Shell Programming and Scripting

find
openssl
nawk
grep

OLDIFS="$IFS" ; IFS=":"

for CMD in openssl find nawk grep
do
        F=""
        for P in $PATH # Depends on IFS splitting, do not quote
        do
                [ -e "$P/$X" ] && F=1
                [ -z "$F" ] || break
        done

        if [ -z "$F" ]
        then
                echo "Required command $X not found in path" >&2
                exit 1
        fi
done

IFS="$OLDIFS"

unset ENV                                   # clear the environment
#---------------------------------------------------- set basic environment

typeset -x OS=$(uname -a | cut -d' ' -f1)   # find out the OS
                                            # read in standard environment
case "$OS" in
     AIX)
          . /etc/environment
          ;;

     Linux)
          . /etc/profile
          ;;

     *)
          . /etc/environment
          ;;
esac
                                            # set default TERM variable
case "$OS" in
     AIX)
          TERMDEF="$(termdef)"
          ;;

     Linux)
          TERMDEF="$TERM"
          ;;

      *)
          TERMDEF="$TERM"
          ;;

esac
typeset -x TERM=${TERMDEF:-'wyse60'}        # set default TERM variable
typeset -x LANG=C                           # default language environment
typeset -x EDITOR=vi                        # what else ? ;-))
typeset -x VISUAL=$EDITOR

typeset -x PATH="/usr/bin"                 # set the path
           PATH="$PATH:/bin"
           PATH="$PATH:/etc"
           PATH="$PATH:/usr/sbin"
           PATH="$PATH:/usr/ucb"
           PATH="$PATH:/sbin"
           PATH="$PATH:/usr/bin/X11"
           PATH="$PATH:/usr/local/bin"      # tools, home for scripts
           PATH="$PATH:/usr/local/sbin"     # -"-

if [ -z "$DEVELOP" ] ; then
     typeset -x FPATH="/usr/local/lib/ksh"  # set fnc path for fnc lib
     FPATH="$FPATH:/usr/local/bin"
     FPATH="$FPATH:/usr/local/sbin"
else
     typeset -x FPATH=~/lib        # for lib development
fi

[....]

#! /bin/ksh
# --------------------------------------------- main()
if [ "$DEVELOP" != "" ] ; then
     . /usr/local/lib/ksh/f_env
else
     . ~/lib/f_env
fi
[....]