Files and File System

Everything is a file

A file is an addressable location that contains some data which can take many forms.

• Text data

• Binary/Image data

Files have associated meta-data

• Owner

• Group

• Timestamps

• Permission:

  1. Read(r)
  2. Write(w)
  3. Execute(x)
  4. no permission(-)

File permissions

File names

• Case-sensitive: myfile.txt is different from MyFile.txt.

• Hidden files: Filenames starting with a dot (.) are hidden by default.

• File extensions: Not mandatory, but using them helps identify file types.

• Spaces: Allowed but not recommended, use _ or – instead.

Best practices of file names

• Keep names descriptive and concise.

• Use lowercase for consistency.

• Avoid special characters unless necessary.

• Stick to alphanumeric characters, underscores, and hyphens.

File organization

Everything is mounted to the root directory

Files are referred to by their location called path

• Absolute Path (From the root): /cluster/tufts/mylab/user01

• Relative Path (From my current location)：user01

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