Commands by hassylin (1)

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Console clock
A console clock with the current time.

list services running (as root)
A quick way to list services running

Getting GnuPG Public Keys From KeyServer
get my GPG-key from pgp.surfnet.nl, key id is 19886493.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Realtime apache hits per second
Change the cut range for hits per 10 sec, minute and so on... Grep can be used to filter on url or source IP.

Use Linux coding style in C program
put "-linux" option into $HOME/.indent.pro to make it default

Add a shadow to picture
Please take notice that if you are going to use an JPG file for shadow effect, let change -background none to -background white! Because -background none make a transparent effect while JPG doesn't support transparent! And when viewing, you will get a bacl box! So we will use an white background under! We can use other color as well!

how to export a table in .csv file
Exports the result of query in a csv file

Renaming a file without overwiting an existing file name
Sometimes in a hurry you may move or copy a file using an already existent file name. If you aliased the cp and mv command with the -i option you are prompted for a confirmation before overwriting but if your aliases aren't there you will loose the target file! The -b option will force the mv command to check if the destination file already exists and if it is already there a backup copy with an ending ~ is created.

Mapreduce style processing
parallel can be installed on your central node and can be used to run a command multiple times. In this example, multiple ssh connections are used to run commands. (-j is the number of jobs to run at the same time). The result can then be piped to commands to perform the "reduce" stage. (sort then uniq in this example). This example assumes "keyless ssh login" has been set up between the central node and all machines in the cluster. bashreduce may also do what you want.


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