Normally make prints each command line before it is executed.
We call this echoing because it gives the appearance that you
are typing the commands yourself.
When a line starts with ‘@’, the echoing of that line is suppressed.
The ‘@’ is discarded before the command is passed to the shell.
Typically you would use this for a command whose only effect is to print
something, such as an echo command to indicate progress through
the makefile:
@echo About to make distribution files
When make is given the flag ‘-n’ or ‘--just-print’
it only echoes commands, it won't execute them. See Summary of Options. In this case and only this case, even the
commands starting with ‘@’ are printed. This flag is useful for
finding out which commands make thinks are necessary without
actually doing them.
The ‘-s’ or ‘--silent’
flag to make prevents all echoing, as if all commands
started with ‘@’. A rule in the makefile for the special target
.SILENT without prerequisites has the same effect
(see Special Built-in Target Names).
.SILENT is essentially obsolete since ‘@’ is more flexible.