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a64l, l64a — convert between a 32-bit integer and a radix-64 ASCII string
long a64l(const char * s);
char *l64a(long value);
These functions maintain numbers stored in radix-64 ASCII characters. This is a
notation by which 32-bit integers can be represented by up to six characters;
each character represents a digit in radix-64 notation. If the type
contains more than 32 bits, only the low-order 32 bits shall be
used for these operations.
The characters used to represent digits are '.'
(dot) for 0, '/'
for 1, '0'
for [2,11], 'A'
for [12,37], and 'a'
() function shall take a pointer to a radix-64 representation, in
which the first digit is the least significant, and return the corresponding
value. If the string pointed to by s
contains more than six
() shall use the first six. If the first six characters
of the string contain a null terminator, a64l
() shall use only
characters preceding the null terminator. The a64l
() function shall
scan the character string from left to right with the least significant digit
on the left, decoding each character as a 6-bit radix-64 number. If the type
contains more than 32 bits, the resulting value is sign-extended.
The behavior of a64l
() is unspecified if s
is a null pointer or
the string pointed to by s
was not generated by a previous call to
() function shall take a long
argument and return a
pointer to the corresponding radix-64 representation. The behavior of
() is unspecified if value
The value returned by l64a
() may be a pointer into a static buffer.
Subsequent calls to l64a
() may overwrite the buffer.
() function need not be thread-safe.
Upon successful completion, a64l
() shall return the long
resulting from conversion of the input string. If a string pointed to by
is an empty string, a64l
() shall return 0L.
() function shall return a pointer to the radix-64
representation. If value
is 0L, l64a
() shall return a pointer to
an empty string.
No errors are defined.
The following sections are informative.
If the type long
contains more than 32 bits, the result of
)) is x
in the low-order 32 bits.
This is not the same encoding as used by either encoding variant of the
The Base Definitions volume of POSIX.1‐2008,
The Shell and Utilities volume of POSIX.1‐2008, uuencode
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
7, Copyright (C) 2013 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013
Technical Corrigendum 1 applied.) In the event of any discrepancy between this
version and the original IEEE and The Open Group Standard, the original IEEE
and The Open Group Standard is the referee document. The original Standard can
be obtained online at http://www.unix.org/online.html .
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