[comp.unix.questions] Determining screen width

roger@.uucp (Roger Droz) (11/08/90)

Using termcap/terminfo routines seems like a very expensive way of
determining the screen width, if that's the only terminal capability one
is interested in.

I have seen several programs (such as less) use ioctl calls, but I know
that not all of the Un*x systems in house have these.  Code that uses
ioctl invariably also uses tgetnum() if all else fails.  That big
termcap/terminfo library still has to be linked in only to be used
once.

#ifdef TIOCGWINSZ
 	if (ioctl(2, TIOCGWINSZ, &w) == 0 && w.ws_col)
		sc_width = w.ws_col;
	else
#ifdef WIOCGETD
	if (ioctl(2, WIOCGETD, &w) == 0 && w.uw_width)
		sc_width = w.uw_width/w.uw_hs;
	else
#endif
#endif
 		sc_width = tgetnum("co");
 	if (dumb || sc_width < 0)
  		sc_width = 80;

What do you net people this of the following as a terse, portable way of
determining screen width? 

FILE *tputfile;
int stdoutwidth;

if ((tputfile = popen("tput cols", "r")) != NULL) {
	if (fscanf(tputfile,"%d", &stdoutwidth) < 1)
		stdoutwidth = 80;
	(void) pclose(tputfile);
}
____________
               Roger Droz       UUCP: uw-beaver!gtisqr!roger
()       ()    Maverick MICRoSystems / Global Technology International
 (_______)     Mukilteo, WA 
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