Problem Statement
What is a PID in Linux?
Explanation
PID (Process ID) is a unique numerical identifier assigned to every running process in Linux. PIDs are assigned sequentially starting from 1, which is always the init or systemd process (the first process started by the kernel). When a process terminates, its PID can be reused for new processes.
Every process has a PID and a PPID (Parent Process ID) indicating which process created it. The ps command shows PIDs, and many system commands accept PIDs as arguments for operations like killing processes, changing priorities, or monitoring specific processes. Understanding PIDs is fundamental for process management.
You can find a process's PID using commands like ps aux | grep processname, pgrep processname, or pidof processname. The special file /proc/PID contains detailed information about each process. PIDs are essential for system administration, troubleshooting, and process control in Linux environments.
Practice Sets
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