process creation

src/built_in.c

@@ -3,6 +3,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
 #include <unistd.h>
 #include <linux/limits.h>
 

src/commands.c

@@ -2,6 +2,15 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <pthread.h>
+
+
 
 #include "commands.h"
 #include "built_in.h"
@@ -49,6 +58,23 @@ int evaluate_command(int n_commands, struct single_command (*commands)[512])
       return 0;
     } else if (strcmp(com->argv[0], "exit") == 0) {
       return 1;
+    }
+      else if(com->argv[0] > 0) {
+	pid_t pid;
+        pid = fork();
+
+        switch(pid)
+	{
+	  case -1 :
+	  printf("fail\n");
+	  case 0 :
+	  execv(com->argv[0], com->argv);
+	  printf("exec fail\n");
+	  default :
+	  wait((int*)0);
+	  printf("complete\n");
+	  exit(0);
+	}
     } else {
       fprintf(stderr, "%s: command not found\n", com->argv[0]);
       return -1;