Killing a process means terminating the process or closing the process. There are mainly two commands used to kill a Process based on its Process ID or PID, the two commands are:<\/p>\n
- \n
- \u201ckill<\/strong>\u201d Command<\/li>\n
- \u201ckillall<\/strong>\u201d Command<\/li>\n<\/ul>\n
Both these commands have their method of killing a process which is explained below.<\/p>\n
Using SIGTERM vs. SIGKILL for Killing Process<\/strong><\/h2>\n
Processes can be killed either gracefully or forcefully. Two types of signals can be added to the command. One Signal is the SIGTERM and the other is the SIGKILL. The SIGTERM terminates a process gracefully whereas the SIGKILL terminates a process forcefully or immediately. In the SIGSTREAM, the process will save the data and then do a clean shutdown. In the SIGKILL, the process may or may not save the data and thus it should be avoided. SIGTERM uses the signal \u201c-15<\/strong>\u201d whereas SIGKILL uses the signal \u201c-9<\/strong>\u201d.<\/p>\n
See the Running Processes<\/strong><\/h3>\n
To see the list of running processes on your Ubuntu system, you can use the \u201cps -ef\u201d command:<\/p>\n
ps<\/span> -ef<\/span><\/div><\/div>\nThis will list all the processes with Process IDs that are currently running on your system:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-1.png\")
<\/p>\nKilling a Process in Ubuntu Using \u201ckill\u201d Command<\/strong><\/h3>\n
The \u201ckill\u201d command is used to kill a specific Process ID running on your Ubuntu System. To kill a Process ID with the \u201ckill\u201d command you can use the \u201ckill\u201d command with the Process ID mentioned:<\/p>\n
kill<\/span> <<\/span>pid><\/span><\/div><\/div>\nIn our case, if we want to kill a Process ID of the Firefox Web Application, we have to get the running process ID of Firefox first using the \u201cpidof\u201d Command. The \u201cpidof\u201d Command is used to list the running processes of a Specific Application. To display the process IDs of Firefox:<\/p>\n
pidof<\/span> firefox<\/div><\/div>\nAll the running Firefox Processes IDs will be displayed in the terminal:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-2.png\")
<\/p>\nTo Kill the Process ID or PID \u201c4469\u201d, use the \u201ckill\u201d command:<\/p>\n
kill<\/span> 4469<\/span><\/div><\/div>\n![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-3.png\")
<\/p>\nOnce killed, you can verify the process IDs using the \u201cpidof\u201d command which will list all the Process IDs again:<\/p>\n
pidof<\/span> firefox<\/div><\/div>\nYou will see the Process ID \u201c4469\u201d is killed by comparing previous process IDs with the new ones.<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-4.png\")
<\/p>\nKilling a Process in Ubuntu Using the \u201ckillall\u201d Command<\/strong><\/h3>\n
The \u201ckillall\u201d command will kill all of the processes that are currently run by an application. The \u201ckillall\u201d command is executed with the name of the Application you want to kill the process of. The syntax of \u201ckillall\u201d command is<\/p>\n
killall<\/span> <<\/span>application-name><\/span><\/div><\/div>\nConsidering our case where we want to kill all the processes of the Firefox browser. Before killing all the processes, use the \u201cpidof\u201d command to list the processes of Firefox:<\/p>\n
pidof<\/span> firefox<\/div><\/div>\nThis will display all the running processes of Firefox:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-5.png\")
<\/p>\nTo kill all processes of firefox, use the \u201ckillall\u201d command with the name of an application, in our case, Firefox:<\/p>\n
killall<\/span> firefox<\/div><\/div>\nThis will kill all the processes of Firefox and will close the application as well:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-6.png\")
<\/p>\nOnce the processes are killed, we use verify using the \u201cpidof\u201d Command again:<\/p>\n
pidof<\/span> firefox<\/div><\/div>\nAs no Process IDs are shown and the command line moves to the next line means all of the processes of Firefox are closed:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-7.png\")
<\/p>\nKilling a Process in Ubuntu Using SIGTERM<\/strong><\/h3>\n
The SIGTERM can be used with the \u201ckill\u201d command to kill the process in a more clean way. Before killing the process, the process saves the data of that process and performs a clean shutdown. The SIGTERM signal is used with the kill command:<\/p>\n
kill<\/span> -15<\/span> <<\/span>PID><\/span><\/div><\/div>\nConsidering our case, we have a Rhythmbox application opened in our Ubuntu system.<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-8.png\")
<\/p>\nTo check the process ID of Rhythymbox, use the \u201cpidof\u201d command:<\/p>\n
pidof<\/span> rhythmbox<\/div><\/div>\nThe rhythmbox has only one Process ID \u201c3135\u201d:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-9.png\")
<\/p>\nTo kill the process using SIGTERM, use the command:<\/p>\n
