casa6

#!/bin/sh

#-----------------------------------------------------------------------------

# affirm: Determine the Boolean value of a set of arguments

#-----------------------------------------------------------------------------

#

#   Copyright (C) 1993,1994

#   Associated Universities, Inc. Washington DC, USA.

#

#   This program is free software; you can redistribute it and/or modify

#   it under the terms of the GNU General Public License as published by

#   the Free Software Foundation; either version 2 of the License, or

#   (at your option) any later version.

#

#   This program is distributed in the hope that it will be useful,

#   but WITHOUT ANY WARRANTY; without even the implied warranty of

#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

#   GNU General Public License for more details.

#

#   You should have received a copy of the GNU General Public License

#   along with this program; if not, write to the Free Software

#   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

#

#   Correspondence concerning AIPS++ should be addressed as follows:

#          Internet email: aips2-request@nrao.edu.

#          Postal address: AIPS++ Project Office

#                          National Radio Astronomy Observatory

#                          520 Edgemont Road

#                          Charlottesville, VA 22903-2475 USA

#

#-----------------------------------------------------------------------------

# Usage: affirm [-a | -o ] [-s] [string1 [string2...]]

#-----------------------------------------------------------------------------

# affirm tests all of its arguments for truth or falsehood.  The arguments

# can be of the form "true"/"false", "t"/"f", "yes"/"no", "y"/"n", "on"/"off",

# "1"/"0" and are case insensitive.  It will print either "true" or "false"

# on stdout with a status return to match.

#

# Options:

#   -a     Produce the logical AND of all arguments (default).

#   -o     Produce the logical  OR of all arguments.

#   -s     Silent, just produce the exit status.

#

# Status return values correspond to the various phases of the operation

#    0:  true

#    1:  false

#    2:  unrecognized argument

#

# Notes:

#    1) The "-a" option returns immediately if it encounters a false argument;

#       remaining arguments are not checked for validity.  It can best be

#       thought of as searching for a "false" argument.  Even if the argument

#       list contains an unrecognized value the search still continues for a

#       "false" value.  If none are found and there were no unrecognized

#       arguments then it returns "true".

#

#       The "-o" option behaves similarly except that it searches for a "true"

#       argument.  Hence, to test the logical value of an environment variable

#       which may be undefined use

#

#          affirm -a $VAR

#

#       (or just 'affirm $VAR') to get a true result if VAR is blank, and use

#