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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <gio.h>
# GTR_DISCONNECT -- Disconnect from a kernel subprocess. To achieve an orderly
# shutdown we process any outstanding XMIT or XFER requests, then transmit an
# end of file (zero length record) to the kernel task when it reads from the
# graphics stream. The kernel should then shutdown and eventually we will
# receive "bye" from the process. We then call PRCLOSE to shutdown the
# process for good. Note: we do not expect anything but an XFER (read) request
# on the graphics stream, but it seems prudent to do something reasonable if
# some other request is received.
procedure gtr_disconnect (pid, in, out, stream)
int pid # process id of subprocess
int in, out # command i/o streams of the subprocess
int stream # graphics stream used by kernel
pointer sp, sp2, lbuf, buf
int pseudofile, nchars, junk
bool streq()
int getline(), read(), strncmp(), psio_isxmit(), prclose(), pr_findproc()
errchk getline, prclose, read, write
begin
call smark (sp)
call salloc (lbuf, SZ_LINE, TY_CHAR)
while (getline (in, Memc[lbuf]) != EOF) {
if (streq (Memc[lbuf], "bye\n") ||
strncmp (Memc[lbuf], "ERROR", 5) == 0) {
junk = prclose (pid)
break
} else if (Memc[lbuf] == '!') {
# OS escape.
call proscmd (pr_findproc(pid), Memc[lbuf+1])
} else {
call smark (sp2)
switch (psio_isxmit (Memc[lbuf], pseudofile, nchars)) {
case XMIT:
call salloc (buf, nchars, TY_CHAR)
nchars = read (in, Memc[buf], nchars)
if (nchars > 0)
if (pseudofile == STDOUT || pseudofile == STDERR)
call write (pseudofile, Memc[buf], nchars)
case XFER:
call salloc (buf, nchars, TY_CHAR)
if (pseudofile == STDIN)
nchars = read (pseudofile, Memc[buf], nchars)
else
nchars = 0 # this is the EOF
call psio_xfer (out, Memc[buf], nchars)
}
call sfree (sp2)
}
}
call sfree (sp)
end
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