a64l.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 70 行

.\" SCCSID: @(#)a64l.3	8.1	9/11/90
.TH a64l 3
.SH Name
a64l, l64a \- convert long integer and base-64 ASCII string
.SH Syntax
.B long a64l (s)
.br
.B char \(**s;
.PP
.B char \(**l64a (l)
.br
.B long l;
.SH Description
.NXR "a64l subroutine"
.NXR "l64a subroutine"
.NXR "ASCII string" "converting long integer to"
These functions are used to maintain numbers stored in base-64
ASCII characters.
This is a notation by which
long integers can be represented by up to six characters; each character
represents a ``digit'' in a radix-64 notation.
.PP
The characters used to represent ``digits''
are
.B .
for 0,
.B /
for 1,
.B 0
through
.B 9
for 2\-11,
.B A
through
.B Z
for 12\-37, and
.B a
through
.B z
for 38\-63.
.PP
The
.PN a64l
subroutine
takes a pointer to a null-terminated base-64 representation and returns
a corresponding
.B long
value.
If the string pointed to by
.I s\^
contains more than six characters,
.PN a64l
will use the first six.
.PP
The
.PN l64a
subroutine takes a
.B long
argument and returns a pointer
to the corresponding base-64 representation.
If the argument is 0,
.PN l64a
returns a pointer to a
null string.
.SH Restrictions
The value returned by
.PN l64a
is a pointer into a static buffer, the contents of which are
overwritten by each call.