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.\" 4. 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.\" @(#)strtol.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/stdlib/strtol.3,v 1.23 2007/04/10 11:17:00 ru Exp $ 34.\" $DragonFly: src/lib/libc/stdlib/strtol.3,v 1.5 2007/04/10 21:09:00 swildner Exp $ 35.\" 36.Dd November 2, 2006 37.Dt STRTOL 3 38.Os 39.Sh NAME 40.Nm strtol , strtoll , strtoimax , strtoq 41.Nd "convert a string value to a" 42.Vt long , "long long" , intmax_t 43or 44.Vt quad_t 45integer 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In stdlib.h 50.In limits.h 51.Ft long 52.Fn strtol "const char * restrict nptr" "char ** restrict endptr" "int base" 53.Ft long long 54.Fn strtoll "const char * restrict nptr" "char ** restrict endptr" "int base" 55.In inttypes.h 56.Ft intmax_t 57.Fn strtoimax "const char * restrict nptr" "char ** restrict endptr" "int base" 58.In sys/types.h 59.In stdlib.h 60.In limits.h 61.Ft quad_t 62.Fn strtoq "const char *nptr" "char **endptr" "int base" 63.Sh DESCRIPTION 64The 65.Fn strtol 66function 67converts the string in 68.Fa nptr 69to a 70.Vt long 71value. 72The 73.Fn strtoll 74function 75converts the string in 76.Fa nptr 77to a 78.Vt "long long" 79value. 80The 81.Fn strtoimax 82function 83converts the string in 84.Fa nptr 85to an 86.Vt intmax_t 87value. 88The 89.Fn strtoq 90function 91converts the string in 92.Fa nptr 93to a 94.Vt quad_t 95value. 96The conversion is done according to the given 97.Fa base , 98which must be between 2 and 36 inclusive, 99or be the special value 0. 100.Pp 101The string may begin with an arbitrary amount of white space 102(as determined by 103.Xr isspace 3 ) 104followed by a single optional 105.Ql + 106or 107.Ql - 108sign. 109If 110.Fa base 111is zero or 16, 112the string may then include a 113.Dq Li 0x 114prefix, 115and the number will be read in base 16; otherwise, a zero 116.Fa base 117is taken as 10 (decimal) unless the next character is 118.Ql 0 , 119in which case it is taken as 8 (octal). 120.Pp 121The remainder of the string is converted to a 122.Vt long , "long long" , intmax_t 123or 124.Vt quad_t 125value in the obvious manner, 126stopping at the first character which is not a valid digit 127in the given base. 128(In bases above 10, the letter 129.Ql A 130in either upper or lower case 131represents 10, 132.Ql B 133represents 11, and so forth, with 134.Ql Z 135representing 35.) 136.Pp 137If 138.Fa endptr 139is not 140.Dv NULL , 141.Fn strtol 142stores the address of the first invalid character in 143.Fa *endptr . 144If there were no digits at all, however, 145.Fn strtol 146stores the original value of 147.Fa nptr 148in 149.Fa *endptr . 150(Thus, if 151.Fa *nptr 152is not 153.Ql \e0 154but 155.Fa **endptr 156is 157.Ql \e0 158on return, the entire string was valid.) 159.Sh RETURN VALUES 160The 161.Fn strtol , 162.Fn strtoll , 163.Fn strtoimax 164and 165.Fn strtoq 166functions 167return the result of the conversion, 168unless the value would underflow or overflow. 169If no conversion could be performed, 0 is returned and 170the global variable 171.Va errno 172is set to 173.Er EINVAL 174(the last feature is not portable across all platforms). 175If an overflow or underflow occurs, 176.Va errno 177is set to 178.Er ERANGE 179and the function return value is clamped according 180to the following table. 181.Bl -column -offset indent ".Fn strtoimax" ".Sy underflow" ".Sy overflow" 182.It Sy Function Ta Sy underflow Ta Sy overflow 183.It Fn strtol Ta Dv LONG_MIN Ta Dv LONG_MAX 184.It Fn strtoll Ta Dv LLONG_MIN Ta Dv LLONG_MAX 185.It Fn strtoimax Ta Dv INTMAX_MIN Ta Dv INTMAX_MAX 186.It Fn strtoq Ta Dv LLONG_MIN Ta Dv LLONG_MAX 187.El 188.Sh ERRORS 189.Bl -tag -width Er 190.It Bq Er EINVAL 191The value of 192.Fa base 193is not supported or 194no conversion could be performed 195(the last feature is not portable across all platforms). 196.It Bq Er ERANGE 197The given string was out of range; the value converted has been clamped. 198.El 199.Sh SEE ALSO 200.Xr atof 3 , 201.Xr atoi 3 , 202.Xr atol 3 , 203.Xr strtod 3 , 204.Xr strtonum 3 , 205.Xr strtoul 3 , 206.Xr wcstol 3 207.Sh STANDARDS 208The 209.Fn strtol 210function 211conforms to 212.St -isoC . 213The 214.Fn strtoll 215and 216.Fn strtoimax 217functions 218conform to 219.St -isoC-99 . 220The 221.Bx 222.Fn strtoq 223function is deprecated. 224