Ranking of the most frequently used commands

Lets take a quick look at how to get the most frequently used commands on you shell. So what we need to do is this:

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      history | awk '{print $2}' | awk 'BEGIN {FS="|"}{print $1}' | sort | uniq -c | sort -n | tail | sort -nr
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So, how did we arrive at this and will this always work? No it might not always work. A typical example is where HISTTIMEFORMAT variable is set. In that case, if you check history, you will see that after the number column we have time and date in the specified format, in which case, you will get wrong information from the above command. Anyways, forgetting these special cases, lets go to how we got this command:

bash mathematical calculators.

To start with , the most simple and easy to use should be “bc”. but just for some guys who want to be more experimental, here are few more bash calulator programs. These are completely command line and thus you can completely integrate them in your shell script or use them in shell script to do some really crazy maths calculations.

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      sudo yum install calc clac
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Lets start with installing these. Before we start, don’t blame and flame me if your favourite is not there in the list. If it is not, better is you drop me  a comment or email, and I will see, if I can include it in the list above, but remember this is only for console based calculators.

Linux humour – tar is coward

Some errors are too good and though you would have seen them couple of times you don’t realize until sometimes it just hits you, like the one below:

tar: Cowardly refusing to create an empty archive

Related articles

• Tar Tricks on Linux (descentintodarkness.wordpress.com)

perl is faster than bash in some cases.

Some days back, I had to generate some data to be uploaded to a database. As usual I assumed that bash should be faster and hence wrote the script to create the files in bash. But I found that even after 5 hours I was only 10% done with the data generation. Now that would mean that it would take around 50 hours to complete the data generation. Something did not look correct to me and I asked one of my colleague. He suggested I do a strace.

Shell Scripting

Here are some links for bash programming that you may find useful.

http://tips-linux.net/en/content/pro-bash-programming

http://tips-linux.net/en/content/expert-shell-scripting

http://tips-linux.net/en/content/beginning-linux-command-line

http://tips-linux.net/en/content/bash-pocket-reference

http://tips-linux.net/en/content/linux-command-line-and-shell-scripting-bible

Related articles

• Linux – Learning the Shell (edugeek.net)
• 10 Useful Tools, Websites And Tricks to Help You Master Linux Command (maketecheasier.com)
• lf-submit.sh – Bash mplayer Last.fm scrobbler (yjl.im)
• Linux command line tricks you need to know: IO redirection and piping (interstellr.com)
• imabonehead: Houcem HACHICHA’s Blog: My top ten shell/bash tricks! (houcemhachicha.blogspot.com)

Ultralight DIY distribution

Tiny Core: Ultralight DIY distribution

When reviewing a lightweight distribution, the term Swiss Army knife is sometimes employed to indicate that it’s packed with features despite a diminutive size. However, at 11MB for the ISO, Tiny Core is more of a blank-slate distribution, as when booted from a CDROM or a USB stick, it presents the user with a simple desktop consisting merely of a task launcher and a package manager. It contains some good ideas and it’s already perfectly usable, but I think it needs a few more refinements in order to become great. more»

write the output of a command to /var/log/user.log… each line will contain $USER, making this easy to grep for.

write the output of a command to /var/log/user.log… each line will contain $USER, making this easy to grep for.

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      &nbsp;log() { (echo "$ $@";$@) | logger -t $USER; }
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This command is useful if you want to copy the output of a series of commands to a file, for example if you want to pastebin the output from ‘uname -a’, ‘lspci -vvv’ and ‘lsmod’ for video driver trouble-shooting on your favorite Linux forum.