1.\" Copyright (c) 1990, 1991 The Regents of the University of California. 2.\" 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 5.3 (Berkeley) 6/29/91 37.\" 38.Dd June 29, 1991 39.Dt STRTOL 3 40.Os 41.Sh NAME 42.Nm strtol 43.Nd convert string value to a long integer 44.Sh SYNOPSIS 45.Fd #include <stdlib.h> 46.Fd #include <limits.h> 47.Ft long 48.Fn strtol "char *nptr" "char **endptr" "int base" 49.Sh DESCRIPTION 50The 51.Fn strtol 52function 53converts the string in 54.Fa nptr 55to a 56.Em long 57value according to the given 58.Fa base , 59which must be between 2 and 36 inclusive, 60or be the special value 0. 61.Pp 62The string may begin with an arbitrary amount of white space 63(as determined by 64.Xr isspace 3 ) 65followed by a single optional 66.Ql + 67or 68.Ql - 69sign. 70If 71.Fa base 72is zero or 16, 73the string may then include a 74.Ql 0x 75prefix, 76and the number will be read in base 16; otherwise, a zero 77.Fa base 78is taken as 10 (decimal) unless the next character is 79.Ql 0 , 80in which case it is taken as 8 (octal). 81.Pp 82The remainder of the string is converted to a 83.Em long 84value in the obvious manner, 85stopping at the first character which is not a valid digit 86in the given base. 87(In bases above 10, the letter 88.Ql A 89in either upper or lower case 90represents 10, 91.Ql B 92represents 11, and so forth, with 93.Ql Z 94representing 35.) 95.Pp 96If 97.Fa endptr 98is non nil, 99.Fn strtol 100stores the address of the first invalid character in 101.Fa *endptr . 102If there were no digits at all, however, 103.Fn strtol 104stores the original value of 105.Fa nptr 106in 107.Fa *endptr . 108(Thus, if 109.Fa *nptr 110is not 111.Ql \e0 112but 113.Fa **endptr 114is 115.Ql \e0 116on return, the entire string was valid.) 117.Sh RETURN VALUES 118The 119.Fn strtol 120function 121returns the result of the conversion, 122unless the value would underflow or overflow. 123If an underflow occurs, 124.Fn strtol 125returns 126.Dv LONG_MIN . 127If an overflow occurs, 128.Fn strtol 129returns 130.Dv LONG_MAX . 131In both cases, 132.Va errno 133is set to 134.Er ERANGE . 135.Sh ERRORS 136.Bl -tag -width [ERANGE] 137.It Bq Er ERANGE 138The given string was out of range; the value converted has been clamped. 139.El 140.Sh SEE ALSO 141.Xr atof 3 , 142.Xr atoi 3 , 143.Xr atol 3 , 144.Xr strtod 3 , 145.Xr strtoul 3 146.Sh STANDARDS 147The 148.Fn strtol 149function 150conforms to 151.St -ansiC . 152.Sh BUGS 153Ignores the current locale. 154