example/posix/pipes-basic_usage.c

Shows basic usage of anonymous pipes

#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>

int main(void)
{
    // the pair of file descriptors representing
    // both ends of the pipe
    int pipe_fds[2];

    // the end open for reading is at index 0
    const int read_end = 0;
    // the end open for writing is at index 1
    const int write_end = 1;

    // try to create a new anonymous pipe
    if(pipe(pipe_fds) < 0)
    {
        // complain on error and exit
        perror("Error creating pipe");
        return 1;
    }

    // write a test string into the end of the pipe
    // that is open for writing
    const char* input = "This is a test input string";
    write(pipe_fds[write_end], input, strlen(input)+1);

    // read input into a buffer from the end of the pipe
    // that is open for reading
    char buffer[256];
    read(pipe_fds[read_end], buffer, sizeof(buffer)/sizeof(buffer[0]));

    // print the read string
    printf("Read '%s' from the pipe\n", buffer);

    // input and the contents of the buffer should be the same
    assert(strcmp(input, buffer) == 0);
    return 0;
}