🚀 go-pugleaf

In es.comp.os.linux.programacion Claudio S. <claudio@ningun.sitio.es> wrote:

:> 
:> Usando pipe() genero un par de descriptores (in[0] e in[1]), de
:> forma que yo leo de in[0] lo que el programa escribe en in[1].
:> 
:> De igual forma, con otro pipe() hago out[0] y out[1] de forma que
:> lo que yo escribo en out[1] lo lee el programa en out[0].

	si te entendido bien, lo que necesitas es el comando "69" :

-8<--- 69.c ---------------------------------------------------------------
/*
 * (c) SPDsoft 1994
 * 24 julio 1994
 * 
 * Launch two processes:
 *				output cmd[0] -> input cmd[1]
 *				input cmd[0] <- output cmd[1]
 */

#include <stdio.h>
#include <errno.h>
#include <sys/types.h>

main(int argc, char **argv)
{
	pid_t		pid;
	int		pipefd[2][2];
	int		i;
	char		**cmd[2];
	extern int	errno;
	char		strerr[256];

	cmd[0] = &argv[1];
	cmd[1] = NULL;

	for(i=1; ( i<argc)&&(strcmp(argv[i],";")!=0); i ++)
	;

	if ( i < argc -1 )
	{
		argv[i] = (char*) 0;
		cmd[1] = &argv[i+1];
	}


	if  (( argc < 4 ) || ( cmd[1] == NULL ))
	{
		sprintf(strerr,
		"%s: SPDsoft 1994: Sixty-nine two processes\n"
		"Usage: %s cmd1 [args] ; cmd2 [args]\n",
		argv[0] , argv[0]);

		write(2, strerr, strlen(strerr));
		exit(-1);
	}

	pipe (pipefd[0]);
	pipe (pipefd[1]);


	if ((pid = fork()) == (pid_t)0)
	{
		close(0);
		close(1);

		dup (pipefd[1][0]);
		dup (pipefd[0][1]);
		close (pipefd[0][0]);
		close (pipefd[1][1]);

		execvp(*cmd[0], cmd[0]);
		sprintf(strerr,"%s: Can't execvp %s (%s)\n",
		argv[0], *cmd[0], strerror(errno));
		write(2, strerr, strlen(strerr));
		exit(errno);
	}
	else if (pid > (pid_t)0)
	{
		close(0);
		close(1);

		dup (pipefd[0][0]);
		dup (pipefd[1][1]);
		close (pipefd[1][0]);
		close (pipefd[0][1]);

		execvp(*cmd[1], cmd[1]);
		sprintf(strerr,"%s: Can't execvp %s (%s)\n",
		argv[0], *cmd[1], strerror(errno));
		write(2, strerr, strlen(strerr));
		exit(errno);
	}
	else
		perror("fork");
		exit(errno);
}
-8<------------------------------------------------------------------------


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