tags: bash syntax case

```bash
case expression in
    pattern1 )
        statements ;;
    pattern2 )
        statements ;;
    ...
esac
```


# 1
Source: [thegeekstuff](https://www.thegeekstuff.com/2010/07/bash-case-statement/)
```bash
if [ $# -lt 2 ]
then
        echo "Usage : $0 Signalnumber PID"
        exit
fi

case "$1" in

1)  echo "Sending SIGHUP signal"
    kill -SIGHUP $2
    ;;
2)  echo  "Sending SIGINT signal"
    kill -SIGINT $2
    ;;
3)  echo  "Sending SIGQUIT signal"
    kill -SIGQUIT $2
    ;;
9) echo  "Sending SIGKILL signal"
   kill -SIGKILL $2
   ;;
*) echo "Signal number $1 is not processed"
   ;;
esac
```

```bash
# Count number of lines matches
-i) echo "Number of lines matches with the pattern $2 :"
    grep -c -i $2 $3
    ;;
# Count number of words matches
-c) echo "Number of words matches with the pattern $2 :"
    grep -o -i $2 $3 | wc -l
    ;;
# print all the matched lines
-p) echo "Lines matches with the pattern $2 :"
    grep -i $2 $3
    ;;
# Delete all the lines matches with the pattern
-d) echo "After deleting the lines matches with the pattern $2 :"
    sed -n "/$2/!p" $3
    ;;
*) echo "Invalid option"
   ;;
esac
```

```bash
for filename in $(ls)
do
	# Take extension available in a filename
        ext=${filename##*\.}
        case "$ext" in
        c) echo "$filename : C source file"
           ;;
        o) echo "$filename : Object file"
           ;;
        sh) echo "$filename : Shell script"
            ;;
        txt) echo "$filename : Text file"
             ;;
        *) echo " $filename : Not processed"
           ;;
esac
done
```

```bash
read yno
case $yno in

        [yY] | [yY][Ee][Ss] )
                echo "Agreed"
                ;;

        [nN] | [n|N][O|o] )
                echo "Not agreed, you can't proceed the installation";
                exit 1
                ;;
        *) echo "Invalid input"
            ;;
esac
```