c:\test>perl -E"chop for 'fred'; print 'here' " Modification of a read-only value attempted at -e line 1. c:\test>perl -E"eval{ chop; } for 'fred'; print 'here' " here #### c:\test>perl -E"chop 'fred'; print 'here' " Can't modify constant item in chop at -e line 1, near "'fred';" Execution of -e aborted due to compilation errors. c:\test>perl -E"eval{ chop 'fred' }; print 'here' " Can't modify constant item in chop at -e line 1, near "'fred' }" Execution of -e aborted due to compilation errors.