richard

#include "api.h"#include "lib.h"#define ALWAYS_REPORT_EXIT_CODE 0#define PROMPT "->"#define BUF_LEN 256char curr_line[BUF_LEN];int count;int read_line() {	for(int i=0;i<BUF_LEN;++i) {		char c = getch();		switch(c) {			case 0: // null byte, probably a keyboard key we've not mapped yet.				--i;				continue;			case 8: // backspace.				i-=2;				continue;			case '\n':				c=0;			default:				curr_line[i]=c;				break;		}		if(c==0)			return i;	}	return -1;}int main(void) {	print("Welcome to the shell ;)\n");	for(;;) {		print(PROMPT);		flush();		int len=read_line();		if(len==-1) {			printf("\nLine too long!\n");			continue;		}		if(len==0)			continue;		int background=0;		if(curr_line[len-1]=='&') {			background=1;			curr_line[len-1]=0;		}		int program_fd =sys_open(curr_line,0);		if(program_fd==-1) {			printf("No such program: %s - errno=%d\n",curr_line,errno);			continue;		}		int retval=0;		int childpid=sys_fork();		switch(childpid) {			case -1: printf("Error forking: %d\n",childpid);					break;			case 0:				sys_exec(program_fd);				print("Could not execute program\n");				sys_exit(1);				// doesn't return...			default:				sys_close(program_fd);				if(background==1) {					printf("Running %d in background.\n",childpid);				}else{					sys_wait(&retval);					if(retval || ALWAYS_REPORT_EXIT_CODE)					printf("%s returned %d\n",curr_line,retval);				}				break;		}	}	return 0;}