diff options
Diffstat (limited to 'config_test/child_test.c')
| -rw-r--r-- | config_test/child_test.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/config_test/child_test.c b/config_test/child_test.c new file mode 100644 index 0000000..2add3bc --- /dev/null +++ b/config_test/child_test.c @@ -0,0 +1,77 @@ +/* Base code taken from http://www-h.eng.cam.ac.uk/help/tpl/unix/fork.html + * Fix for redhat suggested by Ptere Pramberger, peter@pramberger.at */ +#include <unistd.h> +#include <sys/wait.h> +#include <stdio.h> +#include <sys/types.h> +#include <signal.h> +void popen_sigchld_handler (int); +int childtermd; + +int main(){ + char str[1024]; + int pipefd[2]; + pid_t pid; + int status, died; + + if (signal (SIGCHLD, popen_sigchld_handler) == SIG_ERR) { + printf ("Cannot catch SIGCHLD\n"); + _exit(-1); + } + + pipe (pipefd); + switch(pid=fork()){ + case -1: + printf("can't fork\n"); + _exit(-1); + + case 0 : /* this is the code the child runs */ + close(1); /* close stdout */ + /* pipefd[1] is for writing to the pipe. We want the output + * that used to go to the standard output (file descriptor 1) + * to be written to the pipe. The following command does this, + * creating a new file descriptor 1 (the lowest available) + * that writes where pipefd[1] goes. */ + dup (pipefd[1]); /* points pipefd at file descriptor */ + /* the child isn't going to read from the pipe, so + * pipefd[0] can be closed */ + close (pipefd[0]); + + /* These are the commands to run, with success commented. dig and nslookup only problems */ + /*execl ("/bin/date","date",0);*/ /* 100% */ + /*execl ("/bin/cat", "cat", "/etc/hosts", 0);*/ /* 100% */ + /*execl ("/usr/bin/dig", "dig", "redhat.com", 0);*/ /* 69% */ + /*execl("/bin/sleep", "sleep", "1", 0);*/ /* 100% */ + execl ("/usr/bin/nslookup","nslookup","redhat.com",0); /* 90% (after 100 tests), 40% (after 10 tests) */ + /*execl ("/bin/ping","ping","-c","1","localhost",0);*/ /* 100% */ + /*execl ("/bin/ping","ping","-c","1","192.168.10.32",0);*/ /* 100% */ + _exit(0); + + default: /* this is the code the parent runs */ + + close(0); /* close stdin */ + /* Set file descriptor 0 (stdin) to read from the pipe */ + dup (pipefd[0]); + /* the parent isn't going to write to the pipe */ + close (pipefd[1]); + /* Now read from the pipe */ + fgets(str, 1023, stdin); + /*printf("1st line output is %s\n", str);*/ + + /*while (!childtermd);*/ /* Uncomment this line to fix */ + + died= wait(&status); + /*printf("died=%d status=%d\n", died, status);*/ + if (died > 0) _exit(0); + else _exit(1); + } +} + +void +popen_sigchld_handler (int signo) +{ + if (signo == SIGCHLD) { + /*printf("Caught sigchld\n");*/ + childtermd = 1; + } +} |