Perl Programming/Keywords/-S

The -S keyword

-S is a file test that tests, if the file is a socket.

It takes one argument, either a FILENAME, a FILEHANDLE, or a DIRHANDLE to test the associated file to see, if something is true about it. If the argument is omitted, it tests $_. -S returns 1 for true and an empty string for false. If the file doesn't exist or can't be examined, it returns undef and sets $! (errno).

Syntax

  -S DIRHANDLE
  -S EXPRESSION
  -S FILEHANDLE
  -S FILENAME
  -S