Shell Programming and Scripting

Hi,

i want to list all system processes showing the attributes pid, user name, cpu consumption, and the difference between the resident memory and the swap memory needed to stock the process in case of suspending it.

i have two questions, the resident memory is the attribute size i think, but what attribute is the swap memory? vsize maybe?

And the 2nd question, if want to do the difference between those two values, is there a way to output this value on the same line as this command?

Code:

ps axo ppid,pcpu,priority,size,vsize,user

i want to convert size and vsize onto one attribute and show there the difference between those two. can i do that on that same line?

Thank you very much for your help, and once again sorry for my english i dont know if i explained myself correctly.

You could pipe your ps command through awk.

e.g.

Code:

ps ... | awk '{print $1 FS $2 FS $3 FS $5-$4 FS $6}'

Code:

ps ... | awk '{$4 = $5-$4; $5=""}1'

Code:

ps ... | awk '{$4 = $5-$4; $5=$6; NF=5}1'

Or something like that.

Or add an extra column with the new info:

Code:

ps ... | awk '{$5 = $5 FS $5-$4 FS}1'

Code:

PPID %CPU PRI SIZE VSZ 0  USER
0 0.0 20 0 10436 10436  root
1 0.0 20 0 28392 28392  Eskizoide
1 0.0 20 0 28392 28392  Eskizoide
2 0.0 20 0 43776 43776  Eskizoide
424 0.0 20 0 58672 58672  Eskizoide
49 0.0 20 0 46624 46624  Eskizoide
49 0.0 20 0 46180 46180  Eskizoide

Thats the output for what you said. I've used awk before but i dont know what thats suppose to do, i know you are doing the difference between $5 and $4 that are the attributes that we want to operate with, but what FS does? or that 1 at the end of the line?

Thanks for the reply.

FS is the (awk) field separator. In most cases, you could just replace that with a space (" "). Using FS is mostly only useful if you provide awk with a field separator to begin with (which is not the case here). The 1 at the end is a condition, which is always true, which performs an action. The default action is print. As no action is given, the 1 will just "print" the line.

This could be re-written as, for example:

Code:

ps ... | awk '{$5 = $5 FS $5-$4 FS; print}'

Or

Code:

ps ... | awk '{$5 = $5 FS $5-$4 FS}{print}'

So useful, thank you very much Scott, i think im staying here