Basics of Command Line

The command line is a powerful tool which can shorten and simplify many tasks.

However, the command line requires some investment in learning. This page covers a few very basic ideas in using the command line.

• Lines preceeded with '#' are explanatory comments.
• The prefix “diglloyd:MPG lloyd$ ” is a prompt emitted by the command line; do not type this; your system will have something of the same form reflecting your own system names.
• Commands to type are shown in bold.

Very quick general tips for the command line

• Spaces matter; they are used as separators on the command line. Hence “Macintosh HD” is a nuisance name for a volume, as is any file name with spaces (enclose in straight quotes ""). Hence I name my boot volume “Boot”, which is also shorter and easier to type.
• Directory paths are separated by a forward slash "/".
• Case sensitive: Boot ≠ boot ≠ BOOT.
• The tab key will auto-complete filenames.
• There are a variety of special characters to be aware of, but the main useful one is the "*" character which can be used to wild card file names instead of typing them out (e.g. “ls *.jpg” to list all .jpg files).

Very brief examples of commands

The very, very basics.

Change directory

# change to home directory
diglloyd:MPG lloyd$ cd
# change to top level of the volume 'Master'
diglloyd:MPG lloyd$ cd /Volumes/Master
# change to top level of boot volume
diglloyd:MPG lloyd$ cd /
# change to Applications folder on boot volume
diglloyd:MPG lloyd$ cd /Applications

List files

# list files in current directory
diglloyd:MPG lloyd$ ls
# list files in current directory, recursively
diglloyd:MPG lloyd$ ls -lR
# list files in directory Photos on volume Master
diglloyd:MPG lloyd$ ls /Volumes/Master/Photos
# list all .jpg and .JPG files in current directory (wild card)
diglloyd:MPG lloyd$ ls *.jpg *.JPG

Run a command in the current directory

# run the command verifyVolumes.sh, found in the current directory
diglloyd:MPG lloyd$ ./VerifyVolumes.sh