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Top Forums Programming pipe() and poll() problem in C Post 302478766 by blackmamba21 on Wednesday 8th of December 2010 11:15:01 PM
Old 12-09-2010
thanks alot corona i change the fileno(stdout) to STD_FILENO and its working however i dont know how you manage to get tr to work i did the following change:
Code:
void executerCommande( char *commande[], int descripteur, char* option )
{
	int tubeEntree[2];
	int tubeSortie[2];
	int erreur;
	
	erreur = pipe( tubeEntree );
	if ( erreur == -1 )
	{
		printf( "Erreur lors de la création du tube %s\n", strerror( errno ) );
		exit( 1 );
	}
	erreur = pipe( tubeSortie );
	if ( erreur == -1 )
	{
		printf( "Erreur lors de la création du tube %s\n", strerror( errno ) );
		exit( 1 );
	}

	pid_t pid = fork();
	if ( pid == -1 )	// erreur
	{
		perror( "fork a échoué" );
		exit( 1 );
	}
	else if ( pid == 0 )	// child
	{
		erreur = close( tubeEntree[1] );		// closing writing end of tube from parent to child
		if ( erreur == -1 )
		{
			printf( "Erreur lors du close %s\n", strerror( errno ) );
			exit( 1 );
		}
		erreur = close( tubeSortie[0] );		// closing reading end of tube from child to parent
		if ( erreur == -1 )
		{
			printf( "Erreur lors du close %s\n", strerror( errno ) );
			exit( 1 );
		}
		erreur = dup2 ( tubeSortie[1], STDOUT_FILENO );		
		if ( erreur == -1 )	// redirecting stdout to writing end of tube from child to parent
		{
			printf( "Erreur lors du dup2 stdout: %s\n", strerror( errno ) );
			exit( 1 );
		}
		erreur = close( tubeSortie[1] );		// fermeture du doublon
		if ( erreur == -1 )
		{
			printf( "Erreur lors du close %s\n", strerror( errno ) );
			exit( 1 );
		}
		
		erreur = dup2( tubeEntree[0], STDIN_FILENO );		
		if ( erreur == -1 )	// redirecting stdin to reading end of tube from parent to child
		{
			printf( "Erreur lors du dup stdin: %s\n", strerror( errno ) );
			exit( 1 );
		}
		erreur = close( tubeEntree[0] );		// fermeture du doublon
		if ( erreur == -1 )
		{
			printf( "Erreur lors du close %s\n", strerror( errno ) );
			exit( 1 );
		}
		execvp( commande[0], commande );
	}
	else		// parent
	{
		int evenement;
		int commandeTerminee = 0;
		int length;
		char tampon [256];
		struct pollfd entrees[2];
		entrees[0].fd = 0;		// check stdin
		entrees[0].events = POLLIN | POLLPRI;		// surveiller pour des données normales ou prioritaires
		entrees[0].revents = 0;
		entrees[1].fd = tubeSortie[0];		// check reading end of tube from child to parent
		entrees[1].events = POLLIN | POLLPRI;		// surveiller pour des données normales ou prioritaires
		entrees[1].revents = 0;

		erreur = close( tubeEntree[0] );		// closing reading end of tube from parent to child
		if ( erreur == -1 )
		{
			printf( "Erreur lors du close %s\n", strerror( errno ) );
			exit( 1 );
		}
		erreur = close( tubeSortie[1] );		// closing writing end of tube from child to parent
		if ( erreur == -1 )
		{
			printf( "Erreur lors du close %s\n", strerror( errno ) );
			exit( 1 );
		}
		
		while ( commandeTerminee == 0 )
		{
			entrees[0].revents = 0;
			entrees[1].revents = 0;
			evenement = poll( entrees, 2, 0 );
			if ( evenement == -1 )
			{
				printf( "Erreur lors du poll %s\n", strerror( errno ) );
				exit( 1 );
			}
			if ( ( entrees[0].revents & POLLIN ) || ( entrees[0].revents & POLLPRI ) )
			{
				memset(tampon, '\0', 256);
				length = read( entrees[0].fd, tampon, 256 );
				if ( ( strcmp( option, "-i" ) == 0 ) || ( strcmp( option, "-io" ) == 0 ) )
				{
					erreur = write ( descripteur, tampon, strlen( tampon ) );
					if ( erreur == -1 )
					{
						printf( "Erreur lors de l'écriture sur le fichier %s\n", strerror( errno ) );
						exit( 1 );
					}
				}
				erreur = write ( tubeEntree[1], tampon, length );
				if ( erreur == -1 )
				{
					printf( "Erreur lors de l'écriture dans le tube d'entrée %s\n", strerror( errno ) );
					exit( 1 );
				}
			}
			if ( entrees[0].revents & POLLHUP )
			{
				commandeTerminee = 1;
			}
			if ( ( entrees[1].revents & POLLIN ) || ( entrees[1].revents & POLLPRI ) )
			{
				do {
					memset(tampon, '\0', 256);
					length = read( entrees[1].fd, tampon, 256 );
					if ( erreur == -1 )	
					{
						printf( "Erreur lors de la lecture du tube de sortie %s\n", strerror ( errno ) );
						exit( 1 );
					}
					if ( ( strcmp( option, "-o" ) == 0 ) || ( strcmp( option, "-io" ) == 0 ) )
					{
						erreur = write( descripteur, tampon, strlen( tampon ) );
						if ( erreur == -1 )	
						{
							printf( "Erreur lors de l'écriture sur le fichier %s\n", strerror ( errno ) );
							exit( 1 );
						}
					}
					printf( "%s", tampon );
				} while (erreur != 0);
			}
			if ( entrees[1].revents & POLLHUP )
			{
				commandeTerminee = 1;
			}
		}	
		pid = wait( NULL );
	}
}

 

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