#include <stdio.h>

/*  HEX standard input to standard output */
void HEX_digit(short di, FILE *file);

main(int argc, char *argv[])
{	short	c;
	short	hi, low;
	short	nl;
	FILE	*file;
	FILE	*outFile;

if(argc!=3) {printf("Opps!\n");return;}
file=fopen(argv[1],"r");
if(file==0) {printf("File %s failed to open.\n",argv[1]);return;}
outFile=fopen(argv[2],"r");
if(outFile!=0) {printf("File %s already exists.\n",argv[2]);fclose(file);fclose(outFile);return;}
outFile=fopen(argv[2],"w");
if(outFile==0){printf("Could not create file %s.\n",argv[2]);fclose(file);return;}
nl=0;
while ( (c=getc(file))!=EOF ) {
	hi=c/16;low=c-16*hi;
	HEX_digit(hi,outFile);HEX_digit(low,outFile);
	nl++;
	if(nl>15) { nl=0; putc('\n',outFile);} else putc(' ',outFile);
	}
putc('\n',outFile);
fclose(file);
fclose(outFile);
}

void HEX_digit(short di, FILE *file)
{
if(di>9) putc('a'-10+di,file); else putc('0'+di,file);
}