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perl -pi -e 's/old_text/new_text/g' *.conf

This line replaces old_text with new_text in all the .conf files in the current folder. Of course you can use regular expressions.

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mysqlcheck -Aop -h hostname -u user -pPASSWORD

What all those mean:

–all-databases, -A; Check all tables in all databases. This is the same as using the –databases option and naming all the databases on the command line.
–optimize, -o Optimize the tables.
-h host to optimize (you can skip if it’s the localhost)
-u mysql user
-p the password

for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done

If you run slackware than all you really need is to create an empty file in /etc called forcefsck

You could do this by running:

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touch /etc/forcefsck

Other linux distributions might check for this file elsewhere, for example in the root directory so the command would be

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touch /forcefsck

Checking the documentation will always help.

So this would be a command to run in a folder filled with .wma files. This keeps the names but not the tags so be sure to use something like easytag to fill them after.

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for i in *.wma ; do mplayer -vo null -vc dummy -af resample=44100 -ao pcm:waveheader "$i" && lame -m j -h --vbr-new -b 320 audiodump.wav -o "`basename "$i" .wma`.mp3"; done; rm -f audiodump.wav

Here’s an easy way on how to do it:

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#!/bin/bash
# email send script example
#
# subject of email
SUBJECT="BASH SAYS HELLO"
# destination
EMAIL="user@yourdomain.com"
# Email body
EMAILMESSAGE="/tmp/messagebody.txt"
echo "Email sent from BASH" > $EMAILMESSAGE
echo "Another text line" >> $EMAILMESSAGE
# send message using /bin/mail
/bin/mail -s "$SUBJECT" "$EMAIL" < $EMAILMESSAGE

Easy.

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mysqldump -u user -ppassword your_database > database_backup.sql

Of course you need to replace:

• user – mysql username
• password – the password
• your_database – the database you want to backup

Adding -h host.domain.com would allow to backup a remote mysql database from YOUR shell, something like this:

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mysqldump -u user -h host.domain.com -ppassword your_database > database_backup.sql

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$ du -h --max-depth=1
3.2M    ./wp-admin
24M     ./wp-content
5.9M    ./wp-includes
4.0K    ./cgi-bin
44M     .

BTW the command above shows a typical WordPress installation. What I used was the switch -h which provides human readable sizes for folders (like Kilo, Giga, Tera, etc.) and I also used the swithc –max-depth to tell du only to go one folder deep otherwise it will also show the sizes of every subfolder from the current one down.

Should you like to have those results sorted it’s only a matter of piping the results of du into sort, like this:

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$ du -h --max-depth=1 | sort -nr
44M     .
24M     ./wp-content
5.9M    ./wp-includes
4.0K    ./cgi-bin
3.2M    ./wp-admin

What sort does is – surprise, sort it’s input. The switches used are -n to tell sort to sort by numerical values and -r to reverse the results (from big to small). Of course from here on you can pipe to text files, use even more complicated constructs but this should take care of the base.

If you managed to sort your folders how about sorting my wish list don’t forget to click a sponsor.