$home/manuals/plan9_4th/2/encode

ENCODE(2)                     System Calls Manual                    ENCODE(2)



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NAME
       dec64, enc64, dec32, enc32, dec16, enc16, encodefmt - encoding byte ar‐
       rays 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



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