.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com> .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. The name of the author may not be used to endorse or promote products .\" derived from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, .\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY .\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL .\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, .\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, .\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; .\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, .\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR .\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF .\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" .\" $OpenBSD: a64l.3,v 1.5 2000/04/20 13:50:01 aaron Exp $ .\" .Dd August 17, 1997 .Dt A64L 3 .Os .Sh NAME .Nm a64l , .Nm l64a .Nd convert between 32-bit integer and radix-64 ASCII string .Sh SYNOPSIS .Fd #include <stdlib.h> .Ft long .Fn a64l "const char *s" .Ft char * .Fn l64a "long value" .Sh DESCRIPTION The .Fn a64l and .Fn l64a functions are used to maintain numbers stored in radix-64 .Tn ASCII characters. This is a notation by which 32-bit integers can be represented by up to six characters; each character represents a .Dq digit in a radix-64 notation. .Pp The characters used to represent digits are .Ql \&. for 0, .Ql / for 1, .Ql 0 through .Ql 9 for 2-11, .Ql A through .Ql Z for 12-37, and .Ql a through .Ql z for 38-63. .Pp The .Fn a64l function takes a pointer to a null-terminated radix-64 representation and returns a corresponding 32-bit value. If the string pointed to by .Fa s contains more than six characters, .Fn a64l will use the first six. .Fn a64l scans the character string from left to right, decoding each character as a 6-bit radix-64 number. If a long integer is larger than 32 bits, the return value will be sign-extended. .Pp .Fn l64a takes a long integer argument .Fa value and returns a pointer to the corresponding radix-64 representation. .Sh RETURN VALUES On success, .Fn a64l returns a 32-bit representation of .Fa s . If .Fa s is a null pointer or if it contains digits other than those described above. .Fn a64l returns \-1 and sets the global variable .Va errno to .Er EINVAL . .Pp On success, .Fn l64a returns a pointer to a string containing the radix-64 representation of .Fa value . If .Fa value is 0, .Fn l64a returns a pointer to the empty string. If .Fa value is negative, .Fn l64a returns a null pointer and sets the global variable .Va errno to .Er EINVAL . .Sh WARNINGS The value returned by .Fn l64a is a pointer into a static buffer, the contents of which will be overwritten by subsequent calls. .Pp The value returned by .Fn a64l may be incorrect if the value is too large; for that reason, only strings that resulted from a call to .Fn l64a should be used to call .Fn a64l . .Pp If a long integer is larger than 32 bits, only the low-order 32 bits are used. .Sh STANDARDS The .Fn a64l and .Fn l64a functions conform to .St -xpg4.2 .