#include <u.h>#include <libc.h> voidusage(void){	fprint(2, "usage: %s [-q] [-t seconds] command\n", argv0);	exits("usage");} struct {	char	*resp;	int	ok;} tab[] ={	{ "ok",			1 },	{ "connect",		1 },	{ "no carrier",		0 },	{ "no dialtone",	0 },	{ "error",		0 },	{ "busy",		0 },	{ "no answer",		0 },	{ "delayed",		0 },	{ "blacklisted",	0 },}; intwritewithoutcr(int fd, char *p, int i){	char *q, *e; 	/* dump cr's */	for(e = p+i; p < e; ){		q = memchr(p, '\r', e-p);		if(q == nil)			break;		if(q > p)			if(write(fd, p, q-p) < 0)				return -1;		p = q+1;	}	if(p < e)		if(write(fd, p, e-p) < 0)			return -1;	return i;} intreadln(int fd, char *buf, int n){	int c, i, sofar; 	sofar = 0;	buf[sofar] = 0;	while(sofar < n-1){		i = read(fd, buf+sofar, 1);		if(i <= 0)			return i;		c = buf[sofar];		if(c == '\r')			continue;		sofar++;		if(c == '\n')			break;	}	buf[sofar] = 0;	return sofar;} voiddocmd(char *cmd, int timeout, int quiet, int consfd){	char buf[4096];	int i;	char *p, *cp; 	if(timeout == 0){		if(*cmd == 'd' || *cmd == 'D')			timeout = 2*60;		else			timeout = 5;	} 	p = smprint("at%s\r", cmd);	for(cp = p; *cp; cp++){		write(1, cp, 1);		sleep(100);	}	free(p); 	alarm(timeout*1000);	for(;;){		i = readln(0, buf, sizeof(buf));		if(i <= 0){			rerrstr(buf, sizeof buf);			exits(buf);		}		if(!quiet)			writewithoutcr(consfd, buf, i);		for(i = 0; i < nelem(tab); i++)			if(cistrstr(buf, tab[i].resp)){				if(tab[i].ok)					goto out;				else					exits(buf);			}	}out:	alarm(0);} voidmain(int argc, char **argv){	int timeout;	int quiet;	int i;	int consfd; 	timeout = 0;	quiet = 0;	ARGBEGIN {	case 't':		timeout = atoi(EARGF(usage()));		break;	case 'q':		quiet = 1;		break;	default:		usage();	} ARGEND; 	if(argc < 1)		usage(); 	consfd = open("/dev/cons", ORDWR);	if(consfd < 0)		sysfatal("opening /dev/cons: %r"); 	for(i = 0; i < argc; i++)		docmd(argv[i], timeout, quiet, consfd); 	exits(0);}