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.TH ENCODE 2

.EQ

delim $$

.EN

.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

.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.

They require

$2 n + 1$, ${ 8 n + 4 } over 5 + 1$ and

$4 { { n + 2 } over 3 } + 1$ bytes,

respectively.

.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

.IR fmtinstall (2)

and

.IR print (2)

to print encoded representations of byte arrays.

The verbs are

.TP 3

.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:

.IP

.EX

char x[15];

fmtinstall('H', encodefmt);

print("%.*H\\n", sizeof x, x);

.EE

.SH SOURCE

.B /sys/src/libc/port/u[136][246].c