When a dynamic library and program share functions

This is about making procps have a proper library but it really is a generic sort of question.  Say you are making a library and a program that uses that library.  Now at times you may have convience type functions; procps has them for things like escaping command names or allocation different sorts of memory.  Both the library and the programs use some of these functions.

Now, there seems only two approaches to this setup.  The first is to have the function stay in the library and for the program to call this function, just like all the other library functions.  But this means the library has exposed for all other programs that link to it and that doesn’t really make a lot of sense.

The second method is to have the functions defined in both places, perhaps in a file that is linked with the program and the library.  That seems to be duplicating the code in two different places.  Namespace collision could be a problem but that easily fixed with using some unqiue prefix.  I really don’t think having procfs_malloc, procfs_calloc and procfs_strdup are that useful.

I’m sure this sort of problem has been solved elsewhere.  Has anyone else come across this? The functions are simple utility type functions such as malloc a block of memory, if there is a problem print to stderr.

 

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procps-ng 3.3.1 released

Procps-ng, the Debian, Fedora and OpenSuSE fork of procps had another release today.  This is a bugfix release that fixes some important bugs that have cropped up in 3.3.0

pgrep crashes, pgrep -u not finding processes and a problem with top forest view have all been fixed.

An important addition to this release is that test scripts have now been added using the Dejagnu framework.  This framework tests most of the programs that ship with procps-ng.  There is only 100 tests so far and they are only tested for Linux architecture, but we expect to increase this test count and sophistication with each release.

The test scripts even found long-present but unknown bugs in the package. For example, running ps with output flags around the signal masks work as expected in Linux, but fail on kFreeBSD.  This is due to the unusual output of the relevant lines on that architecture. This is not a new bug, bug has been around for quite some time; noone ever noticed (or reported) it.

 

The Debian package has already been built and uploaded to the master FTP server.

Oh, and it is the first package with my new GPG key!

 

 

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New procps 3.3.0 for Debian

Coming soon after the upstream procps 3.3.0 being released, the Debian packages have been uploaded tonight.  The Debian packages have had the added benefit of being a day late by having a tiny 2 line patch to stop pgrep from crashing.

One regression that is on purpose, watch is currently not 8-bit clean again until I can sort out how to get the linking right with the new build process.

 

Testing Systems

The embarrassing problem with pgrep did start a discussion about testing, especially regression testing.  I’ve recently started using unit testing in my python programs and love the level of assurance those tests give me that I haven’t broken anything (to a degree anyhow). I’d really like to be able to type “make test” and have each of the programs run through a series of tests.

The problem with packages like procps (psmisc too) is that you really need to test the entire program, not just a stub, and that the program needs access to a know level of /proc.  The only thing I have seen that is even remotely what is needed is the bunch of scripts that coreutils uses which creates dummy files and directories to operate the commands on.  I expect we could do something similar with some scripts that create a known process but if anyone has a better idea about how to test a command line program let me know.

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procps-ng 3.3.0 Released

Tonight procps-ng, a fork of procps by developers from Debian, Fedora and SuSE was released.  The main goal of the team for this release was to reduce the number of patches we all carry in our respective distributions and learn from each other.  As an added bonus, we had one of the original authors of top, Jim, join the team and greatly enhance top.

While the upstream version is now released, the Debian package is not quite ready to go as it involves removing a lot of patches and adjusting some others.  The build system is also now a reasonably standard (but different to previous) setup that means the packing scripts need adjusting.

The best place to find out what is different is the procps NEWS file. The source code is available from Gitorious  at https://gitorious.org/procps

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