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POworking with pipes
 

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  1. POworking with pipes
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    <p>I am trying to make this work but no luck, basically i need to write to the pipe and then make the pipe return back with the text i sent. I have a server.c and client.c , so i make the server.c run..., open a new terminal and then run the client.. the problem is that the client doesnt do anything when i run it.. I am sure i am missing something.. like closing the pipe. i am not sure.. I would really appreciate some guidance</p> <p>server.c</p> <pre><code>#include &lt;stdio.h&gt; #include &lt;errno.h&gt; #include &lt;ctype.h&gt; #include &lt;sys/types.h&gt; #include &lt;sys/stat.h&gt; #include &lt;fcntl.h&gt; #include &lt;string.h&gt; #define PIPE1 "PIPE1" #define PIPE5 "PIPE5" #define MAX_BUF_SIZE 255 int main(int argc, char *argv[]) { int rdfd1,rdfd2,rdfd3,rdfd4, wrfd1,wrfd2,wrfd3,wrfd4,ret_val, count, numread1,numread2,numread3,numread4; char buf1[MAX_BUF_SIZE]; char buf2[MAX_BUF_SIZE]; char buf3[MAX_BUF_SIZE]; char buf4[MAX_BUF_SIZE]; /* Create the first named - pipe */ ret_val = mkfifo(PIPE1, 0666); if ((ret_val == -1) &amp;&amp; (errno != EEXIST)) { perror("Error creating the named pipe"); return 1; } ret_val = mkfifo(PIPE5, 0666); if ((ret_val == -1) &amp;&amp; (errno != EEXIST)) { perror("Error creating the named pipe"); return 1; } /* Open the first named pipe for reading */ rdfd1 = open(PIPE1, O_RDONLY); /* Open the first named pipe for writing */ wrfd1 = open(PIPE5, O_WRONLY); /* Read from the pipes */ numread1 = read(rdfd1, buf1, MAX_BUF_SIZE); buf1[numread1] = '0'; printf("Server : Read From the pipe : %sn", buf1); /* * Write the converted content to * pipe */ write(wrfd1, buf1, strlen(buf1)); } </code></pre> <p>client.c</p> <pre><code>#include &lt;errno.h&gt; #include &lt;stdio.h&gt; #include &lt;stdlib.h&gt; #include &lt;string.h&gt; #include &lt;unistd.h&gt; #include &lt;ctype.h&gt; #include &lt;sys/types.h&gt; #include &lt;sys/stat.h&gt; #include &lt;fcntl.h&gt; #define PIPE1 "PIPE1" #define PIPE5 "PIPE5" #define MAX_BUF_SIZE 255 int main(int argc, char *argv[ ]) { pid_t childpid; int error; int i; int nprocs; /* check command line for a valid number of processes to generate */ int wrfd1, rdfd1, numread; char rdbuf[MAX_BUF_SIZE]; if ( (argc != 2) || ((nprocs = atoi (argv[1])) &lt;= 0) ) { fprintf (stderr, "Usage: %s nprocs\n", argv[0]); return 1; } for (i = 1; i &lt; nprocs; i++) { /* create the remaining processes */ if ((childpid = fork()) == -1) { fprintf(stderr, "[%ld]:failed to create child %d: %s\n", (long)getpid(), i, strerror(errno)); return 1; } /* Open the first named pipe for writing */ wrfd1 = open(PIPE5, O_WRONLY); /* Open the second named pipe for reading */ rdfd1 = open(PIPE1, O_RDONLY); if (childpid) break; char string1[100]; if(sprintf(string1, "This is process %d with ID %ld and parent id %ld\n", i, (long)getpid(), (long)getppid())) { write(wrfd1,string1, strlen(string1)); } /* Read from the pipe */ numread = read(rdfd1, rdbuf, MAX_BUF_SIZE); rdbuf[numread] = '0'; printf("Full Duplex Client : Read From the Pipe : %sn", rdbuf); } return 0; } </code></pre>
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    1. PO
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    1. PTQuestion
    1. USJonathan Leffler
    1. USuser975582
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    1. PO
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    1. COPlease don't edit or remove your erroneous code. The reactions and answers lose their context when you remove it.
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      1. POworking with pipes
      1. USwildplasser
 

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