I have forked

$ man 2 fork

FORK(2)               Linux Programmer's Manual                 FORK(2)

NAME

fork - create a child process

SYNOPSIS

#include <unistd.h>

pid_t fork(void);

DESCRIPTION

fork()  creates  a  new process by  duplicating  the  calling  process.
The new process, referred to as the child, is an exact duplicate of the
calling process, referred to as the parent (...)

RETURN VALUE

On success, the PID of the child process is returned in the parent, and
0 is returned in the child. (...)

NOTES

Under  Linux,  fork()  is implemented using copy-on-write pages, so the
only penalty  that  it incurs is the time and memory required to dupli-
cate  the parent's page tables,  and  to create a unique task structure
for the child.