1.\" $NetBSD: strtoul.3,v 1.7 1997/11/14 02:04:56 mrg Exp $ 2.\" 3.\" Copyright (c) 1990, 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Chris Torek and the American National Standards Committee X3, 8.\" on Information 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: @(#)strtoul.3 5.4 (Berkeley) 6/25/92 39.\" 40.Dd June 25, 1992 41.Dt STRTOUL 3 42.Os 43.Sh NAME 44.Nm strtoul , 45.Nm strtouq 46.Nd convert a string to an unsigned long or uquad_t integer 47.Sh SYNOPSIS 48.Fd #include <stdlib.h> 49.Fd #include <limits.h> 50.Ft unsigned long 51.Fn strtoul "const char *nptr" "char **endptr" "int base" 52 53.Fd #include <sys/types.h> 54.Fd #include <stdlib.h> 55.Fd #include <limits.h> 56.Ft u_quad_t 57.Fn strtouq "const char *nptr" "char **endptr" "int base" 58.Sh DESCRIPTION 59The 60.Fn strtoul 61function 62converts the string in 63.Fa nptr 64to an 65.Em unsigned long 66value. 67The 68.Fn strtouq 69function 70converts the string in 71.Fa nptr 72to a 73.Em u_quad_t 74value. 75The conversion is done according to the given 76.Fa base , 77which must be between 2 and 36 inclusive, 78or be the special value 0. 79.Pp 80The string may begin with an arbitrary amount of white space 81(as determined by 82.Xr isspace 3 ) 83followed by a single optional 84.Ql + 85or 86.Ql - 87sign. 88If 89.Fa base 90is zero or 16, 91the string may then include a 92.Ql 0x 93prefix, 94and the number will be read in base 16; otherwise, a zero 95.Fa base 96is taken as 10 (decimal) unless the next character is 97.Ql 0 , 98in which case it is taken as 8 (octal). 99.Pp 100The remainder of the string is converted to an 101.Em unsigned long 102value in the obvious manner, 103stopping at the end of the string 104or at the first character that does not produce a valid digit 105in the given base. 106(In bases above 10, the letter 107.Ql A 108in either upper or lower case 109represents 10, 110.Ql B 111represents 11, and so forth, with 112.Ql Z 113representing 35.) 114.Pp 115If 116.Fa endptr 117is non nil, 118.Fn strtoul 119stores the address of the first invalid character in 120.Fa *endptr . 121If there were no digits at all, however, 122.Fn strtoul 123stores the original value of 124.Fa nptr 125in 126.Fa *endptr . 127(Thus, if 128.Fa *nptr 129is not 130.Ql \e0 131but 132.Fa **endptr 133is 134.Ql \e0 135on return, the entire string was valid.) 136.Sh RETURN VALUES 137The 138.Fn strtoul 139function 140returns either the result of the conversion 141or, if there was a leading minus sign, 142the negation of the result of the conversion, 143unless the original (non-negated) value would overflow; 144in the latter case, 145.Fn strtoul 146returns 147.Dv ULONG_MAX 148and sets the global variable 149.Va errno 150to 151.Er ERANGE . 152.Sh ERRORS 153.Bl -tag -width Er 154.It Bq Er ERANGE 155The given string was out of range; the value converted has been clamped. 156.El 157.Sh SEE ALSO 158.Xr strtol 3 159.Sh STANDARDS 160The 161.Fn strtoul 162function 163conforms to 164.St -ansiC . 165.Sh BUGS 166Ignores the current locale. 167