Bash else syntax error?

sick12301 · 04-13-2021, 10:48 AM

Hello,
I am trying to make a password script in bash.
However else throws a syntax error??

Code:

#!/bin/bash
read -p "Password for user 'sick12301': " -n 1 -r
if [[ $REPLY =~ ^[meisthebest]$ ]]
else logout
then
        echo "\nwelcome"
fi

shruggy · 04-13-2021, 10:53 AM

Wrong order: then must come first, else after that.

astrogeek · 04-13-2021, 11:54 AM

Welcome to LQ and the Programming forum!

As said already, the else clause must follow the then clause, including its list of operations to carry out. From man bash:

Code:

if list; then list; [ elif list; then list; ] ... [ else list; ] fi
              The if list is executed.  If its exit status is zero, the then  list  is  executed.   Otherwise,
              each  elif list is executed in turn, and if its exit status is zero, the corresponding then list
              is executed and the command completes.  Otherwise, the else list is executed, if  present.   The
              exit  status  is  the  exit  status of the last command executed, or zero if no condition tested
              true.

sick12301 · 04-13-2021, 04:08 PM

Quote:

Originally Posted by shruggy

Wrong order: then must come first, else after that.

Still not working

Code:

#!/bin/bash
read -p "Password for user 'sick12301': " -n 1 -r
if [[ $REPLY =~ ^[meisthebest]$ ]]
then
	echo "\nwelcome"
fi
else logout

EDIT: Nevermind I fixed I had to put else inside the if command.

Ser Olmy · 04-13-2021, 04:10 PM

Still wrong. You have a fi before the else.

grail · 04-13-2021, 09:08 PM

Also, while a matter of preference, having logout on the same line as else is cluttered and confusing. It would be cleaner to have logout on its own line

pan64 · 04-14-2021, 01:17 AM

I can only suggest you to use shellcheck to analyze your script.

tvc457 · 05-03-2021, 08:39 AM

Quote:

Originally Posted by grail

Also, while a matter of preference, having logout on the same line as else is cluttered and confusing. It would be cleaner to have logout on its own line

True, I agree
But there's a difference between a syntax error, and being hard to read

I see a "then" statement which is also on its own line - finally found somebody who actually does that, instead of using "; then"

GazL · 05-03-2021, 10:01 AM

I always use ; then, but in C I put my opening braces on a new line, BSD style. Which is odd now that I think about it.

tvc457 · 05-03-2021, 02:35 PM

Quote:

Originally Posted by GazL

I always use ; then, but in C I put my opening braces on a new line, BSD style. Which is odd now that I think about it.

Hmm yes - The usage of the semicolon should be a hint: it's a new command. New command, new line.

GazL · 05-03-2021, 02:59 PM

I suspect it stems from the fact that shell-scripts were commonly written on 24 line terminals and saving a line for each "if" helps with greater visibility of the code. It also mirrors K&R style C indentation, which is probably the one most folk use: though as I said, personally I prefer BSD style, or more specifically 'Allman'.