#!/bin/csh -f
#+
# wftv -- wait for new TV image
#
# Purpose:
#	Loop until a new "cam*.fits" image appears in the nightly directory,
#	and return the name of the image
#
# Usage:
#	wftv [-silent]
# 
# Arguments:
#	-silent = do not echo the name of the TV image
# 
# Output:
#	Name of the TV image is echoed to STDOUT
# 
# Restrictions:
#	None
# 
# Exit values:
#	 0 = normal completion
#	 1 = wrong number of arguments
#
# Example:
#	1) Wait for a new TV image to appear and echo the name:
#		wftv
# 
# 	2) Wait for new TV image to appear and silently return:
#		wftv -silent
#-
# Modification history:
#	2002-Jul-02	GDW	Original version
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd [-silent]"

set verb = 1
set interval = 1

# check flags...
if ( "$1" == "-silent" ) then
    set verb = 0
    shift
endif

# verify args...
if ( $#argv > 0 ) then
  printf "$usage\n"
  exit 1
endif

# check the current TV image name...
set last = `lasttvimage`

# loop until image changes...
while (1)
    set new = `lasttvimage`
    if ( "$new" != "$last" ) then
	break
    endif
    sleep $interval
end

# echo name if desired...
if ( $verb ) then
    printf "%s\n" $new
endif
exit