Write a shell with history capabilities

process_chp3/osh_shell/history.h

@@ -0,0 +1,29 @@
+#ifndef __HISTORY_H__
+#define __HISTORY_H__
+
+#define MAXLEN 80
+#define HISTORY_SIZE 10
+
+typedef struct __HISTORY_ENTRY__ {
+  int line_number;
+  char command[MAXLEN];
+} history_entry_t;
+
+// Create new history file if not exists,
+// otherwise read last command count and return it
+int allocate_history(void);
+
+// Return last ten command in the history file
+history_entry_t *get_history(int);
+
+// Write a record in the history file
+int add_history(int, char *);
+
+// Read last command in the history file
+int last_command(char *);
+
+// Search nth command in the history file,
+// if not found nth command return -1.
+int nth_command(char *, int);
+
+#endif // __HISTORY_H__