Due in 5 hours, Unix linux homework

my name is BAO TRUONG btw

in case you ahve to put the name

in the assignment

first name Bao, last name Truong

TwoPipesTwoChildren.cpp:

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/types.h>

#include <sys/stat.h>

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

int status;

char *cat_args[] = {"ls", "-ltr", NULL};

char *grep_args[] = {"grep", "3340", NULL};

char *wc_args[] = {"wc", "-l", NULL};

// create two pipea to send the output of "ls" process to "grep" process and to "wc" process

int pipe_A[2];

int pipe_B[2];

pipe(pipe_A);

pipe(pipe_B);

pid_t pid_A, pid_B;

//first child

if( !(pid_A = fork()) ) {

close(pipe_A[0]);

dup2(pipe_A[1], 1); /* redirect standard output to pipe_A write end */

close(pipe_A[1]);

execvp(*cat_args, cat_args);

exit(0);

}

//second child

else if( !(pid_B = fork()) ) {

close(pipe_A[1]);

dup2(pipe_A[0], 0); /* redirect standard input to pipe_A read end */

close(pipe_A[0]);

close(pipe_B[0]);

dup2(pipe_B[1], 1); /* redirect standard output to pipe_B write end */

close(pipe_B[1]);

execvp(*grep_args, grep_args);

}

//parent

else {

close(pipe_A[1]);

close(pipe_A[0]);

close(pipe_B[1]);

dup2(pipe_B[0], 0); /* redirect standard input to pipe_B read end */

close(pipe_B[0]);

execvp(*wc_args, wc_args);

}

close(pipe_B[1]);

close(pipe_B[0]);

return(0);

}

TwoPipesThreeChildren.cpp: #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> int main(int argc, char **argv) { int status; char *cat_args[] = {"ls", "-ltr", NULL}; char *grep_args[] = {"grep", "3340", NULL}; char *wc_args[] = {"wc", "-l", NULL}; // create two pipea to send the output of "ls" process to "grep" process and to "wc" process int pipe_A[2]; int pipe_B[2];

pipe(pipe_A);

pid_t pid_A, pid_B, pid_C; //first child if( !(pid_A = fork()) ) { close(pipe_A[0]); dup2(pipe_A[1], 1); /* redirect standard output to pipe_A write end */ close(pipe_A[1]); execvp(*cat_args, cat_args); exit(0); } pipe(pipe_B); //second child if( !(pid_B = fork()) ) { close(pipe_A[1]); dup2(pipe_A[0], 0); /* redirect standard input to pipe_A read end */ close(pipe_A[0]); close(pipe_B[0]); dup2(pipe_B[1], 1); /* redirect standard output to pipe_B write end */ close(pipe_B[1]); execvp(*grep_args, grep_args); } close(pipe_A[1]); close(pipe_A[0]); //third child if( !(pid_C = fork()) ) { close(pipe_B[1]); dup2(pipe_B[0], 0); /* redirect standard input to pipe_B read end */ close(pipe_B[0]); execvp(*wc_args, wc_args); } close(pipe_B[1]); close(pipe_B[0]); return(0); }