#!/bin/ksh
# @(#) capture.ksh 1.3 95/03/01
# syntax: capture [ outfile ]
# capture: captures current XENIX/UNIX console screen in a file
# 91/01/18 john h. dubois iii (john@armory.com)
# 92/03/17 Added '-' as special filename, and -t option.
# 92/09/27 Use awk instead of head, print, etc.; delete trailing spaces;
#          made filename be the default option;
#          trap INT & QUIT to reset echo mode
# 94/03/05 Make sure output file can be written before sending media copy seq.
# 95/02/01 Added [naw] options.
# 95/03/01 Fixed so '-' works as filename again.

unset ENV tty

name=${0##*/}
Usage="Usage: $name [-ahn] [-t<tty>] [-w<width>] [filename]"
typeset -i DelWhite=1 Width=0
WrapOff=false

while getopts :ahnt:w: opt; do
    case $opt in
    h)
	echo \
"$name: capture a XENIX/UNIX console screen into a file.
$Usage
filename is the name of the file to capture the screen into.  If no filename is
given, the screen will be captured into a file called \"screen\" in the current
directory.  A filename of \"-\" will cause output to go to the standard output.
A filename of \"-\" should only be used if the output of $name is redirected or
if a tty other than the current tty is given with -t.
Options:
-h: Print this help.
-n: Normally, $name removes trailing whitespace from the lines read from the
    screen, because the lines are as wide as the screen and so would cause the
    console to do a line wrap after every line, making it appear to be double-
    spaced.  If -n is given, trailing whitespace is not removed.  This can be
    used in cases where it is important that the lines in the file have a
    uniform width.
-w<width>: Truncate the output to <width> columns.  This can be used to e.g.
    remove the rightmost column of a display that includes a border, so that it
    can be displayed on the console without wrapping.  To do that, give a width
    one less than the screen width, for example, -w79.
-a: Add ANSI escape sequence to the output to turn off autowrap before the
    captured display and turn it back on after the captured display.  This
    allows full-width screen captures to be displayed without wrapping.  It
    will work on the console under SCO 3.2v4 and on terminals that implement
    the full set of ANSI X3.64-1979 screen attribute control sequences.
-t<tty>: Specify the tty name of the screen to capture.  The default is to
    capture the current screen.  If a screen other than the current screen is
    to be captured, it must have no other processes reading from it, or $name
    will compete for input with the other processes.  This generally means that
    it should be disabled."
	exit 0
	;;
    t)  [[ "$OPTARG" = */* ]] && tty=$OPTARG || tty=/dev/$OPTARG
	;;
    a)
	WrapOff=true;;
    w)
	Width=$OPTARG || exit 1;;
    n)
	DelWhite=0;;
    +?)
	print -u2 "$name: options should not be preceded by a '+'."
	exit 1
	;;
    :) 
	print -u2 "$name: Option '$OPTARG' requires a value.  Use -h for help."
	exit 1
	;;
    ?) 
	print -u2 "$name: $OPTARG: bad option.  Use -h for help."
	exit 1
	;;
    esac
done
 
# remove args that were options
let OPTIND=OPTIND-1
shift $OPTIND

case $# in
0) outfile=screen;;
1) outfile=$1;;
*) print -u2 \
"$name: Too many arguments.
$Usage
Usage -h for help."
   exit 1;;
esac

set -e

trap "stty echo; exit" INT QUIT

# fd 0: tty being captured, for doing stty and reading media copy output.
# fd 1: output file.
# fd 2: tty being captured, for writing escape sequences.

[ -n "$tty" ] && exec < $tty 2> $tty

# Make sure we can write the output file before echoing media copy sequence
if [ "$outfile" != - ]; then
    exec > $outfile
fi

stty -echo

$WrapOff && print -u2 -n "\033[?7l"	# turn off autowrap
print -u2 -n "\033[2i"			# echo 'media copy' sequence

# Save output and then write it in case capture output goes to the screen
# being read for some silly reason
awk -v DelWhite=$DelWhite -v Width=$Width '
{
    if (DelWhite)
	sub(" +$","")
    if (Width > 0)
	Lines[++i] = substr($0,1,Width)
    else
	Lines[++i] = $0
}
NR == 25 {
    for (i = 1; i <= 25; i++)
	print Lines[i]
    exit
}
'
$WrapOff && print -u2 -n "\033[?7h"	# turn on autowrap
stty echo