Facets of Process Detail (Unix/Linux)

As a technology enthusiast and a middleware system administrator, over the years I observed many engineers working close to systems and noticed one peculiar feature about all of them, the all use ps and ls regardless of the reason they logged into the system, which is good. Talking more specifically about "ps", let me tell that it has come with variants from many technology groups over the two decades. The basic process detail command itself is not consistent over Unix and Linux implementations. Considering Solaris and RHEL as Ginny Pigs, 

Process Detail :  there are a lot of concerns regarding he listing of process detail over an operating system. For example, who can see the process details and who can not. Linux implementations (eg. RHEL) are not much fussy about this and they like to expose process details to all users. However, Solaris is a bit personality conscious, it makes sure that it shows the complete process details to either the user who owns the process or the "root".

• On a RHEL or any Linux implementation, ps -ef or ps auwwwx shows you all detail about every process currently running on that system.
• On Solaris systems, we use /usr/ucb/ps -auwwwx, to list the process details.

 However its almost rare that you want to know about all process running on that system, so you resolve to "grep-ing" of process detail, and most bluntly we sometimes use grep -v <username> or grep <username>, to filter out or filter in based on user name. To filter out the additional grep process which gets spawned as a result of grep activity happening in process command, people mostly resolve to ps -ef | grep <username> | grep -v grep. Now while using this you have almost always assume that your process detail wont contain the word "grep" and that is not always the case. I once faced an issue where my application JVM name was "grepall" and due to grep -v grep I was not getting that in the process listing. Regular expressions provide a much simpler way of doing that, for example if you want to grep for a particular user "abcd", something like this would help,

/usr/ucb/ps -auwwwx | grep [a]bcd. 

Rising above the politics of  ps, Unix and its variants have given us a wonderful command to deal with the issues we faced above. The "pgrep command" 

This command was specifically designed to perform intelligent grep over the process listing internally. So to just see a detail listing of process we use, 

pgrep -fl (full listing). 

However you have to remember, on Solaris, you to be either root or process owner to be able to see the full listing of process details.

To view the process details of a specific user, we use something like, 

pgrep -fl -u <username>.