$ Linux Command

Processes

htop

Display an interactive process viewer.

processmonitorsignal

Additional Notes

htop is an interactive process viewer. It shows CPU, memory, swap, load, process state, users, command lines, and sortable process columns in a terminal UI.

Use htop when top is too cramped or when you want to search, sort, inspect process trees, change priority, or send signals interactively.

Syntax

htop [options]

Parameters

  • options: Startup filters and display settings.
  • pid: Optional process ID filter when supported by your version.
  • user: Optional user filter when supported by your version.

Common Options

  • -u USER, --user=USER: Show processes for one user.
  • -p PID, --pid=PID: Show only selected process IDs.
  • -d TENTHS, --delay=TENTHS: Set refresh delay in tenths of a second.
  • -s COLUMN, --sort-key=COLUMN: Sort by a column at startup.
  • -t, --tree: Show process tree view.
  • --readonly: Disable actions that change process state when supported.

Examples

htop

Open the interactive process viewer.

htop -u www-data

Show processes owned by www-data.

htop -p 1234

Focus on a specific process ID.

htop -t

Start in tree mode.

Interactive Keys

  • F3: Search processes.
  • F4: Filter visible processes.
  • F5: Toggle tree view.
  • F6: Choose sort column.
  • F9: Send a signal to the selected process.
  • F10: Quit.

Practical Notes

  • Installing htop may require a package manager because it is not always installed by default.
  • Use signal actions carefully on production systems.
  • For scripted process output, use ps, pgrep, or top -b instead of htop.