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What does the sleep command do in Bash?
sleep is a command-line utility that allows you to suspends the calling process for a specified time. In other words, the sleep command pauses the execution of the next command for a given number of seconds. The sleep command is useful when used within a bash shell script, for example, when retrying a failed operation or inside a loop.
Is it possible to do a command without using sleep?
For example, performing the below command without actually using sleep: You have alternatives to sleep: They are at and cron. Contrary to sleep these need you to provide the time at which you need them to run. Make sure the atd service is running by executing service atd status.
What does the number mean in Linux sleep?
The NUMBER may be a positive integer or a floating-point number. The SUFFIX may be one of the following: When no suffix is specified, it defaults to seconds. When two or more arguments are given, the total amount of time is equivalent to the sum of their values.
How to set a delay in bash script?
You need to use the sleep command to add delay for a specified amount of time. The syntax is as follows for gnu/bash sleep command: s for seconds (the default) m for minutes.
How to pause a bash script in Linux?
When you run the script, it will print the current time in HH:MM:SS format. Then the sleep command pauses the script for 5 seconds. Once the specified time period elapses, the last line of the script prints the current time. The output will look something like this: Let’s take a look at a more advanced example:
What is the duration of the sleep command?
You can use more than one suffix and the duration of the sleep is the sum of all the suffix. For example, if you use the follow command: This will keep the script waiting for 1 hour, 10 minutes and 5 seconds. Note that the s suffix is still optional here.
How to sleep or delay a specified amount of time?
You need to use the sleep command to add delay for a specified amount of time. The syntax is as follows for gnu/bash sleep command: s for seconds (the default) m for minutes. h for hours. d for days. Please note that the sleep command in BSD family of operating systems (such as FreeBSD) or macOS/mac OS X does NOT take any suffix arguments (m/h/d).
Where do I find the sleep time in Linux?
Under recent Linux kernel, you will find a variables file named `/proc/timer_list` where you could read an `offset` and a `now` variable, in **nanoseconds**. So we may compute sleep time to reach the *very top* desired time.
Is there a way to sleep until a specific time?
You can calculate the number of seconds between now and the wake-up time and use the existing ‘sleep’ command. You could perhaps use ‘at’ to send a signal to your script, which sat waiting for that signal. I actually wrote https://tamentis.com/projects/sleepuntil/ for this exact purpose.