Stage 5

shell.c

@@ -7,12 +7,18 @@
 #include "shell.h"
 #include <sys/wait.h>
 
+int counter = 0;
+int historySize = 0;
+Command history[MAX_HISTORY_LENGTH];
 
 void run_shell() {
     int status;
     String input, arguments[MAX_INPUT_LENGTH], originalPath;
     char directory[MAX_PATH_LENGTH];
 
+	for (int i = 0; i < MAX_HISTORY_LENGTH; i++) {
+		history[i].line = malloc(sizeof(char) * MAX_INPUT_LENGTH);
+	}
     
     // Set the current directory to HOME
     if(getenv("HOME") != NULL) {
@@ -33,6 +39,7 @@ void run_shell() {
         // Alocate memory for the input & read user's input
         input = malloc(MAX_INPUT_LENGTH * sizeof(char));
         read_input(input);
+		add_history(input);
 
         // Tokenize to get the arguments
         tokenize(input, arguments);
@@ -55,6 +62,23 @@ void read_input(String input) {
         exit(EXIT_STATUS);
     }
 }
+
+void add_history(String input) {
+	if (strcspn(input, "!") > 0) {
+		history[counter].number = counter + 1;
+		strcpy(history[counter].line, input);
+		counter = (counter + 1) % MAX_HISTORY_LENGTH;
+		
+		if (historySize <= 20) {
+			historySize++;
+		}
+	} 
+}
+// 1 - ls
+// 2 - cd ..
+// 3 - getpath
+// ...
+// 20 - ...
 void tokenize(String input, String arguments[]) {
     String token = strtok(input, TOKENIZE_DELIM);
     int index = 1;
@@ -91,17 +115,22 @@ int run_command(String arguments[]) {
             setenv("/usr", "PATH", 1);
         }
 
-        //Implement the CD - command that changes the current directory.
-        // if(strcmp(arguments[0], "cd") == 0) {
-        //     if(arguments[1] == NULL) {
-        //         chdir(getenv("HOME"));
-        //     }
+		if (strcmp(arguments[0], "history") == 0) {
+			print_history();
+			return SUCCESS_STATUS;
+		}
 
-        //     if(chdir(arguments[1]) < 0) {
-        //         perror("ERROR");
-        //     }
-        //     return SUCCESS_STATUS;
-        // }
+        //Implement the CD - command that changes the current directory.
+        if(strcmp(arguments[0], "cd") == 0) {
+            if(arguments[1] == NULL) {
+                chdir(getenv("HOME"));
+            }
+
+            if(chdir(arguments[1]) < 0) {
+                perror("ERROR");
+            }
+            return SUCCESS_STATUS;
+        }
 
         
         // If the command was not found above, fork a child process and run the command there.
@@ -117,6 +146,21 @@ void get_directory(char directory[]) {
     }
 }
 
+void print_history() {
+	int index = 0;
+	int commandCounter = 0;
+	while (commandCounter < historySize && history[index].number != 1) {
+		index++;
+		commandCounter++;
+	}
+	
+	commandCounter = 1;
+	while (commandCounter < historySize) {
+		printf("%d - %s", commandCounter, history[index].line);
+		index = (index + 1) % MAX_HISTORY_LENGTH;
+		commandCounter++;
+	}
+}
 
 int execute_system_commands(String arguments[]) {
     int status;
@@ -136,4 +180,4 @@ int execute_system_commands(String arguments[]) {
     }
 
     return SUCCESS_STATUS;
-}
\ No newline at end of file
+}

shell.h

 /* shell.h */
 #define EXIT_STATUS 0
 #define SUCCESS_STATUS 1
+#define MAX_HISTORY_LENGTH 20
 #define MAX_INPUT_LENGTH 512
 #define MAX_PATH_LENGTH 512
 #define TOKENIZE_DELIM " \t\n|><&;"
@@ -18,6 +19,14 @@ typedef enum {
   true = 1
 } Boolean;
 
+/*
+*	Define command history struct
+*/
+typedef struct {
+	String line;
+	int number;
+} Command;
+
 /**
 *   Run the shell program
 */
@@ -28,6 +37,10 @@ void get_directory(char directory[]);
 */
 int execute_system_commands(String argruments[]);
 
+/*
+*	Prints history
+*/
+void print_history();
 
 /**
 *   Run the shell program
@@ -39,6 +52,11 @@ int run_command(String argruments[]);
 */
 void tokenize(String input, String argruments[]);
 
+/*
+*	Add input to history
+*/
+void add_history(String input);
+
 /**
 *   Run the shell program
 */