Notes About Interesting ps(1b) Behaviour

Apr 07, 2007 | 1 minute read
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Tags: Utility, Processus

I encounter a strange behavior using /usr/ucb/ps command recently. Normally, the COMMAND header of the output of the ps(1b) is truncated to the size of a default terminal. Adding one w flag can grow this output to 132 characters. Adding a second w flag doesn't truncate the output at all, reading the complete arguments list in the /proc/${PID}/as special file; in fact, a representation of the address space for the corresponding process. The restriction that apply here is the ability to read this file, generally the owner of the running process only.

Interestingly, at least on Solaris 8 and 9, you can print untruncated arguments list--even if you didn't have the the right to read the content of the address space special file--if the SUNWscpux package is installed. This package seems not delivered with Solaris 10.

As I remember, this package is a prerequisite for 64-bit architecture platform or you will see error messages such as Data Type Too Large if executed without it installed, but it seems to be able to behave in a very different manner as I expected.

Don't known what to think about this right now. Any though?