[apple/libc.git] / stdlib / a64l.3

.\" 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 l"
.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 l
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 l .
If
.Fa l
is 0,
.Fn l64a
returns a pointer to the empty string.
If
.Fa l
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 .
Commit	Line	Data
5b2abdfb A	1	.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
	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	.\" 3. The name of the author may not be used to endorse or promote products
	13	.\" derived from this software without specific prior written permission.
	14	.\"
	15	.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
	16	.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
	17	.\" AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
	18	.\" THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	19	.\" EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	20	.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
	21	.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	22	.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	23	.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	24	.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	25	.\"
	26	.\" $OpenBSD: a64l.3,v 1.5 2000/04/20 13:50:01 aaron Exp $
	27	.\"
	28	.Dd August 17, 1997
	29	.Dt A64L 3
	30	.Os
	31	.Sh NAME
	32	.Nm a64l ,
	33	.Nm l64a
	34	.Nd convert between 32-bit integer and radix-64 ASCII string
	35	.Sh SYNOPSIS
	36	.Fd #include <stdlib.h>
	37	.Ft long
	38	.Fn a64l "const char *s"
	39	.Ft char *
	40	.Fn l64a "long l"
	41	.Sh DESCRIPTION
	42	The
	43	.Fn a64l
	44	and
	45	.Fn l64a
	46	functions are used to maintain numbers stored in radix-64
	47	.Tn ASCII
	48	characters.
	49	This is a notation by which 32-bit integers
	50	can be represented by up to six characters; each character represents a
	51	.Dq digit
	52	in a radix-64 notation.
	53	.Pp
	54	The characters used to represent digits are
	55	.Ql \&.
	56	for 0,
	57	.Ql /
	58	for 1,
	59	.Ql 0
	60	through
	61	.Ql 9
	62	for 2-11,
	63	.Ql A
	64	through
65	.Ql Z
66	for 12-37, and
67	.Ql a
68	through
69	.Ql z
70	for 38-63.
71	.Pp
72	The
73	.Fn a64l
74	function takes a pointer to a null-terminated radix-64 representation
75	and returns a corresponding 32-bit value.
76	If the string pointed to by
77	.Fa s
78	contains more than six characters,
79	.Fn a64l
80	will use the first six.
81	.Fn a64l
82	scans the character string from left to right, decoding
83	each character as a 6-bit radix-64 number.
84	If a long integer is
85	larger than 32 bits, the return value will be sign-extended.
86	.Pp
87	.Fn l64a
88	takes a long integer argument
89	.Fa l
90	and returns a pointer to the corresponding radix-64 representation.
91	.Sh RETURN VALUES
92	On success,
93	.Fn a64l
94	returns a 32-bit representation of
95	.Fa s .
96	If
97	.Fa s
98	is a null pointer or if it contains digits other than those described above.
99	.Fn a64l
100	returns \-1 and sets the global variable
101	.Va errno
102	to
103	.Er EINVAL .
104	.Pp
105	On success,
106	.Fn l64a
107	returns a pointer to a string containing the radix-64 representation of
108	.Fa l .
109	If
110	.Fa l
111	is 0,
112	.Fn l64a
113	returns a pointer to the empty string.
114	If
115	.Fa l
116	is negative,
117	.Fn l64a
118	returns a null pointer and sets the global variable
119	.Va errno
120	to
121	.Er EINVAL .
122	.Sh WARNINGS
123	The value returned by
124	.Fn l64a
125	is a pointer into a static buffer, the contents of which
126	will be overwritten by subsequent calls.
127	.Pp
128	The value returned by
129	.Fn a64l
130	may be incorrect if the value is too large; for that reason, only strings
131	that resulted from a call to
132	.Fn l64a
133	should be used to call
134	.Fn a64l .
135	.Pp
136	If a long integer is larger than 32 bits, only the low-order
137	32 bits are used.
138	.Sh STANDARDS
139	The
140	.Fn a64l
141	and
142	.Fn l64a
143	functions conform to
144	.St -xpg4.2 .
145