msh in its own long standing directory now

334/homework/3/msh.c

@@ -1,111 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/wait.h>
-#include <time.h>
-#include <sys/types.h>
-
-#define PROMPT "msh> "
-#define EXIT_CMD "exit"
-#define MAX_BUF 121
-
-// Statuses from builtin responses
-#define RESP_HELP 1
-#define RESP_DATE 2
-#define RESP_ECHO 3
-#define RESP_SHELL 4
-
-void echo(const char*);
-void remove_newline(char*);
-void exit_branch(const char*);
-int  builtin_response(char*);
-
-
-int main(void) {
-	char buffer[MAX_BUF];
-	while(1) {
-		printf("%s", PROMPT);
-		fgets(buffer, MAX_BUF, stdin);
-		// Deal with EOF input
-		if(!strlen(buffer)) {
-			exit(0);
-		}
-		exit_branch(buffer);
-
-		remove_newline(buffer);
-		int status = builtin_response(buffer);
-		// the switch in case we need to add more response flags later
-		switch(status) {
-			case RESP_ECHO: 
-				echo(buffer);
-			case RESP_SHELL: // shell command handler was used
-				continue;
-		}
-		memset(buffer, 0x00, MAX_BUF); // reset buffer after each usage
-	}
-	return 0;
-}
-
-void echo(const char* buf) {
-	printf("%s\n", buf);
-}
-
-
-void remove_newline(char* buf) {
-	char* c = buf;
-	while(*c != '\n') { c++; }
-	*c='\0';
-}
-
-void exit_branch(const char* buf) {
-	if(!strcmp(buf, EXIT_CMD)) {
-		exit(0);
-	}
-}
-
-int builtin_response(char* buffer) {
-#define STRING_DELIMITER " "
-#define TIME_FMT "%D"
-	exit_branch(buffer);	// exit is builtin so here we are
-	if(!strcmp(buffer, "help")) {
-		echo("enter Linux commands, or ‘exit’ to exit");
-		return RESP_HELP;
-	}
-
-	// Printout the date today
-	if(!strcmp(buffer, "date")) {
-		static char date[64];
-		time_t now = time(0);
-		strftime(date, sizeof(date), TIME_FMT, localtime(&now));
-		echo(date);
-		return RESP_DATE;
-	}
-
-	char *tokens[64];
-	int idx = 0;
-	for(char* cur = strtok(buffer, STRING_DELIMITER); cur != NULL; cur=strtok(NULL, STRING_DELIMITER)) { 
-#ifdef DBG_LINE
-		printf("%s ", cur);
-#endif
-		tokens[idx] = cur;
-		idx++;
-	}
-
-	// Execute child process
-	pid_t child = fork();
-	if(child != 0) {
-		int status_child = wait(NULL);
-		if(status_child == 127) {
-			printf("msh: %s: %d", tokens[0], status_child);
-		}
-	}
-	else {
-		execvp(tokens[0], tokens);
-	}
-	// Cleanup pointers
-	for(int i = 0; i< 64; i++) {
-		tokens[i] = NULL;
-	}
-
-}