Shell Programming and Scripting

function logm
{
echo inside logm
#OPTSTRING=":tTdDiIwWeEfFoO"
#while getopts ${OPTSTRING} opt
while getopts ":tTdDiIwWeEfFoO" opt
        do
echo OPTIND=${OPTIND}
echo OPTARG=${OPTARG}
echo opt=$opt
echo 1=$1
echo 2=$2
echo 3=$3
echo 4=$4
                case ${opt} in
                        t|T)
                          echo log TRACE ${2}
                          log TRACE ${2}
                          ;;
                        d)
                          echo log DEBUG ${2}
                          log DEBUG ${2}
                          ;;
                        D)
                          echo log DEBUG ${2}
                          log DEBUG ${2}
                          ;;
                        i|I)
                          echo log INFO ${2}
                          log INFO ${2}
                          ;;
                        w|W)
                          echo log WARN ${2}
                          log WARN ${2}
                          ;;
                        e|E)
                          echo log ERROR ${2}
                          log ERROR ${2}
                          ;;
                        f|F)
                          echo log FATAL ${2}
                          log FATAL ${2}
                          ;;
                        o|O)
                          echo log OFF ${2}
                          log OFF ${2}
                          ;;
                        *)
                         echo unknown opt $opt
                         ;;
                esac
        done
unset OPTSTRING
unset OPTIND
}

logm -TDIWEFO "this is the tdiwefo message"

inside logm
OPTIND=1
OPTARG=
opt=T
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
log TRACE this is the tdiwefo message
OPTIND=1
OPTARG=
opt=_D
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
unknown opt _D
OPTIND=1
OPTARG=
opt=_I
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
unknown opt _I
OPTIND=1
OPTARG=
opt=_W
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
unknown opt _W
OPTIND=1
OPTARG=
opt=_E
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
unknown opt _E
OPTIND=1
OPTARG=
opt=_F
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
unknown opt _F
OPTIND=2
OPTARG=
opt=_O
1=-TDIWEFO
2=this is the tdiwefo message
3=
4=
unknown opt _O

We need to introduce a parameter to contain the message. For example "m".

while getopts ":tTdDiIwWeEfFoOm:M:" opt

And in the case statement

m|M)
       MESSAGE_TEXT="${OPTARG}"
       ;;

We can then call the script as:

logm -TDIWEFO -m "this is the tdiwefo message"

function logm
{
for mc in $(some_command_to_separate $1 into letters)
do
  log $mc $2
done
}