ESM 263 Geographic Information Systems

Organizing your files (macOS)

QGIS stores its persistent information in macOS files. The macOS file system is organized into folders and files. (A folder is just a special kind of file in which macOS stashes information about other files or folders.) Together, folders and files implement a simple hierarchical information management system, which lets you group bags of information (files) into nested categories (folders).

NOTE: Frew may occasionally refer to a folder as a directory (what they’re called on Planet UNIX, where he grew up.) Don’t freak out; the terms are identical.

CONTENTS

• Organizing your files (macOS)
  • Pathnames
  • Current folder
  • Relative pathnames
  • ESM 263 pathname convention
  • Naming rule
  • For more information
  • P.S.:

Pathnames

The combination of one or more folder names and a file name is called a pathname. macOS pathnames are written as follows:

• First, the root folder: the mother of all folders, from which every file on your computer may be accessed.
  • a single /
• Then, zero or more folders:
  • folder name(s), separated by /
    • e.g. /Users/frew/Desktop/ESM263/HW1
• Finally, zero or one file:
  • file name, optionally followed by . and an extension
    • e.g. /Users/frew/Desktop/ESM263/HW1/CountryWatch.htm
  • The name and extension are usually referred to collectively as the filename.

Current folder

Any time you’re working on macOS, there’s a notion in effect called the current folder (AKA the working directory). For a macOS application, the current folder is usually the folder containing the document that it was started up with.

• For example, if you start QGIS by double-clicking on a map document (a file with a .qgs or .qgz extension), then QGIS’s current folder will be the folder containing the map document.
• When you first login to macOS, your working folder is set to your home folder. By default this is /Users/yourname, where yourname is your macOS username.

Relative pathnames

A pathname that doesn’t begin with the root folder is called a relative pathname. A relative pathname is assumed to have the pathname of the current folder prepended to it.

For example, if the current folder is /Users/frew/Desktop/ESM263, then HW1/CountryWatch.htm and /Users/frew/Desktop/ESM263/HW1/CountryWatch.htm both refer to the same file.

The special folder name .. (two periods) is often used in relative pathnames to refer to the parent folder of the current folder.

• For example, if the current folder is /Users/frew/Desktop/ESM263, then ../arf.txt and /Users/frew/Desktop/arf.txt both refer to the same file.

ESM 263 pathname convention

In the documentation for this course, we assume you have a folder on your computer named ESM263, and that all of the folders and files you use for the course will live in this folder (or one of its subfolders). When we refer to a pathname beginning with ESM263/, we’re referring to this folder.

• If you’re not sure where to put it, your desktop is a good choice, which would make its full pathnamne /Users/yourname/Desktop/ESM263

Naming rule

When working with QGIS, it’s essential that you follow this simple rule when naming files or folders:

Use only letters, numbers, and _ (underscores) in file or folder names.

• DON’T USE SPACES! Use underscores instead.
  • (QGIS is more forgiving than ArcGIS of spaces in pathnames, but “more” doesn’t mean “completely”…)

YOU’VE BEEN WARNED!

For more information

If you’d like even more detail on how filenames work (or don’t work), see:

• Sync isn’t working—troubleshoot issues with incompatible characters and bad filenames
  • Dropbox’s advice on making filenames portable across different operating systems

P.S.:

Did I mention:

DON’T USE SPACES IN PATHNAMES!