5.3 Empty Commands


An empty command is one that does nothing.

 header.h: ; 

Recall that the prerequisites list for a target can be followed by a semicolon and the command. Here a semicolon with nothing after it indicates that there are no commands. You could instead follow the target with a line containing only a tab, but that would be impossible to read. Empty commands are most often used to prevent a pattern rule from matching the target and executing commands you don't want.

Note that in other versions of make , empty targets are sometimes used as phony targets. In GNU make , use the .PHONY special target instead; it's safer and clearer.

Managing Projects with GNU make
Managing Projects with GNU Make (Nutshell Handbooks)
ISBN: 0596006101
EAN: 2147483647
Year: 2003
Pages: 131

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