variable 131.Va errno 132to 133.Er ERANGE . 134.Sh ERRORS 135.Bl -tag -width [ERANGE] 136.It Bq Er ERANGE 137The given string was out of range; the value converted has been clamped. 138.El 139.Sh SEE ALSO 140.Xr strtol 3 141.Sh STANDARDS 142The 143.Fn strtoul 144function 145conforms to 146.St -ansiC . 147.Sh BUGS 148Ignores the current locale. 149