#include <stdio.h>

#define MAXLEN 100

FILE *fd;
char buffer[MAXLEN];

main(argc,argv)
int argc;
char *argv[];
{
	int n=4;
	int i;
	int argn=argc;

	if(argc<2) {
		printf("Useage: %s [-n] filenames\n",argv[0]);
		exit(50);
	}

	for(i=1;i<argc;i++) {
		if('-'==*argv[i]) {
			n=atoi(argv[i]+1);
			if(n<1||n>MAXLEN) {
				printf("\nInvalid option: %s\n",argv[i]);
				exit(50);
			}
			argn--;
		} else {
			if(!(fd=fopen(argv[i],"r"))) {
				printf("\nUnable to open %s\n",argv[i]);
				exit(20);
			} else {
				if(argn>2) printf("\n%s:\n\n",argv[i]);
				do_strings(fd,n);
				fclose(fd);
			}
		}
	}
}

do_strings(file,numchars)

register FILE *file;
register int numchars;

{
	register char *bufptr=buffer;
	register int bufcnt=0;
	register int printing=0;

	register int c;
	int i;

	while((c=fgetc(file))!=EOF) {
		if(c>=' '&&c<127) {
			if(printing) putchar(c);
			else {
				*bufptr++=c;
				if(++bufcnt>=numchars) {
					bufptr=buffer;
					for(i=0;i<bufcnt;i++) putchar(*bufptr++);
					printing=1;
				}
			}
		} else {
			if(printing) putchar('\n');
			printing=0;
			bufptr=buffer;
			bufcnt=0;
		}
	}
}