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.\" @(#)strtol.3 8.1 (Berkeley) 6/4/93 37.\" $FreeBSD$ 38.\" 39.Dd November 28, 2001 40.Dt STRTOL 3 41.Os 42.Sh NAME 43.Nm strtol , strtoll , strtoimax , strtoq 44.Nd "convert a string value to a" 45.Vt long , "long long" , intmax_t 46or 47.Vt quad_t 48integer 49.Sh LIBRARY 50.Lb libc 51.Sh SYNOPSIS 52.In stdlib.h 53.In limits.h 54.Ft long 55.Fn strtol "const char *nptr" "char **endptr" "int base" 56.Ft long long 57.Fn strtoll "const char *nptr" "char **endptr" "int base" 58.In inttypes.h 59.Ft intmax_t 60.Fn strtoimax "const char *nptr" "char **endptr" "int base" 61.In sys/types.h 62.In stdlib.h 63.In limits.h 64.Ft quad_t 65.Fn strtoq "const char *nptr" "char **endptr" "int base" 66.Sh DESCRIPTION 67The 68.Fn strtol 69function 70converts the string in 71.Fa nptr 72to a 73.Vt long 74value. 75The 76.Fn strtoll 77function 78converts the string in 79.Fa nptr 80to a 81.Vt "long long" 82value. 83The 84.Fn strtoimax 85function 86converts the string in 87.Fa nptr 88to an 89.Vt intmax_t 90value. 91The 92.Fn strtoq 93function 94converts the string in 95.Fa nptr 96to a 97.Vt 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 a 125.Vt long , "long long" , intmax_t 126or 127.Vt quad_t 128value in the obvious manner, 129stopping at the first character which is not a valid digit 130in the given base. 131(In bases above 10, the letter 132.Ql A 133in either upper or lower case 134represents 10, 135.Ql B 136represents 11, and so forth, with 137.Ql Z 138representing 35.) 139.Pp 140If 141.Fa endptr 142is not 143.Dv NULL , 144.Fn strtol 145stores the address of the first invalid character in 146.Fa *endptr . 147If there were no digits at all, however, 148.Fn strtol 149stores the original value of 150.Fa nptr 151in 152.Fa *endptr . 153(Thus, if 154.Fa *nptr 155is not 156.Ql \e0 157but 158.Fa **endptr 159is 160.Ql \e0 161on return, the entire string was valid.) 162.Sh RETURN VALUES 163The 164.Fn strtol , 165.Fn strtoll , 166.Fn strtoimax 167and 168.Fn strtoq 169functions 170return the result of the conversion, 171unless the value would underflow or overflow. 172If no conversion could be performed, 0 is returned and 173the global variable 174.Va errno 175is set to 176.Er EINVAL . 177If an overflow or underflow occurs, 178.Va errno 179is set to 180.Er ERANGE 181and the function return value is clamped according 182to the following table. 183.Bl -column -offset indent ".Fn strtoimax" ".Sy overflow" ".Sy underflow" 184.It Sy Function Ta Sy overflow Ta Sy underflow 185.It Fn strtol Ta Dv LONG_MIN Ta Dv LONG_MAX 186.It Fn strtoll Ta Dv LLONG_MIN Ta Dv LLONG_MAX 187.It Fn strtoimax Ta Dv INTMAX_MIN Ta Dv INTMAX_MAX 188.It Fn strtoq Ta Dv LLONG_MIN Ta Dv LLONG_MAX 189.El 190.Sh ERRORS 191.Bl -tag -width Er 192.It Bq Er EINVAL 193The value of 194.Fa base 195is not supported or 196no conversion could be performed. 197.It Bq Er ERANGE 198The given string was out of range; the value converted has been clamped. 199.El 200.Sh SEE ALSO 201.Xr atof 3 , 202.Xr atoi 3 , 203.Xr atol 3 , 204.Xr strtod 3 , 205.Xr strtoul 3 206.Sh STANDARDS 207The 208.Fn strtol 209function 210conforms to 211.St -isoC . 212The 213.Fn strtoll 214and 215.Fn strtoimax 216functions 217conform to 218.St -isoC-99 . 219The 220.Bx 221.Fn strtoq 222function is deprecated. 223