You can redirect the output of type and emit and all the
words that use them (all output words that don’t have an explicit
target file) to an arbitrary file with the outfile-execute,
used like this:
: some-warning ( n -- )
cr ." warning# " . ;
: print-some-warning ( n -- )
['] some-warning stderr outfile-execute ;
After some-warning is executed, the original output direction
is restored; this construct is safe against exceptions. Similarly,
there is infile-execute for redirecting the input of key
and its users (any input word that does not take a file explicitly).
outfile-execute ( ... xt file-id – ... ) gforth-0.7 “outfile-execute”
execute xt with the output of type etc. redirected to
file-id.
outfile-id ( – file-id ) gforth-0.2 “outfile-id”
File-id is used by emit, type, and any output
word that does not take a file-id as input. By default
outfile-id produces the process’s stdout, unless
changed with outfile-execute.
infile-execute ( ... xt file-id – ... ) gforth-0.7 “infile-execute”
execute xt with the input of key etc. redirected to
file-id.
infile-id ( – file-id ) gforth-0.4 “infile-id”
File-id is used by key, ?key, and anything that
refers to the "user input device". By default infile-id
produces the process’s stdin, unless changed with
infile-execute.
If you do not want to redirect the input or output to a file, you can
also make use of the fact that key, emit and type
are deferred words (see Deferred Words). However, in that case
you have to worry about the restoration and the protection against
exceptions yourself; also, note that for redirecting the output in
this way, you have to redirect both emit and type.