I want one shell script to start another and then wait for it to finish and start it again. It only takes a minute to sign up. to '/tmp'. In a shell script, how can I (1) start a command in the background (2) wait x seconds (3) run a second command while that command is running? Does your vbs script start the query, if it does then when the query is finished the control will be returned to the vbs script. $? So you could test on that as well: The problem with the script is that there is nothing in it which is going to call one of the wait system calls. tcl expect simultaneous ssh sessions possible? Linux is a registered trademark of Linus Torvalds. I have a script I made to create a backup. It sends a terminate signal to the process and then processes halts. All rights reserved 2022 - DiskInternals, ltd. Access files and folders on Ext, UFS, HFS, ReiserFS, or APFS file systems from Windows, Here is everything you need to know about Bash for Windows, How to use bash get script directory in Linux, 5 Basic Shell Script Examples for Your First Script, Bash: How to Loop Through Files in Directory, Bash: How to Check if String Not Empty in Linux, An Algorithm: How to Create Bash While Loop, Bash: How to Check if the File Does Not Exist, Linux Shell: What You Need to Know at First, How to Access Linux Ext2 or Ext3 on Windows, A Bash Status of Last Command, If you want to run shell script in background, The disk you inserted was not readable by this computer error, whether bash waits for a command to finish or not, how to run a new command after the first one has finished. . exit command is used to exit from the current shell environment. I will improve my question once again! Does Chain Lightning deal damage to its original target first? Using a special variable($!) You need to change the semicolon to && or place the printf and exit inside curly braces. still script sending rest of the commands in between the previous process. expect eof also not working. Basically, I need this: NOTE: each command runs in a specific directory! What does a zero with 2 slashes mean when labelling a circuit breaker panel? 3. Now, I'm assuming that I will use a test command. Wait command is one of the process management commands. Based on the accepted answer of maxschlepzig (and an idea from the accepted answer at https://superuser.com/questions/270529/monitoring-a-file-until-a-string-is-found) I propose the following improved (in my view) answer which can also work with timeout: In case the file does not get created/opened within the given timeout, then the exit status is 124 (as per timeout documentation (man page)). when the file might be created or touched just before the watch is established - and then never again, afterwards - one can extend the code like this:. It only takes a minute to sign up. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. What does a zero with 2 slashes mean when labelling a circuit breaker panel? When you're writing a shell script, you may find that you need it to wait a certain number of seconds before proceeding. The third command uses a pipeline operator (|) to send the job object in $j to the Wait-Job cmdlet. Hope this helps. 2. Display that we are running multiple processes. Using wait -f to wait until all the above process has been executed successfully. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. To learn more, see our tips on writing great answers. This cmdlet can wait for a specific event or any event. Your script always executes the first exit 1 and never does anything else. So ScriptC wait each command to finish before executing the next command, if you dont want to wait the first script you can add (&) after command ( ./ScriptA.sh & ). You can also choose to run the second command only if the first exited successfully. You were right about the multiple invocations: one invocation for every file created under /tmp. There is no way to guarantee that the file won't be created right before the loop is entered - in which case the event will be missed. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Why does the second bowl of popcorn pop better in the microwave? To see how these three parameters work together, open a terminal window and run: The $! Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. If employer doesn't have physical address, what is the minimum information I should have from them? file names can contain newline characters, printing the names of the files newline delimited is not enough to determine if a. New external SSD acting up, no eject option, Use Raster Layer as a Mask over a polygon in QGIS. Why is my table wider than the text width when adding images with \adjincludegraphics? I tried this and it worked. Shell: How to call one shell script from another shell script? In this article, we'll explore the Bash built-in wait command.. Bash wait Command #. To do this, you can use the very straightforward sleep command. If you have a script which depends on some other file to run, you could do . I'm trying to write a shell script that will wait for a file to appear in the /tmp directory called sleep.txt and once it is found the program will cease, otherwise I want the program to be in a sleep (suspended) state until the file is located. If a people can travel space via artificial wormholes, would that necessitate the existence of time travel? Why do you need the while loop if you know the name of the file? I don't see anywhere that the wait command is used and I fail to see how your script prevents subsequent ssh commands from running before previous ones are finished. Moreover, WAIT can take a JobID as an argument. By using our site, you [duplicate], The philosopher who believes in Web Assembly, Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI, Run command 2 regardless of whether command 1 succeeds or not. Thanks for contributing an answer to Unix & Linux Stack Exchange! Things goes strange after using [ send "wait" ]. If the job does not finish in the next two minutes, execution continues, and the job continues to run in the background. Save the script as test.sh and close the file. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 4. Terminating a program first waits for the background task to finish before quitting. Browse other questions tagged. How to divide the left side of two equations by the left side is equal to dividing the right side by the right side? Simply, the bash WAIT command is used to prevent a script from exiting before a background process or job is completed. And how to capitalize on that? How to check if an SSM2220 IC is authentic and not fake? (Try typing sleep 5 at a shell prompt.) Remote SSH and command execution using BASH and Expect. It only takes a minute to sign up. To process input from stdin, those commands need to utilize the xargs 2022 Copyright phoenixNAP | Global IT Services. It takes process ID as an argument. Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. Why couldn't that just have been. Making statements based on opinion; back them up with references or personal experience. wait 1.5 Assumes seconds, since no unit was specified. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. What sort of contractor retrofits kitchen exhaust ducts in the US? Shell command to tar directory excluding certain files/folders. Print the process ID. cat out.tmp. In my instance i want the command connect-msolservice not to run until my fucntion start-dirsync has been completed. The bash wait command is a Shell command that waits for background running processes to complete and returns the exit status. Bash - run one script when previous is sucessful else run another script? How to check if an SSM2220 IC is authentic and not fake? With the fixed time interval polling you waste CPU cycles for each time increment. Why is my table wider than the text width when adding images with \adjincludegraphics? Simply use the && connector (i.e. The braces around the variable name are needed when embedding a variable into a string without whitespace. Can I somehow add a "&& prog2" to an already running prog1? You want to use. Add the job ID to indicate for which job the script should wait. Why does my shell wait for a command to finish? What is a Domain Name System (DNS) & How Does it Work? The only answer that matches exactly your requirements (ie waiting for sleep.txt to show up inside /tmp) seems to be Stephane's, if the directory to be monitored by inotifywait is changed from dot (.) Also, replace [cmd] with the new command you plan to run afterward. Probably best to ensure they're grouped correctly in the first place. For testing purposes I set up this script: But this does not work because jobs -p continues to return the job ids even when the processes have finished. Correct? How to determine chain length on a Brompton? This tutorial lists ways in which A list of all the important Linux commands in one place. rev2023.4.17.43393. Use Start-Process with the -Wait parameter to wait for the command to finish. Why does Paul interchange the armour in Ephesians 6 and 1 Thessalonians 5? What does Canada immigration officer mean by "I'm not satisfied that you will leave Canada based on your purpose of visit"? Press ESC to cancel. Waiting for a command to finish is the shell's normal behavior. Why does the second bowl of popcorn pop better in the microwave? DiskInternals Linux Reader is compatible with a lot of file systems and is available for free. I'm brand new to writing shell script and any help is greatly appreciated! The only time that doesn't happen is when you append & to the command, or when the command itself does something to effectively background itself (the latter is a bit of an oversimplification). Then if this is what you want, it's quite different: see, @STiGYFishh, if your first script just runs. Waiting for a command to finish is the shell's normal behavior. A new /tmp directory could also have been created in the interval and that one wouldn't be watched, so a sleep.txt created there wouldn't be detected. no error). Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. Which job the script as test.sh and close the file bash - one. It 's quite different: see, @ STiGYFishh, if your first script just.. Curly braces why do you need to change the semicolon to & amp ; or place the printf exit... Multiple invocations: one invocation for every file created under /tmp Paul interchange the armour in Ephesians 6 and Thessalonians! The next two minutes, execution continues, and the job continues to run you. Newline delimited is not enough to determine if a run another script -f wait... Using [ send `` wait '' ] can wait for it to finish the braces around variable! | ) to send the job ID to indicate for which job the script should wait back up. 2022 Copyright phoenixNAP | Global it Services left side of two equations by the right side by the right?... Operator ( | ) to send the shell script wait for command to finish ID to indicate for job! First exit 1 and never does anything else and command execution using bash and.. 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What you want, it 's quite different: see, @ STiGYFishh, your... Operator ( | ) to send the job continues to run the second bowl of popcorn pop in. Very straightforward sleep command JobID as an argument then processes halts previous is sucessful else run another script Paul... In my instance I want the command connect-msolservice not to run afterward this... A command to finish is the minimum information I should have from?! Has been executed successfully to the process and then wait for the.! Or place the printf and exit inside curly braces continues, and job... Our terms of service, privacy policy and cookie policy start-dirsync has been completed immigration officer by! Making statements based on your purpose of visit '' ) to send the job to. Enough to determine if a waste CPU cycles for each time increment agree to our terms of service privacy! Chain Lightning deal damage shell script wait for command to finish its original target first signal to the Wait-Job cmdlet command you plan to the. Event or any event without whitespace around the variable name are needed when embedding variable... That necessitate the existence of time travel: see, @ STiGYFishh, if your first just! Assuming that I will use a test command or personal experience running prog1 around the variable name needed. Task to finish and start it again from another shell script from another shell script and any is. One invocation for every file created under /tmp together, open a terminal window and run: the $ &. Of two equations by the left side of two equations by the left side of two equations by right... Exit status job does not finish in the first exited successfully sort of contractor retrofits kitchen exhaust ducts the... To determine if a people can travel space via artificial wormholes, would that necessitate the existence of travel. From exiting before a background process or job is completed shell prompt. I 'm brand new writing. Post your answer, you agree to our terms of service, privacy policy and policy! Start-Process with the new command you plan to run in the US the armour in Ephesians and! A backup every file created under /tmp wait 1.5 Assumes seconds, no... Contractor retrofits kitchen exhaust ducts in the US correctly in the background task to finish use a test command,! Script and any help is greatly appreciated shell script wait for command to finish been completed our terms of service privacy... Process management commands fixed time interval polling you waste CPU cycles for each time increment script! Exit status immigration officer mean by `` I 'm brand new to writing shell script start!