Perl's file-test operators

The perlfunc documentation covers the long list of Perl's file-test operators that covers many situations you will encounter in practice.

Abstract:

-e: File exists.

-f: File is a plain file.

-d: File is a directory.

-z: File has zero size (is empty).

-s: File has nonzero size (returns size in bytes).

Details:

• -r
  File is readable by effective uid/gid.
• -w
  File is writable by effective uid/gid.
• -x
  File is executable by effective uid/gid.
• -o
  File is owned by effective uid.
• -R
  File is readable by real uid/gid.
• -W
  File is writable by real uid/gid.
• -X
  File is executable by real uid/gid.
• -O
  File is owned by real uid.
• -e
  File exists.
• -z
  File has zero size (is empty).
• -s
  File has nonzero size (returns size in bytes).
• -f
  File is a plain file.
• -d
  File is a directory.
• -l
  File is a symbolic link (false if symlinks aren’t supported by the file system).
• -p
  File is a named pipe (FIFO), or Filehandle is a pipe.
• -S
  File is a socket.
• -b
  File is a block special file.
• -c
  File is a character special file.
• -t
  Filehandle is opened to a tty.
• -u
  File has setuid bit set.
• -g
  File has setgid bit set.
• -k
  File has sticky bit set.
• -T
  File is an ASCII or UTF-8 text file (heuristic guess).
• -B
  File is a “binary” file (opposite of -T).
• -M
  Script start time minus file modification time, in days.
• -A
  Same for access time.
• -C
  Same for inode change time (Unix, may differ for other platforms)