$ perl -e '$result = `foobar`'

##</code><code>##

$ perl -Mstrict -Mwarnings -e '$result = `foobar`'
Global symbol "$result" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.

##</code><code>##

$ perl -Mstrict -Mwarnings -e 'my $result = `foobar`'
Can't exec "foobar": No such file or directory at -e line 1.

##</code><code>##

$ perl -Mstrict -Mwarnings -e 'my $result = `ls`'