9srv Manual Collection/plan9/encode(2) 9srv Manual Collection/plan9/encode(2)
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NAME
dec64, enc64, dec32, enc32, dec16, enc16, encodefmt - encoding byte arrays as strings

SYNOPSIS
#include <u.h>
#include <libc.h>

int dec64(uchar *out, int lim, char *in, int n)

int enc64(char *out, int lim, uchar *in, int n)

int dec32(uchar *out, int lim, char *in, int n)

int enc32(char *out, int lim, uchar *in, int n)

int dec16(uchar *out, int lim, char *in, int n)

int enc16(char *out, int lim, uchar *in, int n)

int encodefmt(Fmt*)

DESCRIPTION
Enc16, enc32 and 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 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.

Dec16, dec32 and 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.

Encodefmt can be used with fmtinstall(2) and print(2) to print encoded representations of byte arrays. The verbs are


H
base 16 (i.e. hexadecimal). The default encoding is in upper case. The l flag forces lower case.
<
base 32
[
base 64 (same as MIME)

The length of the array is specified as f2. For example, to display a 15 byte array as hex:

char x[15]; fmtinstall('H', encodefmt); print("%.*H\n", sizeof x, x);

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

9srv Manual Collection/plan9/encode(2) Rev:  Thu Mar 29 21:23:42 BST 2012