# ------------------------------------------------------------------------------
# f_CheckConnectivity                          checking connectivity for a host
# ------------------------------------------------------------------------------
# Author.....: Wolf Machowitsch
# last update: 2016 01 25    by: Wolf Machowitsch
# ------------------------------------------------------------------------------
# Revision Log:
# - 0.99   2007 01 18   Original Creation
#                       -
#
# - 1.00   2015 04 28   Production Version
#                       removed unecessary subshells
#
# - 1.01   2016 01 25   bugfix
#                       - changed ssh-call to cover for new hosts:
#                         added "-o 'CheckHostIP=no'"
#                         added "-o 'StrictHostKeyChecking=no'"
#
# ------------------------------------------------------------------------------
# Usage:
#     f_CheckConnectivity  char Hostname [ char user ]
#     checks the connectivity for the host given in $1 optionally using a
#     username given in $2. If no user name is given the current user is
#     assumed.
#
#     Example:  f_CheckConnectivity $host    # checks if $host can be worked on
#                                            # using the current user (usually
#                                            # this will be root)
#
# Prerequisites:
# -   to use this function, the FPATH variable must be set
#
# ------------------------------------------------------------------------------
# Documentation:
#     f_CheckConnectivity() checks in a successive manner. First an (IP)-ping
#     is issued. If this is successful a connection test is done by issuing
#     a command via ssh. f_CheckConnectivity() does NOT try to correct any
#     errors, merely stating them.
#
#     Parameters: char Host
#
#     returns:    0: connectivity test passed
#                 1: no ssh connection
#                 2: no IP connection
#                 3: parameter/other/internal error
#
# ------------------------------------------------------------------------------
# known bugs:
#
#     none
# ------------------------------------------------------------------------------
# .....................(C) 2007 Wolf Machowitsch ...............................
# ------------------------------------------------------------------------------

f_CheckConnectivity ()
{

$chFullDebug
                                                 # internal variables
typeset -i iRetVal=0                             # return value (see docu)
typeset    chHost="$1"                           # hostname
typeset    chUser="$2"                           # optional username

if [ -z "$1" ] ; then                            # check for prereqs
     iRetVal=3
elif [ "$chUser" == "" ] ; then
     chUser="$(who am i | cut -d' ' -f1)"
fi

if [ $iRetVal -eq 0 ] ; then
     if ! ping -c1 $chHost 1>/dev/null 2>&1 ; then
          iRetVal=2
     fi
fi
if [ $iRetVal -eq 0 ] ; then
     if ! ssh -nq                  \
              -o 'BatchMode=yes'   \
              -o 'CheckHostIP=no'  \
              -o 'StrictHostKeyChecking=no' \
                 ${chUser}@${chHost} date 1>/dev/null 2>&1; then
          iRetVal=1
     fi
fi

return $iRetVal

}
# --- EOF f_CheckConnectivity