76 lines
1.9 KiB
C
76 lines
1.9 KiB
C
/*
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* ipcpipe2.c - Pipes are unidirectional and require
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* two pipes to send data in two directions
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*/
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#include <sys/types.h> // needed for pid_t
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#include <sys/wait.h> // needed for wait system call
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#include <unistd.h> // needed for fork, read, write, close system calls
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#include <stdlib.h> // needed for exit
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#include <stdio.h> // needed for printf, perror
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int main()
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{
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/* Create pipes */
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int pipe_to_child[2];
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if (pipe(pipe_to_child) == -1) {
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printf("PIPE FAILURE\n");
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exit(EXIT_FAILURE);
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}
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int pipe_from_child[2];
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if (pipe(pipe_from_child) == -1) {
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printf("PIPE FAILURE\n");
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exit(EXIT_FAILURE);
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}
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pid_t pid = fork(); // fork into 2 processes
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if (pid == -1) // error
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{
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perror("fork");
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exit(EXIT_FAILURE);
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}
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else if (pid == 0) //
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{
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/* Close unused pipe ends */
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close(pipe_to_child[1]);
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close(pipe_from_child[0]);
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/* Write to parent */
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write(pipe_from_child[1], "CHELLO", 6);
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close(pipe_from_child[1]);
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/* Read from parent */
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char data[32];
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read(pipe_to_child[0], data, sizeof(data));
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printf("Child received %s from parent\n", data);
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/* Close pipe */
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close(pipe_to_child[0]);
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return 0; // Return success
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}
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else // parent
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{
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/* Close unused pipe ends */
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close(pipe_to_child[0]);
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close(pipe_from_child[1]);
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/* Write to child */
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write(pipe_to_child[1], "PHELLO", 6);
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close(pipe_to_child[1]);
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/* Read from child */
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char data[32];
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read(pipe_from_child[0], data, sizeof(data));
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printf("Parent recieved %s from child\n", data);
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/* Close pipe */
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close(pipe_from_child[0]);
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/* Wait for child */
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wait(0);
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}
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return 0; // Return success
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}
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