Some interesting and useful Linux tricks for using VIM and others.

There are a lot of very interesting tricks for using Linux. Number one.

How to get a bash shell prompt from VIM.

This is a command to use in command mode in VIM. If this is used in VIM running as root, say if it is in a sudo whitelist to edit a certain file, this will give a root prompt…

Another way to run a Linux executable. This is using systemd-run to run a program in user scope.

(jcartwright@2403-4800-25af-b00--2) 192.168.1.5 New LS  $ systemd-run --scope --user ls -hula
Running scope as unit: run-rcb03dcd532184139b0d9ea5041b7366a.scope
total 16K
drwxr-xr-x.  4 jcartwright jcartwright   46 May  3 06:46 .
drwxr-xr-x. 66 jcartwright jcartwright 8.0K May  3 07:48 ..
-rw-r--r--.  1 jcartwright jcartwright  752 Apr 23 09:33 Makefile
drwxr-xr-x.  2 jcartwright jcartwright   39 May  2 08:30 build
drwxr-xr-x.  2 jcartwright jcartwright   52 May  2 08:30 src

Run a copy of screen(1) as a normal user.

(jcartwright@2403-4800-25af-b00--2) 192.168.1.5 New LS  $ systemd-run --scope --user screen
Running scope as unit: run-rb0205c8327f24b1aac63cb2a8a8b8f83.scope

Get information on a Linux service using Systemd.

(jcartwright@2403-4800-25af-b00--2) 192.168.1.5 New LS  $ systemctl status httpd
● httpd.service - The Apache HTTP Server
     Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; preset: disabled)
    Drop-In: /usr/lib/systemd/system/httpd.service.d
             └─php-fpm.conf
     Active: active (running) since Fri 2024-05-03 06:41:47 AEST; 1h 46min ago
       Docs: man:httpd.service(8)
   Main PID: 1563 (httpd)
     Status: "Total requests: 0; Idle/Busy workers 100/0;Requests/sec: 0; Bytes served/sec:   0 B/sec"
      Tasks: 213 (limit: 100989)
     Memory: 46.4M
        CPU: 1.298s
     CGroup: /system.slice/httpd.service
             ├─1563 /usr/sbin/httpd -DFOREGROUND
             ├─1669 /usr/sbin/httpd -DFOREGROUND
             ├─1670 /usr/sbin/httpd -DFOREGROUND
             ├─1671 /usr/sbin/httpd -DFOREGROUND
             └─1672 /usr/sbin/httpd -DFOREGROUND

List the crontab for a Linux user.

(jcartwright@2403-4800-25af-b00--2) 192.168.1.5 /  $ crontab -l
15 10 * * * /home/jcartwright/Documents/test.sh

Type crontab -e to edit the crontab for a normal user.

15 10 * * * /home/jcartwright/Documents/test.sh
~                                                                                                                                                                                                                                                                                             
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~

This example cron job will run a script once a day at 10:15 AM.

Mar 27 10:15:02 localhost CROND[19735]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Mar 29 10:15:01 localhost CROND[14145]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Mar 29 10:15:01 localhost CROND[14142]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Mar 30 10:15:01 localhost CROND[15304]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Mar 30 10:15:01 localhost CROND[15301]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr  1 10:15:02 localhost CROND[22785]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr  1 10:15:02 localhost CROND[22782]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr  3 10:15:01 localhost CROND[19858]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr  3 10:15:01 localhost CROND[19853]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr  4 10:15:01 localhost CROND[14985]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr  4 10:15:01 localhost CROND[14982]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr  5 10:15:01 localhost CROND[8346]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr  5 10:15:01 localhost CROND[8343]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr  7 10:15:01 localhost CROND[10171]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr  7 10:15:02 localhost CROND[10168]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr  8 10:15:01 localhost CROND[36146]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr  8 10:15:02 localhost CROND[36143]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 10 10:15:01 localhost CROND[16254]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 10 10:15:01 localhost CROND[16251]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 11 10:15:02 localhost CROND[10245]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 11 10:15:02 localhost CROND[10242]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 12 10:15:01 localhost CROND[26465]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 12 10:15:01 localhost CROND[26462]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 17 10:15:01 localhost CROND[19171]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 17 10:15:01 localhost CROND[19168]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 23 10:15:02 localhost CROND[18556]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 23 10:15:02 localhost CROND[18553]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 24 10:15:01 localhost CROND[39546]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 24 10:15:01 localhost CROND[39543]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 25 10:15:01 localhost CROND[24449]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 25 10:15:01 localhost CROND[24446]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 26 10:15:01 localhost CROND[21254]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 26 10:15:01 localhost CROND[21251]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
Apr 29 10:15:01 localhost CROND[17679]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
Apr 29 10:15:01 localhost CROND[17676]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
May  1 10:15:01 localhost CROND[17711]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
May  1 10:15:01 localhost CROND[17705]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)
May  2 10:15:01 localhost CROND[22485]: (jcartwright) CMD (/home/jcartwright/Documents/test.sh)
May  2 10:15:01 localhost CROND[22482]: (jcartwright) CMDEND (/home/jcartwright/Documents/test.sh)

Check the /var/log/cron file to see if it worked. This is a good way to test a cron setup.

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