Read a specific line from a file

Read a specific line from a file is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Some languages have special semantics for obtaining a known line number from a file. The task is to demonstrate how to obtain the contents of a specific line within a file. For the purpose of this task demonstrate how to the contents of the seventh line of a file can be obtained, and store this in a variable. If the file does not contain seven lines, or the seventh line is empty, or too big to be retrieved, output an appropriate message. If no special semantics are available for obtaining the required line, it is permissible to read line by line.