1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. 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 8.1 (Berkeley) 6/4/93 37.\" $FreeBSD$ 38.\" 39.Dd November 28, 2001 40.Dt STRTOUL 3 41.Os 42.Sh NAME 43.Nm strtoul , strtoull , strtoumax , strtouq 44.Nd "convert a string to an" 45.Vt "unsigned long" , "unsigned long long" , uintmax_t , 46or 47.Vt u_quad_t 48integer 49.Sh LIBRARY 50.Lb libc 51.Sh SYNOPSIS 52.In stdlib.h 53.In limits.h 54.Ft "unsigned long" 55.Fn strtoul "const char * restrict nptr" "char ** restrict endptr" "int base" 56.Ft "unsigned long long" 57.Fn strtoull "const char * restrict nptr" "char ** restrict endptr" "int base" 58.In inttypes.h 59.Ft uintmax_t 60.Fn strtoumax "const char * restrict nptr" "char ** restrict endptr" "int base" 61.In sys/types.h 62.In stdlib.h 63.In limits.h 64.Ft u_quad_t 65.Fn strtouq "const char *nptr" "char **endptr" "int base" 66.Sh DESCRIPTION 67The 68.Fn strtoul 69function 70converts the string in 71.Fa nptr 72to an 73.Vt "unsigned long" 74value. 75The 76.Fn strtoull 77function 78converts the string in 79.Fa nptr 80to an 81.Vt "unsigned long long" 82value. 83The 84.Fn strtoumax 85function 86converts the string in 87.Fa nptr 88to an 89.Vt uintmax_t 90value. 91The 92.Fn strtouq 93function 94converts the string in 95.Fa nptr 96to a 97.Vt u_quad_t 98value. 99The conversion is done according to the given 100.Fa base , 101which must be between 2 and 36 inclusive, 102or be the special value 0. 103.Pp 104The string may begin with an arbitrary amount of white space 105(as determined by 106.Xr isspace 3 ) 107followed by a single optional 108.Ql + 109or 110.Ql - 111sign. 112If 113.Fa base 114is zero or 16, 115the string may then include a 116.Dq Li 0x 117prefix, 118and the number will be read in base 16; otherwise, a zero 119.Fa base 120is taken as 10 (decimal) unless the next character is 121.Ql 0 , 122in which case it is taken as 8 (octal). 123.Pp 124The remainder of the string is converted to an 125.Vt "unsigned long" 126value in the obvious manner, 127stopping at the end of the string 128or at the first character that does not produce a valid digit 129in the given base. 130(In bases above 10, the letter 131.Ql A 132in either upper or lower case 133represents 10, 134.Ql B 135represents 11, and so forth, with 136.Ql Z 137representing 35.) 138.Pp 139If 140.Fa endptr 141is not 142.Dv NULL , 143.Fn strtoul 144stores the address of the first invalid character in 145.Fa *endptr . 146If there were no digits at all, however, 147.Fn strtoul 148stores the original value of 149.Fa nptr 150in 151.Fa *endptr . 152(Thus, if 153.Fa *nptr 154is not 155.Ql \e0 156but 157.Fa **endptr 158is 159.Ql \e0 160on return, the entire string was valid.) 161.Sh RETURN VALUES 162The 163.Fn strtoul , 164.Fn strtoull , 165.Fn strtoumax 166and 167.Fn strtouq 168functions 169return either the result of the conversion 170or, if there was a leading minus sign, 171the negation of the result of the conversion, 172unless the original (non-negated) value would overflow; 173in the latter case, 174.Fn strtoul 175returns 176.Dv ULONG_MAX , 177.Fn strtoull 178returns 179.Dv ULLONG_MAX , 180.Fn strtoumax 181returns 182.Dv UINTMAX_MAX , 183and 184.Fn strtouq 185returns 186.Dv ULLONG_MAX . 187In all cases, 188.Va errno 189is set to 190.Er ERANGE . 191If no conversion could be performed, 0 is returned and 192the global variable 193.Va errno 194is set to 195.Er EINVAL 196(the last feature is not portable across all platforms). 197.Sh ERRORS 198.Bl -tag -width Er 199.It Bq Er EINVAL 200The value of 201.Fa base 202is not supported or 203no conversion could be performed 204(the last feature is not portable across all platforms). 205.It Bq Er ERANGE 206The given string was out of range; the value converted has been clamped. 207.El 208.Sh SEE ALSO 209.Xr strtol 3 , 210.Xr wcstoul 3 211.Sh STANDARDS 212The 213.Fn strtoul 214function 215conforms to 216.St -isoC . 217The 218.Fn strtoull 219and 220.Fn strtoumax 221functions 222conform to 223.St -isoC-99 . 224The 225.Bx 226.Fn strtouq 227function is deprecated. 228