$ pidof equinox
From the man page:
PIDOF(8) Linux System Administrator's Manual PIDOF(8)
NAME
pidof -- find the process ID of a running program.
SYNOPSIS
pidof [-s] [-c] [-x] [-o omitpid] [-o omitpid..] program [program..]
DESCRIPTION
Pidof finds the process id's (pids) of the named programs. It prints
those id's on the standard output. This program is on some systems used
in run-level change scripts, especially when the system has a System-V
like rc structure. In that case these scripts are located in
/etc/rc?.d, where ? is the runlevel. If the system has a start-stop-
daemon (8) program that should be used instead.
OPTIONS
-s Single shot - this instructs the program to only return one pid.
-c Only return process ids that are running with the same root
directory. This option is ignored for non-root users, as they
will be unable to check the current root directory of processes
they do not own.
-x Scripts too - this causes the program to also return process
id's of shells running the named scripts.
-o omitpid
Tells pidof to omit processes with that process id. The special
pid %PPID can be used to name the parent process of the pidof
program, in other words the calling shell or shell script.
EXIT STATUS
0 At least one program was found with the requested name.
1 No program was found with the requested name.