#!/bin/ksh
#set -x
#
# Many codes require specific LD_LIBRARY_PATH settings,
# variables to point to specific license server nodes,
# and global environmental variables to be set. Or 
# perhaps you want to record a log of program usage. 
# It is best to install such programs in directories
# NOT in the user search path; and to have users NOT
# set these variables in their .cshrc, .bashrc, .login,
# .profile files. It is best to create a directory of
# wrappers for each application and to place that 
# directory in the user search path. These wrappers
# set up the required environment. 
# This avoids many problems; especially if you want to
#
#  o easily access multiple versions of a code 
#  o make a log entry for each program execution
# 
# Another approach it to make a single command that
# writes the setup information to standard output
# for a particular program; and then use aliases
# to easily "source" this information. An excellent
# example of this approach is the modules(1) 
# utility, which includes commands to unload and
# load environmental information.
# 
export LD_LIBRARY_PATH
export LM_LICENSE_FILE
export PATH
#####################
# function to list available wrapper commands
LIST(){
echo "known commands:"
[ -d /usr/local/wrapper ] && (cd /usr/local/wrapper;ls)
}
#####################
# process a direct call to the wrapper command instead of
# one of it's links.
WRAPPER(){
   case "$*" in
   ################
   generate)
      #
      # Generate all the links in the /usr/local/wrapper
      # directory. This is the directory to put in the
      # user's search path.
      # TIP: you can wipe out the directory to make sure
      #      old commands are not available and regenerate
      #      it with this option
      # make sure the directory exists
      #
      mkdir -p /usr/local/wrapper
      chmod a=xr,u+w /usr/local/wrapper
      #
      #
      # add the links to this script. A variant is to read
      # this list from a file.
      for NAME in \
         command1 \
         acroread \
	 fortran \
	 debugger \
	 c89 \
         $NULL
      do
         [ -L "$NAME" ] || ln  $0 /usr/local/wrapper/$NAME
      done
      echo 'wrapper directory contents'
      LIST
      exit
   ;;
   ################
   -h|--help|-help|help) USAGE;exit;;
   ################
   '') LIST;exit ;;
   ################
   *)
      echo 'unknown wrapper option'
      USAGE
      exit
   ;;
   ################
   esac
}
#####################
# usage
USAGE(){
cat <<\EOF
________________________________________________________________________________
The wrapper(1) script allows an administrator to easily maintain a large number
of wrappers around installed utilities. 

To display a list of commands in /usr/local/wrapper
   wrapper

To build or rebuild the /usr/local/wrapper/ directory the adminstrator enters:
   wrapper generate

To display this help
   wrapper help

The adminstrator edits the wrapper script and adds a case statement block for
each command to be wrapped.

John S. Urban
________________________________________________________________________________
EOF
}
#####################
#
# set CMD to a complete path and set up the 
# environment for the command
# or execute a command and exit.
#
VERB=`basename "$0"`
CMD=/mnt/applications/$VERB
case "$VERB" in
###################################################
command1)
   LD_LIBRARY_PATH=/mnt/applications/code1/lib:$LD_LIBRARY_PATH
   . /mnt/applications/code1/setup.sh
   CMD=/mnt/applications/code1/command1
;;
###################################################
acroread)
   CMD=/mnt/applications/AcROREAD4/bin/acroread
;;
###################################################
fortran)
   if [ "$*" = '' ]
   then
   cat <<\EOF
   set the COMPILER variable to one of ...
   ifort_11  Intel ifort compiler version 11.0
   ifort_10  Intel ifort compiler version 10.0
   gfortran
   g95_092   g95 version 0.92
        :
        :
EOF
      exit
   fi
   COMPILER=${COMPILER:-ifort_11}
   case "$COMPILER" in
   ifort_11)
      LM_LICENSE_FILE=28518@license_server
      . /mnt/applications/intel_fc_11.0/setup.sh
      CMD=ifort
   ;;
   ifort_10)
      LM_LICENSE_FILE=28518@license_server
      . /mnt/applications/intel_fc_10.0/setup.sh
      CMD=ifort
   ;;
   g95_092|g95)
      CMD=/usr/local/bin/g95
   ;;
   gfortran)
      CMD=/usr/bin/gfortran
   ;;
   *)
      echo 'unknown compiler version'
      exit
   ;;
   esac
;;
###################################################
c89)
   LD_LIBRARY_PATH=/mnt/applications/code1/lib:$LD_LIBRARY_PATH
   CMD=/usr/share/bin/cc
;;
###################################################
wrapper)
   WRAPPER "${@}"
   exit
;;
###################################################
*)
   echo "unknown wrapper command"
   CMD=echo
;;
###################################################
esac
###################################################
# execute command
$CMD "${@}"
###################################################