plan9port/man/man3/encode.3
Russ Cox 977b25a76a tmac: introduce real manual reference macro instead of overloading IR
The overloading of IR emits magic \X'...' sequences that turn into HTML manual links.
But not all such IR invocations should be manual links;
those had to be written to avoid the IR macro before.
Worse, the \X'...' ending the IR causes troff to emit only a single space after a period.

Defining a new IM macro for manual references fixes both problems.

Fixes #441.
2020-08-13 23:43:43 -04:00

85 lines
1.5 KiB
Groff

.TH ENCODE 3
.SH NAME
dec64, enc64, dec32, enc32, dec16, enc16, encodefmt \- encoding byte arrays as strings
.SH SYNOPSIS
.B #include <u.h>
.br
.B #include <libc.h>
.PP
.B
int dec64(uchar *out, int lim, char *in, int n)
.PP
.B
int enc64(char *out, int lim, uchar *in, int n)
.PP
.B
int dec32(uchar *out, int lim, char *in, int n)
.PP
.B
int enc32(char *out, int lim, uchar *in, int n)
.PP
.B
int dec16(uchar *out, int lim, char *in, int n)
.PP
.B
int enc16(char *out, int lim, uchar *in, int n)
.PP
.B
int encodefmt(Fmt*)
.SH DESCRIPTION
.PP
.IR Enc16 ,
.I enc32
and
.I enc64
create null terminated strings. They return the size of the
encoded string (without the null) or -1 if the encoding fails.
The encoding fails if
.IR lim ,
the length of the output buffer, is too small.
.PP
.IR Dec16 ,
.I dec32
and
.I dec64
return the number of bytes decoded or -1 if the decoding fails.
The decoding fails if the output buffer is not large enough or,
for base 32, if the input buffer length is not a multiple
of 8.
.PP
.I Encodefmt
can be used with
.IM fmtinstall (3)
and
.IM print (3)
to print encoded representations of byte arrays.
The verbs are
.TP
.B H
base 16 (i.e. hexadecimal). The default encoding is
in upper case. The
.B l
flag forces lower case.
.TP
.B <
base 32
.TP
.B [
base 64 (same as MIME)
.PD
.PP
The length of the array is specified as
.IR f2 .
For example, to display a 15 byte array as hex:
.EX
char x[15];
fmtinstall('H', encodefmt);
print("%.*H\\n", sizeof x, x);
.EE
.SH SOURCE
.B \*9/src/lib9/u32.c
.br
.B \*9/src/lib9/u64.c