perl function setpriority

The setpriority function in Perl is used to set the priority of a process. The priority determines the amount of CPU time a process receives relative to other processes.

Here's an example of using setpriority in a script to set the priority of the current process:

# get the current process ID
my $pid = $$;

# get the current priority
my $priority = getpriority(0, $pid);

print "Current priority: $priority\n";

# set the new priority
setpriority(0, $pid, 10);

# get the new priority
$priority = getpriority(0, $pid);

print "New priority: $priority\n";

In this example, the $$ variable is used to get the current process ID, and the getpriority function is used to get the current priority of the process. These values are printed using print statements.

The setpriority function is then called to set the new priority of the process to 10. After calling setpriority, the getpriority function is called again to get the new priority of the process, which is printed using another print statement.

Note that the priority range is system-dependent, and may be different on different systems. Typically, the priority range is from -20 (highest priority) to 19 (lowest priority). The setpriority function can only be called by the process itself or by a privileged process such as root. If you try to call setpriority from an unprivileged process, you may get an error.