Added call tag. Updated read tag.

__call.cpp

@@ -0,0 +1,37 @@
+#include "__call.h"
+#include "Exception.h"
+#include "MString.h"
+#include <limits.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+namespace jet {
+   
+   __call::__call(coreutils::ZString &in, coreutils::MString &out, Global &global) : Tag(in, out, global) {
+      if(hasContainer)
+	throw coreutils::Exception("call cannot have a container.");	
+      if(!variableDefined(coreutils::ZString("pgm")))
+	throw coreutils::Exception("pgm keyword must be specified.");
+      pipe[fd]; // TODO: Get these pipes to work with name and input keywords.
+      dup2(0);
+      if(pid != fork()) {
+	 argv[0] = variables["pgm"]; // TODO: Need to peel off the program name only and pass as argv[0].	   
+	 for(ix = 1; ix <= ARG_MAX; ++ix) {    
+	    coreutils::MString arg("arg");
+	    arg << ix;
+	    if(variableDefined(arg))
+	      argv[ix] = variables[arg].c_str();
+	    else
+	      break;
+	 }
+	 argv[ix] == NULL;
+	 execve(variables["pgm"].c_str(), argv, NULL);	 
+	 exit(-1);
+      }
+      waitpid(&status);
+      
+   }
+   
+}