kill<\/span> -15<\/span> 3135<\/span><\/div><\/div>\nThis will kill the Process by waiting for the process to save data and then closing application:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-10.png\")
<\/p>\nTo verify, the \u201cpidof\u201d command can be used again:<\/p>\n
pidof<\/span> rhythmbox<\/div><\/div>\nThe Command Line moves to the next line without displaying the PID meaning the application is closed.<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-11.png\")
<\/p>\nKilling a Process in Ubuntu Using SIGKILL<\/strong><\/h3>\n
The SIGKILL can be used with the \u201ckill\u201d command to kill the process forcefully. The SIGKILL is usually avoided as before forcefully killing a process, the process may or may not save the data. The SIGKILL signal is used with the kill command:<\/p>\n
kill<\/span> -9<\/span> <<\/span>PID><\/span><\/div><\/div>\nConsidering our previous case where the Rhythmbox application was opened in our Ubuntu system:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-12.png\")
<\/p>\nTo list the process ID of Rhythmbox using the \u201cpidof\u201d Command:<\/p>\n
pidof<\/span> rhythmbox<\/div><\/div>\nThe Rhythmbox has a process ID \u201c3288\u201d:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-13.png\")
<\/p>\nTo kill this Process using the SIGKILL use the \u201ckill\u201d command with the SIGKILL Process Signal:<\/p>\n
kill<\/span> -9<\/span> 3288<\/span><\/div><\/div>\nThe Process will be closed forcefully and the application will close:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-14.png\")
<\/p>\nTo verify if the process was killed, use the \u201cpidof\u201d Command again:<\/p>\n
pidof<\/span> rhythmbox<\/div><\/div>\nThe command line will move to the next line without displaying the Process ID means the Process was killed using the Kill command:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-15.png\")
<\/p>\nKilling a Process in Ubuntu at a Specified Time<\/strong><\/h3>\n
The \u201ckill\u201d process can also kill a process that has been in execution for some time on Ubuntu. For instance, when killing a Process that has been in execution for more than 24 hours, use the command:<\/p>\n
killall<\/span> -o<\/span> 24h <<\/span>app-name><\/span><\/div><\/div>\nThe \u201c-o\u201d in the command specifies the processes to be killed. All the processes even those owned by other users will be killed. The \u201c24h\u201d is the Time Constraint. Consider our previous case where we have Firefox processes:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-16.png\")
<\/p>\nTo Kill the processes that have been running for more than 2 minutes, the \u201ckillall\u201d command can be used with the time mentioned in the command:<\/p>\n
killall<\/span> -o<\/span> 2m firefox<\/div><\/div>\nAs all the processes were running for more than 2 minutes, all the processes will be killed:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-17.png\")
<\/p>\nThe killed processes can be verified with the \u201cpidof\u201d command. The command line moves to the next line meaning none of the processes are running:<\/p>\n
![](\"http:\/\/linuxways.net\/wp-content\/uploads\/2023\/09\/word-image-21634-18.png\")
<\/p>\nSimilarly, instead of minutes, hours and seconds can also be mentioned.<\/p>\n
Conclusion<\/strong><\/h2>\n
To terminate a Process using its Process ID, the \u201ckill\u201d Command, as well as the \u201ckillall\u201d Command, can be used. The \u201ckill\u201d Command terminates one process at a time whereas the \u201ckillall\u201d command terminates all the processes of the application and closes it. In this article, we have covered both methods to terminate processes based on their Process IDs and we have also mentioned the SIGTERM vs. SIGKILL way of terminating a Process.<\/p>","protected":false},"excerpt":{"rendered":"
Kill a Process using the \u201ckill\u201d Command or the \u201ckillall\u201d Command. Terminate a single process using \u201ckill\u201d command or terminate all using the \u201ckillall\u201d command. <\/p>","protected":false},"author":110,"featured_media":21647,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1049,2],"tags":[],"class_list":["post-21634","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-linux-commands","category-ubuntu"],"_links":{"self":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/posts\/21634","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/users\/110"}],"replies":[{"embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/comments?post=21634"}],"version-history":[{"count":0,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/posts\/21634\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/media\/21647"}],"wp:attachment":[{"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/media?parent=21634"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/categories?post=21634"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/linuxways.net\/de\/wp-json\/wp\/v2\/tags?post=21634"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- \u201ckillall<\/strong>\u201d Command<\/li>\n<\/ul>\n