int char_buffer::do_image(int argc, char *argv[])
{
string s;
alterDeviceTo(argc, argv, 1);
argv += troff_arg; // skip all arguments up to troff/groff
argc -= troff_arg;
argv = addRegDef(argc, argv, "-rps4html=1");
argc++;
s = "-dwww-image-template=";
s += macroset_template;
s += '\0';
argv = addRegDef(argc, argv, s.contents());
argc++;
// override local settings and produce a page size letter postscript file
argv = addRegDef(argc, argv, "-P-pletter");
argc++;
#if defined(DEBUGGING)
# define IMAGE_DEBUG_STREAM OUTPUT_STREAM(troffFileName)
// slight security risk so only enabled if compiled with defined(DEBUGGING)
if (debug) {
int saved_stdout = save_and_redirect(STDOUT_FILENO, IMAGE_DEBUG_STREAM);
emit_troff_output(DEVICE_FORMAT(IMAGE_OUTPUT_FILTER));
set_redirection(STDOUT_FILENO, saved_stdout);
}
#endif
return run_output_filter(IMAGE_OUTPUT_FILTER, argc, argv);
}
int char_buffer::do_html(int argc, char *argv[])
{
string s;
alterDeviceTo(argc, argv, 0);
argv += troff_arg; // skip all arguments up to groff
argc -= troff_arg;
argv = addZ(argc, argv);
argc++;
s = "-dwww-image-template=";
s += macroset_template; // do not combine these statements,
// otherwise they will not work
s += '\0'; // the trailing `\0' is ignored
argv = addRegDef(argc, argv, s.contents());
argc++;
#if defined(DEBUGGING)
# define HTML_DEBUG_STREAM OUTPUT_STREAM(htmlFileName)
// slight security risk so only enabled if compiled with defined(DEBUGGING)
if (debug) {
int saved_stdout = save_and_redirect(STDOUT_FILENO, HTML_DEBUG_STREAM);
emit_troff_output(DEVICE_FORMAT(HTML_OUTPUT_FILTER));
set_redirection(STDOUT_FILENO, saved_stdout);
}
#endif
return run_output_filter(HTML_OUTPUT_FILTER, argc, argv);
}
int char_buffer::run_output_filter(int filter, int argc, char **argv)
{
int pipedes[2];
PID_T child_pid;
int status;
print_args(argc, argv);
if (pipe(pipedes) < 0)
sys_fatal("pipe");
#if MAY_FORK_CHILD_PROCESS
// This is the UNIX process model. To invoke our post-processor,
// we must `fork' the current process.
if ((child_pid = fork()) < 0)
sys_fatal("fork");
else if (child_pid == 0) {
// This is the child process fork. We redirect its `stdin' stream
// to read data emerging from our pipe. There is no point in saving,
// since we won't be able to restore later!
set_redirection(STDIN_FILENO, pipedes[0]);
// The parent process will be writing this data, so we should release
// the child's writeable handle on the pipe, since we have no use for it.
if (close(pipedes[1]) < 0)
sys_fatal("close");
// The IMAGE_OUTPUT_FILTER needs special output redirection...
if (filter == IMAGE_OUTPUT_FILTER) {
// with BOTH `stdout' AND `stderr' diverted to files.
set_redirection(STDOUT_FILENO, PS_OUTPUT_STREAM);
set_redirection(STDERR_FILENO, REGION_OUTPUT_STREAM);
}
// Now we are ready to launch the output filter.
execvp(argv[0], argv);
// If we get to here then the `exec...' request for the output filter
// failed. Diagnose it and bail out.
error("couldn't exec %1: %2", argv[0], strerror(errno), ((char *)0));
fflush(stderr); // just in case error() didn't
exit(1);
}
else {
// This is the parent process fork. We will be writing data to the
// filter pipeline, and the child will be reading it. We have no further
// use for our read handle on the pipe, and should close it.
if (close(pipedes[0]) < 0)
sys_fatal("close");
// Now we redirect the `stdout' stream to the inlet end of the pipe,
// and push out the appropiately formatted data to the filter.
pipedes[1] = save_and_redirect(STDOUT_FILENO, pipedes[1]);
emit_troff_output(DEVICE_FORMAT(filter));
// After emitting all the data we close our connection to the inlet
// end of the pipe so the child process will detect end of data.
set_redirection(STDOUT_FILENO, pipedes[1]);
// Finally, we must wait for the child process to complete.
if (WAIT(&status, child_pid, _WAIT_CHILD) != child_pid)
sys_fatal("wait");
}
#elif MAY_SPAWN_ASYNCHRONOUS_CHILD
// We do not have `fork', (or we prefer not to use it),
// but asynchronous processes are allowed, passing data through pipes.
// This should be ok for most Win32 systems and is preferred to `fork'
// for starting child processes under Cygwin.
// Before we start the post-processor we bind its inherited `stdin'
// stream to the readable end of our pipe, saving our own `stdin' stream
// in `pipedes[0]'.
pipedes[0] = save_and_redirect(STDIN_FILENO, pipedes[0]);
// for the Win32 model,
// we need special provision for saving BOTH `stdout' and `stderr'.
int saved_stdout = dup(STDOUT_FILENO);
int saved_stderr = STDERR_FILENO;
// The IMAGE_OUTPUT_FILTER needs special output redirection...
if (filter == IMAGE_OUTPUT_FILTER) {
// with BOTH `stdout' AND `stderr' diverted to files while saving a
// duplicate handle for `stderr'.
set_redirection(STDOUT_FILENO, PS_OUTPUT_STREAM);
saved_stderr = save_and_redirect(STDERR_FILENO, REGION_OUTPUT_STREAM);
}
// We then use an asynchronous spawn request to start the post-processor.
if ((child_pid = spawnvp(_P_NOWAIT, argv[0], argv)) < 0) {
// Should the spawn request fail we issue a diagnostic and bail out.
error("cannot spawn %1: %2", argv[0], strerror(errno), ((char *)0));
exit(1);
}
// Once the post-processor has been started we revert our `stdin'
// to its original saved source, which also closes the readable handle
// for the pipe.
set_redirection(STDIN_FILENO, pipedes[0]);
// if we redirected `stderr', for use by the image post-processor,
// then we also need to reinstate its original assignment.
if (filter == IMAGE_OUTPUT_FILTER)
set_redirection(STDERR_FILENO, saved_stderr);
// Now we redirect the `stdout' stream to the inlet end of the pipe,
// and push out the appropiately formatted data to the filter.
set_redirection(STDOUT_FILENO, pipedes[1]);
emit_troff_output(DEVICE_FORMAT(filter));
// After emitting all the data we close our connection to the inlet
// end of the pipe so the child process will detect end of data.
set_redirection(STDOUT_FILENO, saved_stdout);
// And finally, we must wait for the child process to complete.
if (WAIT(&status, child_pid, _WAIT_CHILD) != child_pid)
sys_fatal("wait");
#else /* can't do asynchronous pipes! */
// TODO: code to support an MS-DOS style process model
// should go here
#endif /* MAY_FORK_CHILD_PROCESS or MAY_SPAWN_ASYNCHRONOUS_CHILD */
return 0;
}
