1.\" $OpenBSD: a64l.3,v 1.11 2010/04/01 17:06:55 jmc Exp $ 2.\" 3.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com> 4.\" 5.\" Permission to use, copy, modify, and distribute this software for any 6.\" purpose with or without fee is hereby granted, provided that the above 7.\" copyright notice and this permission notice appear in all copies. 8.\" 9.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16.\" 17.Dd $Mdocdate: April 1 2010 $ 18.Dt A64L 3 19.Os 20.Sh NAME 21.Nm a64l , 22.Nm l64a 23.Nd convert between 32-bit integer and radix-64 ASCII string 24.Sh SYNOPSIS 25.Fd #include <stdlib.h> 26.Ft long 27.Fn a64l "const char *s" 28.Ft char * 29.Fn l64a "long l" 30.Sh DESCRIPTION 31The 32.Fn a64l 33and 34.Fn l64a 35functions are used to maintain numbers stored in radix-64 36.Tn ASCII 37characters. 38This is a notation by which 32-bit integers 39can be represented by up to six characters; each character represents a 40.Dq digit 41in a radix-64 notation. 42.Pp 43The characters used to represent digits are 44.Ql \&. 45for 0, 46.Ql / 47for 1, 48.Ql 0 49through 50.Ql 9 51for 2-11, 52.Ql A 53through 54.Ql Z 55for 12-37, and 56.Ql a 57through 58.Ql z 59for 38-63. 60.Pp 61The 62.Fn a64l 63function takes a pointer to a NUL-terminated radix-64 representation 64and returns a corresponding 32-bit value. 65If the string pointed to by 66.Fa s 67contains more than six characters, 68.Fn a64l 69will use the first six. 70.Fn a64l 71scans the character string from left to right, decoding 72each character as a 6-bit radix-64 number. 73If a long integer is 74larger than 32 bits, the return value will be sign-extended. 75.Pp 76.Fn l64a 77takes a long integer argument 78.Fa l 79and returns a pointer to the corresponding radix-64 representation. 80.Sh RETURN VALUES 81On success, 82.Fn a64l 83returns a 32-bit representation of 84.Fa s . 85If 86.Fa s 87is a null pointer or if it contains digits other than those described above, 88.Fn a64l 89returns \-1 and sets the global variable 90.Va errno 91to 92.Er EINVAL . 93.Pp 94On success, 95.Fn l64a 96returns a pointer to a string containing the radix-64 representation of 97.Fa l . 98If 99.Fa l 100is 0, 101.Fn l64a 102returns a pointer to the empty string. 103If 104.Fa l 105is negative, 106.Fn l64a 107returns a null pointer and sets the global variable 108.Va errno 109to 110.Er EINVAL . 111.Sh STANDARDS 112The 113.Fn a64l 114and 115.Fn l64a 116functions conform to 117.St -xpg4.2 . 118.Sh CAVEATS 119The value returned by 120.Fn l64a 121is a pointer into a static buffer, the contents of which 122will be overwritten by subsequent calls. 123.Pp 124The value returned by 125.Fn a64l 126may be incorrect if the value is too large; for that reason, only strings 127that resulted from a call to 128.Fn l64a 129should be used to call 130.Fn a64l . 131.Pp 132If a long integer is larger than 32 bits, only the low-order 13332 bits are used. 134