How to check existence of the target in a makefile

Question

I want to run certain action in the shell depending on whether a default makefile in the current directory contains a certain target. ``` #!/bin/sh make -q some_target if test $? -le 1 ; then true # do something else false # do something else fi ``` This works, because GNU make returns error code 2 if the target is absent, 0 or 1 otherwise. The problem is that is not documented this way. Here is a slice of the man: ``` -q, --question ``Question mode''. Do not run any commands, or print anything; just return an exit status that is zero if the specified targets are already up to date, nonzero otherwise. ``` Only zero/nonzero is distinguished. What is the right way to do that?

Accepted Answer

You should read the GNU make manual rather than the man page: the man page is merely a summary not a complete definition. The manual says:

```
The exit status of make is always one of three values:

0    The exit status is zero if make is successful

2    The exit status is two if make encounters any errors. It will print messages
     describing the particular errors.

1    The exit status is one if you use the ‘-q’ flag and make determines that
     some target is not already up to date.
```

Since trying to create a target that doesn't exists is an error, you'll always get an exit code of 2 in that situation.

How to check existence of the target in a makefile

Solution

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