For security reason you may need to find out current working directory of a process. You can obtained this information by visiting /proc/pid/cwd directory or using the pwdx command. The pwdx command reports the current working directory of a process or processes.


Yesterday I wrote about increasing local port range with net.ipv4.ip_local_port_range proc file. There is also /proc/sys/kernel/pid_max file, which specifies the value at which PIDs wrap around (i.e., the value in this file is one greater than the maximum PID). The default value for this file, 32768, results in the same range of PIDs as on earlier kernels (<=2.4). The value in this file can be set to any value up to 2^22 (PID_MAX_LIMIT, approximately 4 million).


Chrooted jail allows run command or service such as http / mysql / postfix with special root directory i.e. chroot changes the root directory for application. The biggest benefit is a service that is re-rooted to another directory cannot access files outside that directory. Basically you are going to set service in sandbox. Chrooting offers […]


A question from my email bag:

How do changing run levels affect us or our users?