Usually at least one of those is present on any system
- top
- htop / another top variant
- ps
But sometimes the usual suspects are not available, especially in minimal containers.
But there is another, more low level, way that works: /proc
This is a virtual filesystem provided by the kernel about running processes.
So to mirror something like this:
$ ps aux |grep sleep
5 root 0:00 sleep 1000
21 root 0:00 sleep 10000000
36 root 0:00 grep sleep
We could do:
$ grep sleep /proc/*/cmdline
/proc/21/cmdline:sleep
/proc/5/cmdline:sleep
/proc/self/cmdline:sleep
/proc/thread-self/cmdline:sleep
The /proc file system is a pretty interesting thing to check out beyond this use as well!
- There is
exe, which links to the executed binary - Or
environ, which contains all environment variables of the process