Commands by wanker (1)

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shell function to underline a given string.
underline() will print $1, followed by a series of '=' characters the width of $1. An optional second argument can be used to replace '=' with a given character. This function is useful for breaking lots of data emitted in a for loop into sections which are easier to parse visually. Let's say that 'xxxx' is a very common pattern occurring in a group of CSV files. You could run $ grep xxxx *.csv This would print the name of each csv file before each matching line, but the output would be hard to parse visually. $ for i in *.csv; do printf "\n"; underline $i; grep "xxxx" $i; done Will break the output into sections separated by the name of the file, underlined.

Sysadmin day date of any given year
Calculate the date of Sysadmin day (last Friday of July) of any given year

reduce mp3 bitrate (and size, of course)
Useful if you have to put some mp3 files into mobile devices (ie mobile phones with no much memory)

Command to Show a List of Special Characters for bash prompt (PS1)
I use this command (PS1) to show a list bash prompt's special characters. I tested it against A flavor of Red Hat Linux and Mac OS X

Change newline to space in a file just using echo
Changing newline to spaces using just echo

Create a tar archive using 7z compression
Using 7z to create archives is OK, but when you use tar, you preserve all file-specific information such as ownership, perms, etc. If that's important to you, this is a better way to do it.

Remove space and/or tab characters at the end of line
The command removes all space and/or tabulation characters preceding new line

function to compute what percentage of X is Y? Where percent/100 = X/Y => percent=100*X/Y
This function make it easy to compute X/Y as a percentage. The name "wpoxiy" is an acronym of "what percentage of X is Y"

Get IP from hostname

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"


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