Shell Programming and Scripting

 B149K, B456K, R4595, B569O, R56I9, B569I, R678K.

 /database/banking

/database/retailer

DB=$(expr substr $1 1 1)
case $DB in
'B') DIR=/database/banking
     ;;
'R') DIR=/database/retailer 
     ;;
*) echo error
   ;;

input=`echo $1 | cut -c1`
echo $cdir
if [[ $input = 'M']
then
cdir='/database/manufacturer'
else
cdir='/database/retailer'
fi

DB=$(expr substr $1 1 1)
case $DB in
'B') DIR=/database/banking
     ;;
'R') DIR=/database/retailer 
     ;;
*) echo error
   ;;

+ + expr substr M84934 1 1
DB=M
tj.sh[2]: syntax error at line 11 : `$DIR' unexpected

cat tj.sh
#!/bin/sh
DB=$(expr substr $1 1 1)
case $DB in
'B') DIR=/database/manufactuer
 ;;
 'R') DIR=/database/retailer
  ;;
   *) echo error
    ;;
echo $DIR

DB=$(expr substr $1 1 1)
case $DB in
'B') DIR=/database/manufactuer
 ;;
'R') DIR=/database/retailer
 ;;
*) echo error
 ;;
esac
 echo $DIR

cat dire.ksh
VAR=$1;
cdir=`awk -vvar=$VAR 'BEGIN{if(var ~ /^R/){print "/database/retailer"};if(var ~ /^B/){print "/database/manufcatuer"}}'`
echo $cdir

./dire.ksh R678K
/database/retailer

#!/bin/ksh
IAm=${0##*/}
case "$1" in
(B*)	DIR=/database/banking;;
(M*)	DIR=/database/manufacturer;;
(R*)	DIR=/database/retailer;;
(*)	printf '%s: database should start with "B", "M", or "R"\n' "$IAm" >&2
	printf 'Usage: %s database\n' "$IAm" >&2
	exit 1;;
esac
printf 'Using DIR="%s" for database="%s"\n' "$DIR" "$1"