You can rename, or even delete a file while it is open, on Linux, *BSD, and similar OSes. That's one way to create a temporary anonymous file, which will disappear as soon as your open handle to it closes. It is caused by the strong dissociation between file name and file contents. Hard links are another example, where you can have two independent and completely fully qualified (no limits) paths to the same file contents.

Also, if on those platforms, you attempted to rename a log file for for example Apache while it is running, you'll see it doesn't stop it from still growing.

Windows won't allow you to rename or delete the file while its open, that's true.

In reply to Re^2: How to detect if file is in use? by bart
in thread How to detect if file is in use? by blazar

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.