working toward a process-group signalling system

5 files changed, 83 insertions, 24 deletions

diff --git a/tools/hi-q.c b/tools/hi-q.c
index a065ad0..14ca5ec 100644
--- a/tools/hi-q.c
+++ b/tools/hi-q.c
@@ -197,17 +197,16 @@ int main(int argc, char** argv, char const * const * env) {
     }
     if (job.size()) filter.push_back(job);
   }
-  if (verbose) for (vector<VS>::const_iterator job = filter.begin();
-        job != filter.end(); job++) {
-    cerr << "Filter: ";
-    for (VS::const_iterator token = job->begin();
-        token != job->end(); token++){
+  unsigned int nkids = filter.size();
+  if (verbose) for (unsigned int ii = 0; ii < nkids; ii++) {
+    cerr << "hi-q filter[" << ii << "] :; ";
+    for (VS::const_iterator token = filter[ii].begin();
+        token != filter[ii].end(); token++){
       cerr << *token << " ";
     }
     cerr << endl;
   }
 
-  int nkids = filter.size();
   vector<pid_t> kidpid(nkids);  // indexed by kid number
 
 // At this point, there are some loop invariants;
@@ -218,7 +217,7 @@ int main(int argc, char** argv, char const * const * env) {
 //     doesn't choose it.  That allows N-1 of the kids
 //     to close it and dup() something useful onto it.
 
-  for (int ii=0; ii < nkids; ii++){  /* loop over all kids */
+  for (unsigned int ii=0; ii < nkids; ii++){  /* loop over all kids */
     int datapipe[2];
     int kid_end;
 
@@ -256,6 +255,16 @@ int main(int argc, char** argv, char const * const * env) {
     kidpid[ii] = fork();
     if (!kidpid[ii]) {  /*** child code ***/
 
+      pid_t kidgroup(0);    // process group for all kids is
+                            // equal to pid of kid#0
+      if (ii) kidgroup = kidpid[0];
+      if (setpgid(0, kidgroup) != 0) {
+        cerr << "setpgid failed! " << errno << " ... ";
+        perror(0);
+      }
+      cerr << "kid [" << ii << "] starts: " << getpid() 
+        << "  kidpid[0] " << kidpid[0]
+        << endl;
 // Now that we are through creating pipes, we don't
 // need to continue blocking fd1:
       close(1);
@@ -295,10 +304,14 @@ int main(int argc, char** argv, char const * const * env) {
       panic(ex_syserr);
     }
     close(kid_end);
-#ifdef more_testing
-    fprintf(stderr, "forked kid #%d (%d) piping %d\n",
-                ii, kidpid[ii], kid_end);
-//    sleep(1); /* let kid run a while */
+// it is important to let kid#0 run a while;
+// otherwise it won't fully exist when the other kids start,
+// and depending race conditions, the setpgid could fail
+    if (1) usleep(0);
+#if 1
+    cerr << "forked kid #" << ii 
+            << " (" << kidpid[ii] << ") "
+            << endl;
 #endif
   }
 
@@ -307,7 +320,7 @@ int main(int argc, char** argv, char const * const * env) {
   close(0);             // the reading end of stdin was
                         // delegated to the first child
 
-  for (int ii=0; ii<nkids-1; ii++){        /* loop over N-1 kids */
+  for (unsigned int ii=0; ii<nkids-1; ii++){        /* loop over N-1 kids */
                                         /* not last kid */
 #ifdef testing
     blurb(ii, kidpid);
diff --git a/tools/hi-test.c b/tools/hi-test.c
new file mode 100644
index 0000000..3befedd
--- /dev/null
+++ b/tools/hi-test.c
@@ -0,0 +1,7 @@
+
+#include <iostream>
+
+using namespace std;
+int main(){
+  cerr << getpid() << " : " << getpgid(0) << endl;
+}
diff --git a/tools/hi-test.conf b/tools/hi-test.conf
new file mode 100644
index 0000000..d09ba81
--- /dev/null
+++ b/tools/hi-test.conf
@@ -0,0 +1,3 @@
+hi-test
+hi-test
+hi-test
diff --git a/tools/makefile b/tools/makefile
index 8de2bd4..3803e44 100644
--- a/tools/makefile
+++ b/tools/makefile
@@ -10,7 +10,7 @@ CC= /usr/bin/g++ -Wall -g -I $(HOME)/lib/include
 
