function::udelay - Linux


udelay is a handy command that allows you to introduce a delay in microseconds in a Linux terminal. This functionality is commonly used for testing and debugging purposes, especially when it comes to optimizing the performance of scripts or specific processes.




  • -h, –help: Displays detailed help and usage information for the command.


  • Simple delay: Introduce a 100 microsecond delay.

    udelay 100
  • Delay with variable: Use a variable to specify the delay duration.

    udelay $DELAY
  • Nested delays: Create multiple nested delays for finer control.

    udelay 500
    udelay 200
    udelay 100

Common Issues

Incorrect input: Ensure that you specify the delay duration in microseconds. Other units (e.g., milliseconds) are not supported.

Timing accuracy: The actual delay duration may slightly vary depending on system load and hardware capabilities.


Combining with other commands: udelay can be integrated with other commands using piping or command substitution. For example, to pause a process for a specified duration:

echo "Pause for 100 microseconds..."
udelay 100

Automating delays: Use udelay in shell scripts to automate tasks that require precise timing. This is useful for optimizing performance or simulating user interactions.

Related Commands

  • sleep: Provides a more versatile way to introduce delays in seconds.
  • usleep: Similar to udelay but with a finer resolution in terms of delay duration (in microseconds).