Various filesystem-related functionality available in the core modules:

filename parsing/munging

• File::Spec
• File::Spec::Functions — better variant of above
• Cwd
• File::Basename

modify files / directories

• File::Copy
• File::Path

file contents, read-only

• File::Compare

exploring directories

• File::Find
• File::DosGlob

other

• File::Temp
• POSIX
  • creat() — create a new file
  • getcwd() — get the current working directory
  • lchown() — like chown(), but changes the owner of a symbolic link
  • mkfifo() — makes a FIFO special file
  • pathconf() — retrieve the value of a configurable limit on a file or directory
  • pipe() — create an interprocess channel