ECHILD error at waitpid on Red Hat systems (Peter Pramberger and

Sascha Runschke - 1250191)


git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1213 f882894a-f735-0410-b71e-b25c423dba1c

3 files changed, 103 insertions, 0 deletions

diff --git a/config_test/Makefile b/config_test/Makefile
new file mode 100644
index 00000000..295696e9
--- /dev/null
+++ b/config_test/Makefile
@@ -0,0 +1,10 @@
+
+all: child_test.c
+        gcc -o child_test child_test.c
+
+test:
+        ./run_tests 10
+
+clean:
+        rm -f child_test
+
diff --git a/config_test/child_test.c b/config_test/child_test.c
new file mode 100644
index 00000000..e7d82106
--- /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 descripter 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;
+        }
+}
diff --git a/config_test/run_tests b/config_test/run_tests
new file mode 100755
index 00000000..e41db232
--- /dev/null
+++ b/config_test/run_tests
@@ -0,0 +1,16 @@
+#!/bin/ksh
+
+i=0
+success=0
+fail=0
+while [[ $i -lt $1 ]] ; do
+        ./child_test
+        if [[ $? -eq 0 ]] ; then
+                success=$(($success+1))
+        else
+                fail=$((fail+1))
+        fi
+        i=$(($i+1))
+done
+print "Success=$success Fail=$fail"
+[[ $fail -gt 0 ]] && exit 1