try/finally syntax

[Superfox il Volpone]

I'm on perl v5.34.1, with the "try" feature enabled. I still cannot figure out the correct syntax for:

my $current_directory = getcwd();
try {
    chdir($working_directory);
} finally {
    chdir($current_directory);
};

This fails with the error:

syntax error at /script.pl line 56, near "} finally "
Execution of /script.pl aborted due to compilation errors.

```

[ikegami]

You have two errors that both result in that message:

• the catch clause is missing, and
• finally was only introduced in 5.36.

The syntax is

try BLOCK catch (VAR) BLOCK                # 5.34+
try BLOCK catch (VAR) BLOCK finally BLOCK  # 5.36+

And note that as a flow control statement, it isn't terminated by a semi-colon.

[Corion]

try/finally came only with Perl 5.36. Perl 5.34 only knows try/catch.

[ikegami]

That's only half of it.

$ perl -v | grep 'This is'
This is perl 5, version 40, subversion 0 (v5.40.0) built for x86_64-li
+nux-thread-multi

$ perl -e'use feature qw( try ); try { } finally { }'
try/catch/finally is experimental at -e line 1.
syntax error at -e line 1, near "} finally"
Execution of -e aborted due to compilation errors.

[eyepopslikeamosquito]

For more information on this topic see:

• New built-in perl5.38 try/catch syntax - a complete working example program using perl v5.38 built-in try/catch syntax
• Re: eval to replace die? (Exceptions and Error Handling References) - lots of references on exception handling in Perl

[eyepopslikeamosquito]

> I'm on perl v5.34.1, with the "try" feature enabled

From this 2015 PM node, I see (like me) you have a long-standing keen interest in Perl's try/catch exception handling. :-) That being the case, and assuming you're stuck using the system perl v5.34.1, why not simply leave that version of perl alone and build your own from the latest stable source release, namely perl v5.40.0?

In my experience, this is an easy and reliable chore to perform on Linux, as described in detail at:

• CPAN and Package Manager Security References - includes a detailed example of securely building perl v5.38.0 from source on Ubuntu
• Re: 5.40 released (perl new feature References) - describing changes in behaviour of perl's try/catch exception handling after building perl v5.40.0 from source