Positional arguments are passed as-is after the command name. Order matters.

cat file1.txt file2.txt

Options are named arguments and come in two forms:

• Short: One-letter options are preceeded by a - with values placed after (separated by a space).

  git commit -m "Fix"

• Long: Multi-letter options are preceeded by a -- with values placed after (separated by a = or a space).

  git commit --message="Fix" = git commit --message "Fix"

Note: Spaces aren't required after options, but are encouranged for readability, because git commit -m"Fix" looks cramped.

Flags don't take a value and can be long or short.

git commit --dry-run -v

When using multiple short flags, you can combine them into one.

ls -a -g -h = ls -agh

The order of options/flags does not matter.

ls -a -g = ls -g -a

However, some commands require all options/flags to come before positional arguments.

FAILS: ls my-dir -a
WORKS: ls -a my-dir

Thankfully, most modern commands are agnostic.

git add a.js -v = git add -v a.js

I prefer to put positional arguments before options/flags when possible, as I find it easier to read.

Quotes are only required for strings that contain special characters (e.g. spaces).

FAILS: git commit -m Fix thing
WORKS: git commit -m "Fix thing"
WORKS: git commit -m Fix

Note: When writing npm scripts, prefer double quotes " to single ' for better cross-compatability with Windows.

Many modern commands use a command-subcommand structure, like git. In the following example, git is the root command, and commit is the subcommand.

git commit -m "Hi"