1.\" Copyright (c) 2005 Tom Rhodes 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" Portions of this text are reprinted and reproduced in electronic form 26.\" from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- 27.\" Portable Operating System Interface (POSIX), The Open Group Base 28.\" Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of 29.\" Electrical and Electronics Engineers, Inc and The Open Group. In the 30.\" event of any discrepancy between this version and the original IEEE and 31.\" The Open Group Standard, the original IEEE and The Open Group Standard is 32.\" the referee document. The original Standard can be obtained online at 33.\" http://www.opengroup.org/unix/online.html. 34.\" 35.\" $FreeBSD$ 36.\" 37.Dd November 20, 2005 38.Dt A64L 3 39.Os 40.Sh NAME 41.Nm a64l , 42.Nm l64a , 43.Nm l64a_r 44.Nd "convert between a long integer and a base-64 ASCII string" 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.In stdlib.h 49.Ft long 50.Fn a64l "const char *s" 51.Ft char * 52.Fn l64a "long int l" 53.Ft int 54.Fn l64a_r "long int l" "char *buffer" "int buflen" 55.Sh DESCRIPTION 56These functions are used to maintain numbers stored in radix-64 57.Tn ASCII 58characters. 59This is a notation by which 32-bit integers can be represented by 60up to six characters; each character represents a digit in 61radix-64 notation. 62If the type long contains more than 32 bits, only the low-order 6332 bits are used for these operations. 64.Pp 65The characters used to represent 66.Dq digits 67are 68.Ql .\& 69for 0, 70.Ql / 71for 1, 72.Ql 0 73- 74.Ql 9 75for 2 - 11, 76.Ql A 77- 78.Ql Z 79for 12 - 37, and 80.Ql a 81- 82.Ql z 83for 38 - 63. 84.Pp 85The 86.Fn a64l 87function takes a pointer to a radix-64 representation, in which the first 88digit is the least significant, and returns a corresponding 89.Vt long 90value. 91If the string pointed to by 92.Fa s 93contains more than six characters, 94.Fn a64l 95uses the first six. 96If the first six characters of the string contain a null terminator, 97.Fn a64l 98uses only characters preceding the null terminator. 99The 100.Fn a64l 101function scans the character string from left to right with the least 102significant digit on the left, decoding each character as a 6-bit 103radix-64 number. 104If the type long contains more than 32 bits, the resulting value is 105sign-extended. 106The behavior of 107.Fn a64l 108is unspecified if 109.Fa s 110is a null pointer or the string pointed to by 111.Fa s 112was not generated by a previous call to 113.Fn l64a . 114.Pp 115The 116.Fn l64a 117function takes a 118.Vt long 119argument and returns a pointer to the corresponding 120radix-64 representation. 121The behavior of 122.Fn l64a 123is unspecified if value is negative. 124.Pp 125The value returned by 126.Fn l64a 127is a pointer into a static buffer. 128Subsequent calls to 129.Fn l64a 130may overwrite the buffer. 131.Pp 132The 133.Fn l64a_r 134function performs a conversion identical to that of 135.Fn l64a 136and stores the resulting representation in the memory area pointed to by 137.Fa buffer , 138consuming at most 139.Fa buflen 140characters including the terminating 141.Dv NUL 142character. 143.Sh RETURN VALUES 144On successful completion, 145.Fn a64l 146returns the 147.Vt long 148value resulting from conversion of the input string. 149If a string pointed to by 150.Fa s 151is an empty string, 152.Fn a64l 153returns 0. 154.Pp 155The 156.Fn l64a 157function returns a pointer to the radix-64 representation. 158If value is 0, 159.Fn l64a 160returns a pointer to an empty string. 161.Sh SEE ALSO 162.Xr strtoul 3 163.Sh HISTORY 164The 165.Fn a64l , 166.Fn l64a , 167and 168.Fn l64a_r 169functions are derived from 170.Nx 171with modifications. 172They appeared in 173.Fx 6.1 . 174.Sh AUTHORS 175The 176.Fn a64l , 177.Fn l64a , 178and 179.Fn l64a_r 180functions 181were added to 182.Fx 183by 184.An Tom Rhodes Aq Mt trhodes@FreeBSD.org . 185Almost all of this manual page came from the 186.Tn POSIX 187standard. 188