- Some obscure Linux tips for the advanced Linux user
- Download a new kernel for your Ubuntu Linux machine
Some obscure Linux tips for the advanced Linux user
The magic SysRQ key combination is used to reset the Linux system if nothing else will work. To use this key combination, press: Alt+SysRQ then tap these keys in order: R, S, E, I, U, B. This will perform a safe re-boot of your Linux system assuming the Magic SysRQ keys are enabled in your Linux kernel.
The dstat utility for Linux replaces vmstat and iostat and provides a lot of information about your system with live statistics of CPU, network or disk usage.
Type sudo apt install dstat
to install this utility.
localhost% dstat -cglmnpry --total-cpu-usage-- ---paging-- ---load-avg--- ------memory-usage----- -net/total- ---procs--- --io/total- ---system-- usr sys idl wai stl| in out | 1m 5m 15m | used free buff cach| recv send|run blk new| read writ| int csw 7 1 82 10 0| 0 0 |0.53 0.43 0.50|2358M 7535M 287M 1489M| 0 0 | 0 0 1.8|60.4 7.27 |2603 6235 3 1 96 0 0| 0 0 |0.53 0.43 0.50|2359M 7534M 287M 1489M| 0 0 | 0 0 0| 0 0 |1823 5231 4 1 94 1 0| 0 0 |0.53 0.43 0.50|2359M 7534M 287M 1489M| 64B 64B| 0 0 1.0| 0 5.00 |1805 4915 3 1 96 0 0| 0 0 |0.53 0.43 0.50|2359M 7534M 287M 1489M| 0 0 | 0 0 0| 0 4.00 |1849 5036 4 1 95 0 0| 0 0 |0.53 0.43 0.50|2360M 7534M 287M 1489M| 303B 2018B| 0 0 0| 0 0 |1805 5029 4 1 95 0 0| 0 0 |0.49 0.42 0.49|2359M 7534M 287M 1489M| 847B 305B| 0 0 0| 0 0 |1818 5171 4 1 95 0 0| 0 0 |0.49 0.42 0.49|2360M 7534M 287M 1489M| 0 0 | 0 0 0| 0 0 |1816 5150 3 1 96 0 0| 0 0 |0.49 0.42 0.49|2360M 7534M 287M 1489M| 0 0 | 0 0 0| 0 0 |1764 4974 5 1 94 1 0| 0 0 |0.49 0.42 0.49|2360M 7534M 287M 1489M| 0 0 | 0 0 0| 0 27.0 |1929 5460 4 1 95 0 0| 0 0 |0.49 0.42 0.49|2360M 7534M 287M 1489M| 70B 70B| 0 0 0| 0 0 |1885 5660 4 1 95 0 0| 0 0 |0.53 0.43 0.50|2360M 7534M 287M 1489M| 70B 70B| 0 0 0| 0 0 |1838 5421 4 1 95 0 0| 0 0 |0.53 0.43 0.50|2360M 7533M 287M 1489M| 0 0 | 0 0 0| 0 0 |1877 5463 5 1 95 0 0| 0 0 |0.53 0.43 0.50|2360M 7533M 287M 1489M| 0 0 | 0 0 0| 0 0 |1857 5125 4 1 96 0 0| 0 0 |0.53 0.43 0.50|2360M 7533M 287M 1489M| 0 0 |1.0 0 0| 0 0 |1857 5391 4 1 95 0 0| 0 0 |0.53 0.43 0.50|2360M 7533M 287M 1489M| 0 0 |4.0 0 0| 0 0 |1797 5206 4 1 95 0 0| 0 0 |0.57 0.44 0.50|2360M 7533M 287M 1489M| 64B 64B| 0 0 0| 0 0 |1825 5107 4 1 95 1 0| 0 0 |0.57 0.44 0.50|2360M 7533M 287M 1489M| 0 0 | 0 0 0| 0 3.00 |1837 5276 3 1 96 0 0| 0 0 |0.57 0.44 0.50|2361M 7533M 287M 1489M| 0 0 | 0 0 0| 0 0 |1817 5351 4 1 95 0 0| 0 0 |0.57 0.44 0.50|2361M 7533M 287M 1489M| 0 0 | 0 0 0| 0 1.00 |1789 5010 4 1 95 0 0| 0 0 |0.57 0.44 0.50|2361M 7533M 287M 1489M| 326B 2081B| 0 0 0| 0 0 |1860 5399 4 1 95 0 0| 0 0 |0.60 0.45 0.50|2361M 7532M 287M 1489M| 961B 392B| 0 0 0| 0 0 |1904 5375 4 1 95 0 0| 0 0 |0.60 0.45 0.50|2361M 7532M 287M 1489M| 64B 0 | 0 0 0| 0 0 |1861 5391 4 1 95 0 0| 0 0 |0.60 0.45 0.50|2361M 7532M 287M 1489M| 0 0 | 0 0 0| 0 0 |1798 5395 4 1 95 1 0| 0 0 |0.60 0.45 0.50|2361M 7532M 287M 1489M| 0 0 | 0 0 0| 0 4.00 |1810 5123 |
To count lines of code in a C project file, install the cloc utility and execute it as as shown below.
