A process is an instance of a computer program that is being executed.
A process is an instance of a running computer program.
Obtaining information about processes
Some useful tools
top
,htop
: text-mode system monitors, showing process information in real timelsof
: list process open files. Alsonetstat
specifically for network connections.ptrace()
: a programming interface to see all the system calls that a process is making. Different systems have different command line tools:strace
on Linux,ktrace
on *BSD,truss
on Solaris,dtrace
on FreeBSD and Mac OS X, …
Further reading
- What is using this network socket?
- How to find which processes are taking all the memory?
- Monitor one process
Keeping processes running
Some useful tools
- screen
screen
: run programs in a detachable terminal that you can reattach to later from a different place - cron
cron
: schedule a task at regular intervals. Alsoat
for a one-off.
Further reading
- Keep SSH Sessions running after disconnection.
- How can I pause up a running process over ssh, disown it, associate it to a new screen shell and unpause it?
- Running continuous jobs remotely.
- How can I close a terminal without killing the command running in it?