#include	<u.h>#include 	<libc.h>#include	<bio.h> Biobuf	*fin;Biobuf	fout; #define	MINSPAN		6		/* Min characters in string (default) */#define BUFSIZE		70 void stringit(char *);int isprint(Rune); static int minspan = MINSPAN; static voidusage(void){	fprint(2, "usage: %s [-m min] [file...]\n", argv0);	exits("usage");} voidmain(int argc, char **argv){	int i; 	ARGBEGIN{	case 'm':		minspan = atoi(EARGF(usage()));		break;	default:		usage();		break;	}ARGEND	Binit(&fout, 1, OWRITE);	if(argc < 1) {		stringit("/fd/0");		exits(0);	} 	for(i = 0; i < argc; i++) {		if(argc > 2)			print("%s:\n", argv[i]); 		stringit(argv[i]);	} 	exits(0);} voidstringit(char *str){	long posn, start;	int cnt = 0;	long c; 	Rune buf[BUFSIZE]; 	if ((fin = Bopen(str, OREAD)) == 0) {		perror("open");		return;	} 	start = 0;	posn = Boffset(fin);	while((c = Bgetrune(fin)) >= 0) {		if(isprint(c)) {			if(start == 0)				start = posn;			buf[cnt++] = c;			if(cnt == BUFSIZE-1) {				buf[cnt] = 0;				Bprint(&fout, "%8ld: %S ...\n", start, buf);				start = 0;				cnt = 0;			}		} else {			 if(cnt >= minspan) {				buf[cnt] = 0;				Bprint(&fout, "%8ld: %S\n", start, buf);			}			start = 0;			cnt = 0;		}			posn = Boffset(fin);	} 	if(cnt >= minspan){		buf[cnt] = 0;		Bprint(&fout, "%8ld: %S\n", start, buf);	}	Bterm(fin);} intisprint(Rune r){	if (r != Runeerror)	if ((r >= ' ' && r < 0x7F) || r > 0xA0)		return 1;	return 0;}