Commands by marcel (2)

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Query Wikipedia via console over DNS

Add a function you've defined to .bashrc
Example: To store the function addfunction after you have defined it: $ addfunction addfunction

which program is this port belongs to ?
Sometimes you need to use a port that is already opened by some program , and you don't know who to "kill" for it to release - so, now you do !

Test file system type before further commands execution
Exclude 400 client hosts with NFS auto-mounted home directories. Easily modified for inclusion in your scripts.

list block devices
Shows all block devices in a tree with descruptions of what they are.

Apache memory usage

rgrep: recursive grep without .svn
Only excludes .svn from filenames.

statistics in one line
In this example, file contains five columns where first column is text. Variance is calculated for columns 2 - 5 by using perl module Statistics::Descriptive. There are many more statistical functions available in the module.

Find the package that installed a command

Function that outputs dots every second until command completes
Very useful in shell scripts because you can run a task nicely in the background using job-control and output progress until it completes. Here's an example of how I use it in backup scripts to run gpg in the background to encrypt an archive file (which I create in this same way). $! is the process ID of the last run command, which is saved here as the variable PI, then sleeper is called with the process id of the gpg task (PI), and sleeper is also specified to output : instead of the default . every 3 seconds instead of the default 1. So a shorter version would be sleeper $!; The wait is also used here, though it may not be needed on your system. $ echo ">>> ENCRYPTING SQL BACKUP" $ gpg --output archive.tgz.asc --encrypt archive.tgz 1>/dev/null & $ PI=$!; sleeper $PI ":" 3; wait $PI && rm archive.tgz &>/dev/null Previously to get around the $! not always being available, I would instead check for the existance of the process ID by checking if the directory /proc/$PID existed, but not everyone uses proc anymore. That version is currently the one at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html but I plan on upgrading to this new version soon.


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