Description Vincent Rubiolo 2012-07-02 11:16:13 EDT

Build Identifier: 

When the TCF agent runs in daemon mode, its associated output is sent to the system logger. This becomes problematic when the user asks for logging to be enabled using the -L /path/to/log/file option. In this case, the agent will indeed enable logging but the user log file will remain empty.

The attached patch (on today's HEAD) fixes this with the following behavior:
1. The command line no more accepts both -d and -L options at the same time. An error message is shown instead.
2. The tracing infrastructure now also checks whether daemon mode is enabled to know when to output trace messages.

I am not sure whether point #2 above has performance issues (two tests instead of one). Other possible approaches :
a. setting log_name to '-' (stderr). This meant #defining a constant for the associated option (currently only open_log_file() knows about it).
b. setting log_file to stderr but this modifies the variable from another source file. It is indeed a global but I am not sure whether it is the best way to do it.

A limitation of the current patch is that since we cannot use -L w/ -d, the logging level has to be set by means of -l.

I welcome your guidance on these two aspects. I can submit another patch if needed.

In addition, I have modified the small agent help text (see #384049 for more info about it) to clearly state that messages are sent to the system logger when in daemon mode.

Reproducible: Always

Steps to Reproduce:
1. Clone the agent git repo and build it.
2. On a Unix system, run the agent in daemon mode with both '-d' and '-L foo' specified.
3. Note how 'foo' remains empty.