The top command is a powerful real-time system monitoring tool in Linux. Understanding its various options allows for more precise control over how process information is displayed and updated. This guide details key command-line flags to customize your top experience.

Update Process Display Interval

Control how frequently the top command refreshes the displayed process information. This is crucial for observing system changes over specific time periods.

# To update every <interval> samples:
top -i <interval>

Set Update Delay

Specify the exact delay in seconds between each screen update. This allows for fine-tuning the refresh rate to match your monitoring needs.

# To set the delay between updates to <delay> seconds:
top -s <delay>

Manage Event Counting Mode

The top command can display event counts in different modes. Choose the mode that best suits your analysis of process activity.

Accumulative Mode

Event counts are cumulative.

# To set event counting to accumulative mode:
top -a

Delta Mode

Event counts represent the change since the last update.

# To set event counting to delta mode:
top -d

Absolute Mode

Event counts are displayed as absolute values.

# To set event counting to absolute mode:
top -e

Control Shared Library Statistics

Determine whether statistics for shared libraries (frameworks) are included in the process monitoring output.

Exclude Shared Libraries

Do not calculate statistics on shared libraries.

# To not calculate statistics on shared libraries, also known as frameworks:
top -F

Include Shared Libraries (Default)

Calculate statistics on shared libraries.

# To calculate statistics on shared libraries, also known as frameworks (default):
top -f

Display Command Line Usage and Exit

Access help information for the top command.

# To print command line usage information and exit:
top -h

Order Display by Sorting Key

Sort the process list based on a specified key in descending order. This is useful for quickly identifying the most resource-intensive processes.

# To order the display by sorting on <key> in descending order:
top -o <key>

By mastering these top command options, system administrators and developers can gain deeper insights into system performance and troubleshoot issues more effectively. For more advanced usage and other available options, consult the official Linux man pages for top.