- Blank lines
Blank lines are ignored.
- Comment lines
A pound sign (
) can be used at the beginning of a line or anywhere in the middle.
ignores everything after the
- Dependency lines
Depending on one or more targets, certain commands that follow are executed. Possible formats include:
In the first form, subsequent commands are executed if the prerequisites are met. The second form is a variant that lets you specify the same targets on more than one dependency line. In both forms, if no prerequisites are supplied, subsequent commands are always executed (whenever any of the targets are specified). No tab should precede any targets
. (At the end of a dependency line, you can specify a command, preceded by a semicolon; however, commands are typically entered on their own lines, preceded by a tab.)
Targets of the form library
represent members of archive libraries, e.g.,
- Suffix rules
These specify that files ending with the first suffix can be prerequisites for files ending with the second suffix (assuming the root filenames are the same). Either of these formats can be used:
The second form means that the root filename depends on the filename with the corresponding suffix.
- Macro definitions
These have the following form:
Blank space is optional around the
- Include statements
Similar to the C include directive, these have the form:
processes the value of file
for macro expansions before attempting to open the file.
- Command lines
These lines are where you give the commands to actually rebuild those files that are out of date. Commands are grouped below the dependency line and are typed on lines that begin with a tab. If a command is preceded by a hyphen (-), make
ignores any error returned. If a command is preceded by an at sign (
), the command line won't echo on the display (unless make
is called with
). Further advice on command lines is given below.