 .SECONDARY : # do not remove any intermediate files
 
-progs = pido hi-q skrewt
+progs = pido hi-q skrewt hi-test
 
 all: $(progs)
 
diff --git a/tools/skrewt.c b/tools/skrewt.c
index 8ae4db4..b81f0ea 100644
--- a/tools/skrewt.c
+++ b/tools/skrewt.c
@@ -21,7 +21,8 @@ void usage(const int sts){
 "\n"
 "  Typically used as a filter in a pipeline, along with spamc -E\n"
 "  Options\n"
-"    -h      print this msg (and exit immediately).\n"
+"    -help              print this msg (and exit immediately).\n"
+"    -maxsize ii        msg size in bytes; anything bigger will be rejected.\n"
 "\n"
 "  Messages containing the string '-please-bounce-this-' will be rejected.\n"
 "  Messages with no date will be rejected.\n"
@@ -82,17 +83,53 @@ string toLower(const std::string& a){
   return rslt;
 }
 
-
+////////////////
 string ltrim(string foo){
   size_t where = foo.find_first_not_of(" \t\r\n");
   if (where == foo.npos) return foo;
   return foo.substr(where);
 }
 
-int main(int argc, char** argv){
-  if (argc > 1) {
-    if (argv[1] == string("-h")) usage(0);
-    usage(1);
+////////////////
+// little utility to help with argument parsing:
+//
+int prefix(const string shorter, const string longer){
+  return shorter == longer.substr(0, shorter.length());
+}
+
+////////////////////////////////////////////////////////////
+int main(int _argc, const char** _argv){
+////  pid_t pid = getpid();
+////  cout << pid << endl;
+////  cout << getpgid(pid) << endl;
+  int argc(_argc);
+  const char **argv(_argv);
+  string progname(*argv); argv++; argc--;
+
+  int maxsize(1000000);
+
+  while (argc) {
+    string arg(*argv); argv++; argc--;
+    if (arg.substr(0,2) == "--") arg = arg.substr(1);
+    if (prefix(arg, "-help")) {
+      usage(0);
+    }
+    if (prefix(arg, "-maxsize")) {
+      if (!argc) {
+        cerr << "Option -maxsize requires an argument" << endl;
+        exit(1);
+      }
+      maxsize = atoi(*argv); argv++; argc--;
+    }
+    if (arg.substr(0,1) == "-") {
+      cerr << "Unrecognized option '" << arg << "'" << endl;
+      cerr << "For help, try:  " << progname << " -help" << endl;
+      exit(1);
+    } else {
+      cerr << "Extraneous verbiage '" << arg << "'" << endl;
+      cerr << "For help, try:  " << progname << " -help" << endl;
+      exit(1);
+    }
   }
 
   int inheads(1);
@@ -101,7 +138,6 @@ int main(int argc, char** argv){
   int textlines(0);
   int gotdate(0);
   int msgsize(0);
-  int msgmax(1000000);
   for (;;){
     if (cin.eof()) break;
     if (cin.bad()) return 1;
@@ -119,8 +155,8 @@ int main(int argc, char** argv){
         string line;
         if (getline(cin, line).fail()) continue;
         msgsize += line.length()+1;
-        if (msgsize > msgmax) {
-          cerr << "skrewt rejection: bigger than " << msgmax << endl;
+        if (msgsize > maxsize) {
+          cerr << "skrewt rejection: bigger than " << maxsize << endl;
           exit(1);
         }
         header += "\n" + line;
@@ -185,8 +221,8 @@ int main(int argc, char** argv){
       string line;
       if (!getline(cin, line).fail()) {
         msgsize += line.length()+1;
-        if (msgsize > msgmax) {
-          cerr << "skrewt rejection: bigger than " << msgmax << endl;
+        if (msgsize > maxsize) {
+          cerr << "skrewt rejection: bigger than " << maxsize << endl;
           exit(1);
         }
         if (line == "--" + boundary) {