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proc

Introduction​

This cheat sheet provides a quick reference for some common proc filesystem commands and concepts. The proc filesystem is a special filesystem in Unix-like operating systems that provides information about processes and system information.

proc Concepts​

Viewing Process Information​

You can use the proc filesystem to view detailed information about running processes.

  • View process information for a specific process (replace PID with the process ID):

    cat /proc/PID/status

  • View the command-line arguments of a process (replace PID with the process ID):

    cat /proc/PID/cmdline

  • List all running processes:

    ps aux

System Information​

The proc filesystem also provides system-related information.

  • View CPU information:

    cat /proc/cpuinfo

  • View memory information:

    cat /proc/meminfo

Filesystem Structure​

The proc filesystem has a structured directory hierarchy.

  • Process information directory for a specific process (replace PID with the process ID):

    /proc/PID/

  • View the process ID of the current shell:

    echo $$

  • View the PID of the last background command:

    echo $!

Kernel Parameters​

You can modify kernel parameters through the proc filesystem.

  • View kernel parameters:

    cat /proc/sys/kernel/parameter_name

  • Modify a kernel parameter temporarily (requires root privileges):

    echo new_value > /proc/sys/kernel/parameter_name

proc Command-Line​

  • View process information for a specific process (replace PID with the process ID):

    cat /proc/PID/status

  • View the command-line arguments of a process (replace PID with the process ID):

    cat /proc/PID/cmdline

  • List all running processes:

    ps aux

  • View CPU information:

    cat /proc/cpuinfo

  • View memory information:

    cat /proc/meminfo

  • View kernel parameters:

    cat /proc/sys/kernel/parameter_name

  • Modify a kernel parameter temporarily (requires root privileges):

    echo new_value > /proc/sys/kernel/parameter_name

Conclusion​

This cheat sheet covers some common proc filesystem commands and concepts. The proc filesystem is a valuable resource for gathering information about running processes and system parameters, making it essential for system administrators and troubleshooting tasks; refer to the Linux proc documentation for more in-depth information and advanced usage.