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POClose file descriptor
 

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  1. POClose file descriptor
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    <p>I am trying to write so client-server program using 2 pipes, but when I run the following program (server.c): </p> <pre><code>#include &lt;stdlib.h&gt; #include &lt;stdio.h&gt; #include &lt;unistd.h&gt; #include &lt;sys/types.h&gt; #include &lt;sys/wait.h&gt; #include "err.h" #define BUF_SIZE 1024 char message[] = "Hello from your parent!\n"; char response[] = ""; int main (int argc, char *argv[]) { int fd1 [2]; int fd2 [2]; int buf_len; if (pipe (fd1) == -1) syserr("Error in pipe\n"); if (pipe (fd2) == -1) syserr("Error in pipe\n"); switch (fork ()) { case -1: syserr("Error in fork\n"); case 0: if (close (0) == -1) syserr("child, close (0)"); if (dup (fd1 [0]) != 0) syserr("child, dup (pipe_dsc [0])"); if (close (fd1 [0]) == -1) syserr("child, close (pipe_dsc [0])"); if (close (fd1 [1]) == -1) syserr("child, close (fd1 [1]"); if (close (1) == -1) syserr("child, close (1)"); if (dup (fd2 [1]) != 1) syserr("child, dup (pipe_dsc [1]"); if (close (fd2 [1]) == -1) syserr("child, close (pipe_dsc [1])"); if (close (fd2 [0]) == -1) syserr("chiled, close (fd2 [0]"); execl("./client", "client", (char*) 0); syserr ("child, execvp"); exit (0); default: printf("%d\n", fd1[0]); printf("%d\n", fd1[1]); printf("%d\n", fd2[0]); printf("%d\n", fd2[1]); if (close (fd1[0] != -1)) syserr("parent, close (fd1[0])"); if (close (fd2[1] != -1)) syserr("parent, close (fd2[1])"); while (fgets(message, sizeof(message), stdin) != NULL) { if (write (fd1 [1], message, sizeof(message) - 1) == -1) syserr("write"); if ((buf_len = read(fd2[0], response, BUF_SIZE -1)) == -1) syserr("Error in read"); printf("%s%s", "response: ", response); } if (close (fd1 [1]) == -1) syserr("parent, close (pipe_dsc [0])"); if (close (fd2 [0]) == -1) syserr("parent, close (pipe_dsc [1])"); if (wait (0) == -1) syserr("wait"); exit (0); } /* switch (fork ()) */ } </code></pre> <p>And client.c</p> <pre><code>#include &lt;stdlib.h&gt; #include &lt;stdio.h&gt; #include &lt;unistd.h&gt; #include &lt;stdbool.h&gt; #include "err.h" #define BUF_SIZE 1024 int main (int argc, char *argv[]) { char buf[BUF_SIZE]; while (fgets(buf, sizeof(buf), stdin) != 0) { printf("%s%s","Write to stdout", buf); } return 0; } </code></pre> <p>I got the following mistake:</p> <pre><code>3 4 5 6 ERROR: parent, close (fd2[1]) (9; Bad file descriptor) </code></pre> <p>Any idea why I can't close descriptor?</p> <p>Thnaks in advance.</p>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USJosephConrad
    1. USJosephConrad
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COBecause it's not open. If you get EBADF, the file descriptor is either a completely bogus integer and was never initialised (eg assuming `open` succeeded), or it was once an fd but you've already closed it.
      singulars
      1. POClose file descriptor
      1. USNicholas Wilson
 

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