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.\" @(#)strtoul.3 5.3 (Berkeley) 6/29/91 37.\" 38.Dd June 29, 1991 39.Dt STRTOUL 3 40.Os 41.Sh NAME 42.Nm strtoul 43.Nd convert a string to an unsigned long integer 44.Sh SYNOPSIS 45.Fd #include <stdlib.h> 46.Fd #include <limits.h> 47.Fn strtoul "const char *nptr" "char **endptr" "int base" 48.Sh DESCRIPTION 49The 50.Fn strtoul 51function 52converts the string in 53.Fa nptr 54to an 55.Em unsigned long 56value according to the given 57.Fa base , 58which must be between 2 and 36 inclusive, 59or be the special value 0. 60.Pp 61The string may begin with an arbitrary amount of white space 62(as determined by 63.Xr isspace 3 ) 64followed by a single optional 65.Ql + 66or 67.Ql - 68sign. 69If 70.Fa base 71is zero or 16, 72the string may then include a 73.Ql 0x 74prefix, 75and the number will be read in base 16; otherwise, a zero 76.Fa base 77is taken as 10 (decimal) unless the next character is 78.Ql 0 , 79in which case it is taken as 8 (octal). 80.Pp 81The remainder of the string is converted to an 82.Em unsigned long 83value in the obvious manner, 84stopping at the end of the string 85or at the first character that does not produce a valid digit 86in the given base. 87(In bases above 10, the letter 88.Ql A 89in either upper or lower case 90represents 10, 91.Ql B 92represents 11, and so forth, with 93.Ql Z 94representing 35.) 95.Pp 96If 97.Fa endptr 98is non nil, 99.Fn strtoul 100stores the address of the first invalid character in 101.Fa *endptr . 102If there were no digits at all, however, 103.Fn strtoul 104stores the original value of 105.Fa nptr 106in 107.Fa *endptr . 108(Thus, if 109.Fa *nptr 110is not 111.Ql \e0 112but 113.Fa **endptr 114is 115.Ql \e0 116on return, the entire string was valid.) 117.Sh RETURN VALUES 118The 119.Fn strtoul 120function 121returns either the result of the conversion 122or, if there was a leading minus sign, 123the negation of the result of the conversion, 124unless the original (non-negated) value would overflow; 125in the latter case, 126.Fn strtoul 127returns 128.Dv ULONG_MAX 129and sets the global variable 130.Va errno 131to 132.Er ERANGE . 133.Sh ERRORS 134.Bl -tag -width [ERANGE] 135.It Bq Er ERANGE 136The given string was out of range; the value converted has been clamped. 137.El 138.Sh SEE ALSO 139.Xr strtol 3 140.Sh STANDARDS 141The 142.Fn strtoul 143function 144conforms to 145.St -ansiC . 146.Sh BUGS 147Ignores the current locale. 148