sudo apt install cloc |
Then count the lines of code in a C file.
localhost% cloc ip.c 1 text file. 1 unique file. 0 files ignored. github.com/AlDanial/cloc v 1.70 T=0.03 s (32.7 files/s, 3400.8 lines/s) ------------------------------------------------------------------------------- Language files blank comment code ------------------------------------------------------------------------------- C 1 19 16 69 ------------------------------------------------------------------------------- |
The atop utility is another good tool for Linux, this shows comprehensive information about your Linux machine.
Type this command to install this.
sudo apt install atop |
Then run it to get very comprehensive information about a machine. Very cool.
The jnettop utility is a good way to monitor the network traffic on your Linux machine.
Use this command to install it.
[root@localhost ~]# dnf install jnettop |
The mtr command is a nice alternative to traceroute. This is used in this way.
[root@localhost ~]# mtr 8.8.8.8 |
Gives a nice output, showing the paths taken by the network packets.
If you wish to edit the last executed bash command in VI and then edit it, then use the fc command. This will open your last executed command in VI, you can edit it and then exit VI and the command will be executed. This could be very useful for a very long one-liner.
Use this command to list all applications using the Internet. The ss command is used to list socket statistics.
localhost% ss -p | grep http tcp ESTAB 0 0 192.168.100.2:43030 104.24.8.94:https users:(("firefox",pid=2235,fd=106)) tcp ESTAB 0 0 192.168.100.2:52418 157.240.8.18:https users:(("firefox",pid=2235,fd=113)) tcp ESTAB 0 0 192.168.100.2:60420 52.84.207.247:https users:(("firefox",pid=2235,fd=112)) tcp ESTAB 0 0 192.168.100.2:47754 122.149.3.18:https users:(("firefox",pid=2235,fd=88)) tcp ESTAB 0 0 192.168.100.2:46610 104.19.192.102:https users:(("firefox",pid=2235,fd=107)) tcp ESTAB 0 0 192.168.100.2:41736 157.240.8.23:https users:(("firefox",pid=2235,fd=111)) tcp ESTAB 0 0 192.168.100.2:51504 34.204.80.1:https users:(("firefox",pid=2235,fd=36)) tcp ESTAB 0 0 192.168.100.2:60416 52.84.207.247:https users:(("firefox",pid=2235,fd=109)) tcp ESTAB 0 0 192.168.100.2:47650 216.58.220.110:https users:(("firefox",pid=2235,fd=103)) tcp ESTAB 0 0 192.168.100.2:44382 35.160.19.195:https users:(("firefox",pid=2235,fd=81)) tcp ESTAB 0 0 192.168.100.2:34176 157.240.8.35:https users:(("firefox",pid=2235,fd=108)) tcp ESTAB 0 0 192.168.100.2:48774 172.217.25.174:https users:(("firefox",pid=2235,fd=51)) |
Very useful indeed.
Another way to cat a file from the command line.
localhost% dd if=pikachu.ascii bs=1 ▀▄ ▀▀▀▀ ▀▀▀▀▀ ▀▀▀▀▀▀ ▄▄▄▄▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▄▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄ ▄▀▀▀▀▀ ▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀▀▀▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀ 14990+0 records in 14990+0 records out 14990 bytes (15 kB, 15 KiB) copied, 0.0128079 s, 1.2 MB/s |
The dd command can be used to cat files, just use it this way and it works very well.
List your most popular Linux commands in your bash history.
ubuntu ~ $ cat .bash_history | cut -d ' ' -f1 | sort | uniq -c | sort -nr | head -20 413 sudo 170 ls 108 cd 101 cat 83 su 79 ps 73 mc 54 man 47 ifconfig 46 echo 35 john 26 vim 25 sipcalc 24 nmap 24 ip 17 grep 16 ping 16 gcc 16 curl 15 uptime |
Download a new kernel for your Ubuntu Linux machine
This website hosts kernel packages for the Ubuntu distribution with daily builds available.