DataMuseum.dk

top - metrics - download

    Length: 3209 (0xc89)
    Types: TextFile
    Names: »portsrv.c«

└─⟦a0efdde77⟧ Bits:30001252 EUUGD11 Tape, 1987 Spring Conference Helsinki
    └─⟦this⟧ »EUUGD11/euug-87hel/sec1/jove/portsrv.c« 

TextFile

/************************************************************************
 * This program is Copyright (C) 1986 by Jonathan Payne.  JOVE is       *
 * provided to you without charge, and with no warranty.  You may give  *
 * away copies of JOVE, including sources, provided that this notice is *
 * included in all the files.                                           *
 ************************************************************************/

/* This is a server for jove sub processes.  It runs the command and
   signals jove when there is some output ready to send to jove. By the
   time we get here, out standard output goes to jove's process input. */

#include "tune.h"

#ifdef PIPEPROCS	/* the whole file! */

#include "jove.h"

#include <signal.h>
#include <sys/ioctl.h>
#ifdef BSD4_2
#   include <sys/wait.h>
#else
#   include <wait.h>
#endif

struct header {
	int	pid;
	int	nbytes;
	char	buf[512];
} header;

#define HEADSIZE	((sizeof header.pid) + sizeof (header.nbytes))

error(str)
char	*str;
{
	header.pid = getpid();
	header.nbytes = strlen(str);
	strcpy(header.buf, str);
	proc_write(&header, header.nbytes + 8);
	exit(-2);
}

int	ppid,
	InputFD,
	JovesInput;

p_inform()
{
	long	nbytes;

	ioctl(JovesInput, FIONREAD, (char *) &nbytes);
	if (nbytes > 0)
		kill(ppid, INPUT_SIG);
}

proc_write(ptr, n)
char	*ptr;
{
	long	nbytes;

	ioctl(1, FIONREAD, (char *) &nbytes);
	
	if (nbytes == 0)
		kill(ppid, INPUT_SIG);

	(void) write(1, ptr, n);
	alarm(1);
}

read_pipe()
{
	register int	n;
	
	(void) signal(SIGALRM, p_inform);

	while ((header.nbytes = read(InputFD, header.buf, sizeof header.buf)) > 0) {
		n = HEADSIZE + header.nbytes;
		proc_write(&header, n);
	}
}

/* ARGSUSED */
main(argc, argv)
char	*argv[];
{
	int	p[2];
	int	pid;

	if (pipe(p) == -1)
		error("Cannot pipe jove portsrv.\n");

	ppid = getppid();
	switch (pid = fork()) {
	case -1:
		error("portsrv: cannot fork.\n");

	case 0:
		/* We'll intercept childs output in p[0] */
		(void) dup2(p[1], 1);
		(void) dup2(p[1], 2);
		(void) close(p[0]);
		(void) close(p[1]);
			
		(void) setpgrp(getpid(), getpid());
		execv(argv[2], &argv[3]);
		_exit(-4);

	default:
		(void) close(0);
				/* Don't want this guy to read anything
				   jove sends to our soon to be created
				   child */

		JovesInput = atoi(argv[1]);
		(void) signal(SIGINT, SIG_IGN);
		(void) signal(SIGQUIT, SIG_IGN);
		(void) close(p[1]);

		/* Tell jove the pid of the real child as opposed to us. */
		header.pid = getpid();
		header.nbytes = sizeof (int);
		*(int *) header.buf = pid;
		(void) write(1, (char *) &header, sizeof pid + HEADSIZE);
		p_inform();	/* Inform jove */

		/* Read proc's output and send it to jove */
		InputFD = p[0];
		read_pipe();
		(void) close(p[0]);
		header.pid = getpid();
		header.nbytes = EOF;	/* Tell jove we are finished */
		(void) write(1, (char *) &header, HEADSIZE);
		p_inform();
		/* Try to exit like our child did ... */
		{
			union wait	w;

#ifndef VMUNIX
			while (wait2(&w.w_status, 0) != pid)
#else
			while (wait3(&w.w_status, 0, 0) != pid)
#endif
				;
			if (WIFEXITED(w))
				exit(w.w_retcode);
			else if (WIFSIGNALED(w))
				kill(getpid(), w.w_termsig);
		}
	}
}

#else PIPEPROCS
main()
{
}
#endif