Commands by adeverteuil (9)

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Restore mysql database uncompressing on the fly.
This way you keep the file compressed saving disk space. Other way less optimal using named pipes: mysql -uroot -p'passwd' database <

Search and Replace across multiple files
- grep for the word in a files, use recursion (to find files in sub directories), and list only file matches -| xargs passes the results from the grep command to sed -sed -i uses a regular expression (regex) to evaluate the change: s (search) / search word / target word / g (global replace)

sleep until X o'clock
pauses exactly long enough to wake at the top of the hour

List the size (in human readable form) of all sub folders from the current location
Simple and easy to remember. -h is human, -d1 = depth 1. disk usage, human, depth 1

Temporarily ignore known SSH hosts
you may create an alias also, which I did ;-) alias sshu="ssh -o UserKnownHostsFile=/dev/null "

Rename files in batch

Calculating series with awk: add numbers from 1 to 100
"seq 100" outputs 1,2,..,100, separated by newlines. awk adds them up and displays the sum. "seq 1 2 11" outputs 1,3,..,11. Variations: 1+3+...+(2n-1) = n^2 $ seq 1 2 19 | awk '{sum+=$1} END {print sum}' # displays 100 1/2 + 1/4 + ... = 1 $ seq 10 | awk '{sum+=1/(2**$1)} END {print sum}' # displays 0.999023

Monitor progress of a command
Pipe viewer is a terminal-based tool for monitoring the progress of data through a pipeline. It can be inserted into any normal pipeline between two processes to give a visual indication of how quickly data is passing through, how long it has taken, how near to completion it is, and an estimate of how long it will be until completion. Source: http://www.catonmat.net/blog/unix-utilities-pipe-viewer/

list files recursively by size

Limit the cpu usage of a process
Similar to `cpulimit`, although `prlimit` can be found shipped with recent util-linux. Example: limit CPU consumption to 10% for a math problem which ordinarily takes up 100% CPU: Before: $ bc -l


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