#include <u.h>#include <libc.h>#include "drawterm.h" void*erealloc(void *v, ulong n){	v = realloc(v, n);	if(v == nil)		sysfatal("out of memory");	return v;} extern char* estrdup(char *); /* implemented in exportfschar*estrdup(char *s){	s = strdup(s);	if(s == nil)		sysfatal("out of memory");	return s;}*/char*estrappend(char *s, char *fmt, ...){	char *t;	va_list arg; 	va_start(arg, fmt);	t = vsmprint(fmt, arg);	if(t == nil)		sysfatal("out of memory");	va_end(arg);	s = erealloc(s, strlen(s)+strlen(t)+1);	strcat(s, t);	free(t);	return s;} /* *  prompt for a string with a possible default response */char*readcons(char *prompt, char *def, int raw){	int fdin, fdout, ctl, n;	char line[10];	char *s; 	fdin = open("/dev/cons", OREAD);	if(fdin < 0)		fdin = 0;	fdout = open("/dev/cons", OWRITE);	if(fdout < 0)		fdout = 1;	if(def != nil)		fprint(fdout, "%s[%s]: ", prompt, def);	else		fprint(fdout, "%s: ", prompt);	if(raw){		ctl = open("/dev/consctl", OWRITE);		if(ctl >= 0)			write(ctl, "rawon", 5);	} else		ctl = -1;	s = estrdup("");	for(;;){		n = read(fdin, line, 1);		if(n == 0){		Error:			close(fdin);			close(fdout);			if(ctl >= 0)				close(ctl);			free(s);			return nil;		}		if(n < 0)			goto Error;		if(line[0] == 0x7f)			goto Error;		if(n == 0 || line[0] == '\n' || line[0] == '\r'){			if(raw){				write(ctl, "rawoff", 6);				write(fdout, "\n", 1);			}			close(ctl);			close(fdin);			close(fdout);			if(*s == 0 && def != nil)				s = estrappend(s, "%s", def);			return s;		}		if(line[0] == '\b'){			if(strlen(s) > 0)				s[strlen(s)-1] = 0;		} else if(line[0] == 0x15) {	/* ^U: line kill */			if(def != nil)				fprint(fdout, "\n%s[%s]: ", prompt, def);			else				fprint(fdout, "\n%s: ", prompt);						s[0] = 0;		} else {			s = estrappend(s, "%c", line[0]);		}	}	return nil; /* not reached */}