ENCODE(2) ENCODE(2)
delim $$
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
$2n+1$, $(8n+4)/5+1$ and $(n+2)/3)*4 + 1$ bytes, respec-
tively.
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];
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fmtinstall('H', encodefmt);
print("%.*H\n", sizeof x, x);
SOURCE
/sys/src/libc/port/u16.c
/sys/src/libc/port/u32.c
/sys/src/libc/port/u64.c
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