• ps auxf: This displays a full listing of all processes on the system. The options used are:
  • a: Select all processes except both session leaders (see getsid(2)) and processes not associated with a terminal.
  • u: Display the process's user/owner
  • x: Show processes not attached to a terminal
  • f: Do full-format listing, showing the command line arguments
  • e: Select all processes. Identical to -A.

The ps command is a versatile tool in Linux for viewing information about running processes. Here's how you can use it to get details about process status:

Basic Usage:

By default, ps displays information about the processes associated with your current terminal session. It provides a limited set of columns:

$ ps
  PID TTY          TIME CMD
 18756 pts/0    00:00:00 bash
 20146 pts/0    00:00:00 ps

• PID (Process ID): Unique identifier for each process.
• TTY (Terminal): Terminal the process is associated with (e.g., pts/0).
• TIME: Total CPU time used by the process in hours:minutes:seconds format.
• CMD (Command): Name of the command that launched the process.

Getting More Information:

• -a (all processes): Lists all processes running on the system, including those of other users.
• -e (equivalent to -a): Lists all processes.
• -f (full format): Displays a more comprehensive set of information about each process, including:
  • USER: Username of the process owner.
  • %CPU: Percentage of CPU time the process is using.
  • %MEM: Percentage of memory the process is using.
  • VSZ: Virtual memory size of the process.
  • RSS: Resident Set Size (amount of physical memory used).
  • STAT: Process status (e.g., R - running, S - sleeping, Z - zombie).
  • START: Time the process started.
  • WCHAN: Event or resource the process is waiting for.
  • COMMAND: Full command line used to launch the process.

Examples:

# List all processes with full format
$ ps -f

# List processes owned by user "root"
$ ps -u root

# Filter processes by name (shows only the first matching process)
$ ps -C firefox

# Show processes with high CPU usage (use top or htop for a more interactive view)
$ ps -eo pid,%cpu --sort=-%cpu | head -5

Process Status Codes:

The STAT column in the full format output displays a single-character code indicating the process status. Here are some common codes:

• R: Running
• S: Sleeping (waiting for CPU)
• D: Uninterruptible sleep (waiting for I/O)
• T: Stopped (signal received)
• Z: Zombie (dead process, waiting for parent to collect)
• <: High-priority process

Further Exploration:

The ps command offers a wide range of options for filtering and formatting its output. Refer to the man ps command in your terminal for a complete list of options and their descriptions. Tools like top and htop provide a more interactive and visually appealing way to monitor processes in real-time.