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. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)strtoul.3 8.1 (Berkeley) 6/4/93 33.\" 34.Dd November 28, 2001 35.Dt STRTOUL 3 36.Os 37.Sh NAME 38.Nm strtoul , strtoull , strtoumax , strtouq 39.Nd "convert a string to an" 40.Vt "unsigned long" , "unsigned long long" , uintmax_t , 41or 42.Vt u_quad_t 43integer 44.Sh LIBRARY 45.Lb libc 46.Sh SYNOPSIS 47.In stdlib.h 48.In limits.h 49.Ft "unsigned long" 50.Fn strtoul "const char * restrict nptr" "char ** restrict endptr" "int base" 51.Ft "unsigned long long" 52.Fn strtoull "const char * restrict nptr" "char ** restrict endptr" "int base" 53.In inttypes.h 54.Ft uintmax_t 55.Fn strtoumax "const char * restrict nptr" "char ** restrict endptr" "int base" 56.In sys/types.h 57.In stdlib.h 58.In limits.h 59.Ft u_quad_t 60.Fn strtouq "const char *nptr" "char **endptr" "int base" 61.Sh DESCRIPTION 62The 63.Fn strtoul 64function 65converts the string in 66.Fa nptr 67to an 68.Vt "unsigned long" 69value. 70The 71.Fn strtoull 72function 73converts the string in 74.Fa nptr 75to an 76.Vt "unsigned long long" 77value. 78The 79.Fn strtoumax 80function 81converts the string in 82.Fa nptr 83to an 84.Vt uintmax_t 85value. 86The 87.Fn strtouq 88function 89converts the string in 90.Fa nptr 91to a 92.Vt u_quad_t 93value. 94The conversion is done according to the given 95.Fa base , 96which must be between 2 and 36 inclusive, 97or be the special value 0. 98.Pp 99The string may begin with an arbitrary amount of white space 100(as determined by 101.Xr isspace 3 ) 102followed by a single optional 103.Ql + 104or 105.Ql - 106sign. 107If 108.Fa base 109is zero or 16, 110the string may then include a 111.Dq Li 0x 112prefix, 113and the number will be read in base 16; otherwise, a zero 114.Fa base 115is taken as 10 (decimal) unless the next character is 116.Ql 0 , 117in which case it is taken as 8 (octal). 118.Pp 119The remainder of the string is converted to an 120.Vt "unsigned long" 121value in the obvious manner, 122stopping at the end of the string 123or at the first character that does not produce a valid digit 124in the given base. 125(In bases above 10, the letter 126.Ql A 127in either upper or lower case 128represents 10, 129.Ql B 130represents 11, and so forth, with 131.Ql Z 132representing 35.) 133.Pp 134If 135.Fa endptr 136is not 137.Dv NULL , 138.Fn strtoul 139stores the address of the first invalid character in 140.Fa *endptr . 141If there were no digits at all, however, 142.Fn strtoul 143stores the original value of 144.Fa nptr 145in 146.Fa *endptr . 147(Thus, if 148.Fa *nptr 149is not 150.Ql \e0 151but 152.Fa **endptr 153is 154.Ql \e0 155on return, the entire string was valid.) 156.Sh RETURN VALUES 157The 158.Fn strtoul , 159.Fn strtoull , 160.Fn strtoumax 161and 162.Fn strtouq 163functions 164return either the result of the conversion 165or, if there was a leading minus sign, 166the negation of the result of the conversion, 167unless the original (non-negated) value would overflow; 168in the latter case, 169.Fn strtoul 170returns 171.Dv ULONG_MAX , 172.Fn strtoull 173returns 174.Dv ULLONG_MAX , 175.Fn strtoumax 176returns 177.Dv UINTMAX_MAX , 178and 179.Fn strtouq 180returns 181.Dv ULLONG_MAX . 182In all cases, 183.Va errno 184is set to 185.Er ERANGE . 186If no conversion could be performed, 0 is returned and 187the global variable 188.Va errno 189is set to 190.Er EINVAL 191(the last feature is not portable across all platforms). 192.Sh ERRORS 193.Bl -tag -width Er 194.It Bq Er EINVAL 195The value of 196.Fa base 197is not supported or 198no conversion could be performed 199(the last feature is not portable across all platforms). 200.It Bq Er ERANGE 201The given string was out of range; the value converted has been clamped. 202.El 203.Sh SEE ALSO 204.Xr strtol 3 , 205.Xr strtonum 3 , 206.Xr wcstoul 3 207.Sh STANDARDS 208The 209.Fn strtoul 210function 211conforms to 212.St -isoC . 213The 214.Fn strtoull 215and 216.Fn strtoumax 217functions 218conform to 219.St -isoC-99 . 220The 221.Bx 222.Fn strtouq 223function is deprecated. 224