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@@ -0,0 +1,77 @@
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+// Base code taken from http://www-h.eng.cam.ac.uk/help/tpl/unix/fork.html
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+// Fix for redhat suggested by Ptere Pramberger, peter@pramberger.at
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+#include <unistd.h>
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+#include <sys/wait.h>
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+#include <stdio.h>
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+#include <sys/types.h>
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+#include <signal.h>
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+void popen_sigchld_handler (int);
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+int childtermd;
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+
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+int main(){
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+ char str[1024];
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+ int pipefd[2];
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+ pid_t pid;
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+ int status, died;
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+
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+ if (signal (SIGCHLD, popen_sigchld_handler) == SIG_ERR) {
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+ printf ("Cannot catch SIGCHLD\n");
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+ _exit(-1);
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+ }
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+
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+ pipe (pipefd);
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+ switch(pid=fork()){
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+ case -1:
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+ printf("can't fork\n");
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+ _exit(-1);
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+
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+ case 0 : // this is the code the child runs
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+ close(1); // close stdout
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+ // pipefd[1] is for writing to the pipe. We want the output
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+ // that used to go to the standard output (file descriptor 1)
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+ // to be written to the pipe. The following command does this,
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+ // creating a new file descripter 1 (the lowest available)
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+ // that writes where pipefd[1] goes.
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+ dup (pipefd[1]); // points pipefd at file descriptor
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+ // the child isn't going to read from the pipe, so
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+ // pipefd[0] can be closed
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+ close (pipefd[0]);
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+
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+ //These are the commands to run, with success commented. dig and nslookup only problems
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+ //execl ("/bin/date","date",0); // 100%
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+ //execl ("/bin/cat", "cat", "/etc/hosts", 0); // 100%
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+ //execl ("/usr/bin/dig", "dig", "redhat.com", 0); // 69%
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+ //execl("/bin/sleep", "sleep", "1", 0); // 100%
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+ execl ("/usr/bin/nslookup","nslookup","redhat.com",0); // 90% (after 100 tests), 40% (after 10 tests)
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+ //execl ("/bin/ping","ping","-c","1","localhost",0); // 100%
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+ //execl ("/bin/ping","ping","-c","1","192.168.10.32",0); // 100%
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+ _exit(0);
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+
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+ default: // this is the code the parent runs
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+
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+ close(0); // close stdin
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+ // Set file descriptor 0 (stdin) to read from the pipe
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+ dup (pipefd[0]);
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+ // the parent isn't going to write to the pipe
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+ close (pipefd[1]);
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+ // Now read from the pipe
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+ fgets(str, 1023, stdin);
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+ //printf("1st line output is %s\n", str);
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+
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+ //while (!childtermd); // Uncomment this line to fix
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+
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+ died= wait(&status);
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+ //printf("died=%d status=%d\n", died, status);
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+ if (died > 0) _exit(0);
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+ else _exit(1);
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+ }
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+}
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+
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+void
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+popen_sigchld_handler (int signo)
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+{
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+ if (signo == SIGCHLD) {
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+ //printf("Caught sigchld\n");
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+ childtermd = 1;
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+ }
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+}
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Ton Voon