How to write a bash script, if enter empty value "", or other value than 1 and 2 will not end the script, and will let user to renter 1 or 2. Basely if user type wrong, will let user to renter.
echo Press 1 for services and 2 for chkconfig?
echo -n "Please input yes or no: "
read ANS
if [ $ANS != "" ];
if [ $ANS == 1 ];
then
service vsftpd status
elif [ $ANS == 2 ];
then
service vsftpd status
else
echo please input 1 oe 2
fi
~
Try this:
while true
do
echo -n "Enter 1 for status, 2 for chkconfig, or q to quit: "
read ANS
if [ "$ANS" = q ]
then
break
elif [ "$ANS" = 1 ]
then
service vsftpd status
break
elif [ "$ANS" = 2 ]
then
service vsftpd chkconfig
break
else
echo "Invalid input. Try again."
fi
done
Notes:
To allow the use to reenter an answer if he failed to enter a proper answer the first time, the code is placed in a while loop. When a satisfactory answer is given, the break command is used to exit the loop. Lacking a satisfactory answer, the loop repeats until one is entered.
I added a "quit" option as this is something that users will generally insist on.
Inside [ style tests, the symbol for equality is =. Some shells will accept == here but others will choke on it. On the other hand, if [[ style tests are used (requires bash), then == is the correct symbol for equality.
In [ style tests, it is important to put shell variables in double-quotes. Thus, replace [ $ANS = 1 ] with [ "$ANS" = 1 ]. Otherwise, if the user type nothing but enter, then ANS would be empty and script would fail with an error. With [[ style tests, the quotes are not needed.
This will keep asking until you enter a "1" or a "2".
#!/bin/sh
while [ 1 ];
do
echo Please enter 1 or 2:
read ANS;
if [ "$ANS" = "1" ]; then echo You entered 1!; break; fi
if [ "$ANS" = "2" ]; then echo You entered 2!; break; fi
done
