richard

#include "api.h"#include "lib.h"#include "errno.h"#define WIDTH 80#define DATA_LEN ((WIDTH-4)/3)// dump the hex of a file.static const char* USAGE = "Usage: xd [-c count] filename\n";static void out(char c) {	char val = c&0xf;	if(val<10)		putch('0'+val);	else		putch('A'+val-10);}int main(int argc,char** argv) {	int fd=0;	char *filename=0;	int count=0;	char** arg=argv;	while(*++arg) {		if(strncmp("-c",*arg,3)==0) {			++arg;			if(*arg) {				count=atoi(*arg);				if(count==0) {					print(USAGE);					return 1;				}			} else {				print(USAGE);				return 1;			}			continue;		}		filename=*arg;	}	if(filename) {		fd=sys_open(filename,0);		if(fd==-1) {			printf("Error opening '%s': %s\n",argv[1],strerror(errno));			return 1;		}	}	u8 data[DATA_LEN];	int eof=0;	int total_read=0;	while(!eof) {		if(count && total_read>=count)			break;		int to_read = total_read+DATA_LEN> count ? count-total_read :DATA_LEN;		memset(data,0,sizeof(data));	int br=sys_read(fd,data,to_read);	if(br==-1) {		printf("Error reading from %d: %s\n",fd,strerror(errno));		return 1;	}	if(br==0) {		return 0;	}	while(br<DATA_LEN) {		int br2=sys_read(fd,data+br,to_read-br);		if(br2==0) { eof=1; break; }		if(br==-1) {			printf("Error reading from %d: %s\n",fd,strerror(errno));			return 1;		}		br+=br2;	}	total_read+=br;	// put hex data.	for(int i=0;i<br;++i) {		out(data[i]>>4);		out(data[i]);	}	// make it all line up	for(int i=br;i<DATA_LEN;++i) {		putch(' '); putch(' ');	}	print("    ");	for(int i=0;i<br;++i) {		if(data[i]>0x20 && data[i]<0x7f)			putch(data[i]);		else			putch('.');	}	putch('\n');}	return 0;}