#include	"calld.h"#define	EXPALRM		45			/* alarm time to read expect string */static int		expalarm = EXPALRM;static volatile sig_atomic_t	caught_alrm;size_t			/* read one byte, handle timeout errors & DEBUG */exp_read(int fd, char *buf){	if (caught_alrm) {	/* test flag before blocking in read */		DEBUG("\nread timeout");		return(-1);	}	if (read(fd, buf, 1) == 1) {		DEBUG_NONL("%s", ctl_str(*buf));		return(1);	}	if (errno == EINTR && caught_alrm)		DEBUG("\nread timeout");	else		log_sys("read error");	return(-1);}static voidsig_alrm(int signo){	caught_alrm = 1;}int						/* return 0 if got it, -1 if not */expect_str(int fd, char *ptr){	char	expstr[MAXLINE], inbuf[MAXLINE];	char	c;	char	*src, *dst, *inptr, *cmpptr;	int		i, matchlen;	if (strcmp(ptr, "\"\"") == 0)		goto returnok;		/* special case of "" (expect nothing) */	/*	 * Copy expect string, converting escape sequences.	 */	for (src = ptr, dst = expstr; (c = *src++) != 0; ) {		if (c == '\\') {			if (*src == 0) {				sprintf(errmsg, "invalid expect string: %s\n", ptr);				return(-1);			}			c = *src++;		/* char following backslash */			switch (c) {			case 'r':				c = '\r';				break;			case 's':				c = ' ';				break;				/* room for lots more case statements ... */			default:				sprintf(errmsg, "unknown expect escape char: \\%s\n",				  ctl_str(c));				return(-1);			}		}		*dst++ = c;	}	*dst = 0;	matchlen = strlen(expstr);	if (signal(SIGALRM, sig_alrm) == SIG_ERR)		log_quit("signal error");	caught_alrm = 0;	alarm(expalarm);	do {		if (exp_read(fd, &c) < 0)			return(-1);	} while (c != expstr[0]);	/* skip until first chars equal */	cmpptr = inptr = inbuf;	*inptr = c;	for (i = 1; i < matchlen; i++) {	/* read matchlen chars */		inptr++;		if (exp_read(fd, inptr) < 0)			return(-1);	}	for ( ; ; ) {		/* keep reading until we have a match */		if (strncmp(cmpptr, expstr, matchlen) == 0)			break;		/* have a match */		inptr++;		if (exp_read(fd, inptr) < 0)			return(-1);		cmpptr++;	}returnok:	alarm(0);	DEBUG("\nexpect: got it");	return(0);}