Re: generating helpful message when an invalid target specified

[Philip Guenther]

On Sat, Aug 18, 2012 at 11:31 AM, Rakesh Sharma <address@hidden> wrote:
> I am a new user of Make & my question is whether is it possible to generate a 
> help sort of a message,
> or maybe, have a help target in the makefile,  then when an invalid target is 
> specified, make should
> just run the "make help" target.

I don't know what you mean by "invalid target", but the .DEFAULT
target might be a step towards what you want.  To quote the info
pages:

`.DEFAULT'
     The recipe specified for `.DEFAULT' is used for any target for
     which no rules are found (either explicit rules or implicit rules).
     *Note Last Resort::.  If a `.DEFAULT' recipe is specified, every
     file mentioned as a prerequisite, but not as a target in a rule,
     will have that recipe executed on its behalf.  *Note Implicit Rule
     Search Algorithm: Implicit Rule Search.

The downside is that you'll need to list all valid prerequisites as
targets somewhere.


Philip Guenther