Linux /proc Directory

The /proc directory in Linux is a special virtual file system that provides a mechanism for the kernel to send information to processes. Below is a detailed explanation of its components and uses.

1. /proc

Description:

• The /proc directory is a virtual file system that does not contain real files but rather system and process information.
• It treats everything as a file, making it easy to interact with system data.

2. ls -l /proc

Description:

• Since /proc is a file system, you can query it like any other directory.
• Each directory within /proc corresponds to a process ID (PID).
• Example command: ls -l /proc

3. Linux Utilities That Translate to Commands

Description:

• Many Linux utilities read from the /proc directory to gather system information.lsmod reads from /proc/moduleslsusb reads from /sys/devices/*lspci reads from /proc/bus/pci/*lsblk reads from /proc/partitions

4. <pid>

Description:

• Directories named after PIDs contain information about each running process./proc/<pid>/cmdline: Command line arguments for the process./proc/<pid>/environ: Environment variables visible to the process./proc/<pid>/fd: File descriptors used by the process./proc/<pid>/exe: Executable of the process./proc/<pid>/stat: Process status.

5. <pid>/task/<tid>

Description:

• Provides information about threads of a specific process./proc/<pid>/task/<tid>/comm: Command line variable linked to the thread./proc/<pid>/task/<tid>/children: List of child tasks of this task.

6. What Is It Used For?

Description:

• The /proc directory is used to add runtime functionality to the kernel, provide an interface to kernel data structures, and build custom process management tools.

Understanding the /proc directory is essential for effective Linux system administration and process management.