Administrace komentářů

Ahoj,

posledne jsem tu resil implementaci pipe v C:

http://www.abclinuxu.cz/poradna/programovani/show/373050

Potreboval bych tutez funkcionalitu implementovat s

mkfifo()

.

Cili aby mi to po spusteni programu s arametry a delimiterem:

./pipe ls -la @ grep -v .c

provedlo to stejne jakov shellu.

Postup bude pravdepodobne stejny, budou tam dva openy asi. Zatim jsem se dostal k hrubemu kodu nize. Nefunguje mi tam ale otevreni fopen():

fopen: No such file or directory

Celkem tapu jak ty prikazy poskladat, aby mi to fungovalo. Budu rad za jakoukoliv radu. Diky.

Dosavadni kod (puvodne to byl kod pro nepojmenovanou rouru, stare radky jsou vykomentovane):

int main(int argc,char *argv[]) {

	if (argc < 2) {
	
		printf("Programme must be run with with arguments and using pipe shell symbol as a delimiter!\n"
			"For example: ./pipe ls -la @ grep -v .c\n");
		exit(1);
	}
        
        int count, fw, fr;
        char command1[50];
        char command2[50];
        char arguments1[50];
        char arguments2[50];
        
        strcpy(command1, argv[1]);
        strcpy(arguments1, " ");
        strcpy(arguments2, " ");

        count = 2;
        
        for (; count < argc; count++) {
                        
            if (strcmp(argv[count], "@") == 0) {
                
                break;
            }
            
            strcat(arguments1, argv[count]);
            strcat(arguments1, " ");
        }
        
        arguments1[strlen(arguments1)-1] = '\0';  //removing ending space       
        strcat(command1, arguments1);      
        strcpy(command2, argv[count+1]);
        count += 2;


        for ( ; count < argc; count++) {
            
            strcat(arguments2, argv[count]);
            strcat(arguments2, " ");
        }
        
        arguments1[strlen(arguments2)-1] = '\0'; 
        strcat(command2, arguments2);
                
        mkfifo(FIFO_FILE, S_IFIFO|0666);

	pid_t pid = fork();
	
	if (pid == -1)  
	   return -1;  

	if (pid == 0) {
	  
	   //close(fifo); //close write to pipe, in child
	   //dup2(fifo, STDIN_FILENO); // Replace stdin with the read end of the pipe
	   //close(fifo); // Don't need another copy of the pipe read end hanging about

            if(fr = fopen(FIFO_FILE, "r") == NULL) {
                perror("fopen");
                exit(1);
            }
            dup2(fr, STDIN_FILENO);
            close(fr);
            
            system(command2); 
	}

	else {
	
	   //close(fifo); //close read from pipe, in parent
	   //dup2(fifo, STDOUT_FILENO); // Replace stdout with the write end of the pipe
	   //close(fifo); // Don't need another copy of the pipe write end hanging about;
            

            if(fw = fopen(FIFO_FILE, "w") == NULL) {
                perror("fopen");
                exit(1);
            }
            dup2(fw, STDOUT_FILENO);
            close(fw);
            system(command1); 
	}  
	
	return EXIT_SUCCESS;
}