5 Writing the Commands in Rules

The commands of a rule consist of one or more shell command lines to be executed, one at a time, in the order they appear. Typically, the result of executing these commands is that the target of the rule is brought up to date.

Users use many different shell programs, but commands in makefiles are always interpreted by /bin/sh unless the makefile specifies otherwise. See Command Execution.

• Command Syntax: Command syntax features and pitfalls.
• Echoing: How to control when commands are echoed.
• Execution: How commands are executed.
• Parallel: How commands can be executed in parallel.
• Errors: What happens after a command execution error.
• Interrupts: What happens when a command is interrupted.
• Recursion: Invoking make from makefiles.
• Sequences: Defining canned sequences of commands.
• Empty Commands: Defining useful, do-nothing commands.