Use TIOCGWINSZ to reduce the default -Owidth during interactive use

on terminals narrower than 79 columns and the default -Oindent on
terminals narrower than 66 columns.
Requested by and feedback from pirofti@;
mpi@ and juanfra@ also like the general direction.

1 files changed, 14 insertions, 2 deletions

diff --git a/main.c b/main.c
index e65d90a1..7ae27dca 100644
--- a/main.c
+++ b/main.c
@@ -1,7 +1,7 @@
-/*	$Id: main.c,v 1.303 2018/02/23 16:47:10 schwarze Exp $ */
+/*	$Id: main.c,v 1.304 2018/04/13 19:55:30 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2010-2012, 2014-2017 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010-2012, 2014-2018 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2010 Joerg Sonnenberger <joerg@netbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -19,7 +19,9 @@
 #include "config.h"
 
 #include <sys/types.h>
+#include <sys/ioctl.h>
 #include <sys/param.h>	/* MACHINE */
+#include <sys/termios.h>
 #include <sys/wait.h>
 
 #include <assert.h>
@@ -120,6 +122,7 @@ main(int argc, char *argv[])
 	struct manconf	 conf;
 	struct mansearch search;
 	struct curparse	 curp;
+	struct winsize	 ws;
 	struct tag_files *tag_files;
 	struct manpage	*res, *resp;
 	const char	*progname, *sec, *thisarg;
@@ -316,6 +319,15 @@ main(int argc, char *argv[])
 	    !isatty(STDOUT_FILENO))
 		use_pager = 0;
 
+	if (use_pager &&
+	    (conf.output.width == 0 || conf.output.indent == 0) &&
+	    ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1) {
+		if (conf.output.width == 0 && ws.ws_col < 79)
+			conf.output.width = ws.ws_col - 1;
+		if (conf.output.indent == 0 && ws.ws_col < 66)
+			conf.output.indent = 3;
+	}
+
 #if HAVE_PLEDGE
 	if (!use_pager)
 		if (pledge("stdio rpath", NULL) == -1)