assignment 1

cmd.h

@@ -0,0 +1,49 @@
+#ifndef CMD_H
+#define CMD_H
+
+#include <stdbool.h>
+#include "scanner.h"
+#define INITIAL_ARRAY_SIZE 4
+
+// models one executable + options
+// thanks to the use of pointers, not as wasteful of memory as it might at first appear.
+// this struct makes it much easier to pass a TokenList to an exec() system call.
+typedef struct Command {
+  char **arguments;
+  char *command;
+  int capacity;
+  int numArguments;
+} Command;
+
+// models a list of commands
+// used to properly handle piping.
+typedef struct CommandList {
+  Command *commands;
+  int capacity;
+  int numCommands;
+} CommandList;
+
+// models one complete chain of numCommands
+// For lab1, somewhat barebones. 
+// Will be expanded upon when we implement redirection/background processes/piping
+typedef struct Chain {
+  CommandList commands;
+  bool runInBackground;
+} Chain;
+
+
+void freeCommand(Command cmd);
+void freeChain(Chain chain);
+
+Command buildCommand(List *lp);
+Chain buildChain(List *lp);
+
+void executeChain(Chain chain, int* status);
+#if EXT_PROMPT
+bool executeBuiltin(Command cmd, int *status, bool *debug);
+#else
+bool executeBuiltin(Command cmd, int *status);
+#endif
+
+void printChain(Chain chain);
+#endif