Commands using sort (800)

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make sure you don't add large file to your repository

easily find megabyte eating files or directories

Use md5sum to check your music and movie files. Also use diff.
This is a beginning script. You can create a file with > filename. You can also use diff to compare output run at different times to verify no change in your files. I apologize in advance if this is too simple. For some it should be a start.

Testing ftp server status
I must monitorize a couple of ftp servers every morning WITHOUT a port-scanner Instead of ftp'ing on 100 ftp servers manually to test their status I use this loop. It might be adaptable to other services, however it may require a 'logout' string instead of 'quit'. The file ftps.txt contains the full list of ftp servers to monitorize.

Short one line while loop that outputs parameterized content from one file to another
The above is an example of grabbing only the first column. You can define the start and end points specifically by chacater position using the following command: $ while read l; do echo ${l:10:40}; done < three-column-list.txt > column-c10-c40.txt Of course, it doesn't have to be a column, or extraction, it can be replacement $ while read l; do echo ${l/foo/bar}; done < list-with-foo.txt > list-with-bar.txt Read more about parameter expansion here: http://wiki.bash-hackers.org/syntax/pe Think of this as an alternative to awk or sed for file operations

list files recursively by size

To get you started!
Do it.

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"

generate random identicon

Tricky implementation of two-dimensional array in Bash.
Since Bash doesn't support two-dimensional arrays, you can limit your columns length by some big enough constant value ( in this example 100 ) and then index the array with i and j, or maybe write your own get() and set() methods to index the array properly like I implemented for example ( see Sample output ). For example for i=0 and j=0...99 you'll pick up one of 100 elements in the range [0,99] in the one-dimensional array. For i=1 and j=0...99 you'll pick up one of 100 elements in the range [100,199]. And so on. Be careful when using this, and remember that in fact you are always using one-dimensional array.


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