To get the command line of a process without the ps command, and the PID of the command is known, use this command. This example is using a process with a PID of 3380.
[email protected]:~$ cat /proc/3380/cmdline /usr/lib/vmware/bin/thnuclnt-pdir/tmp/vmware-jason/thnuclnt-3346-fg
This will show the command line of the process without using the ps command. So blocking the ps command on a Linux system will not stop users from gaining information about the command-line switches used by a certain process.