Find sdx device/ATAx mappings

When dealing with hardware, you often see messages in the logs about disk issues or warnings.
Messages like:

 
ata9: hard resetting link
ata9: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
ata9.00: configured for UDMA/33
ata9: EH complete
 
 
ata3: SATA max UDMA/133 abar [email protected][......]

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Convert Squid/timestamps to a human readable format

Somebody had the brilliant idea to use Unix timestamps in the Squid log.
I suppose this makes it easy to parse, not so easy to read for us humans though!

This is an elegant and common way of solving this problem:

 
cat /var/log/squid/access.log | perl -p -e 's/^([0-9]*)/"[".localtime($1)."]"/e'[......]

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bash – remove first line with tail and last line with head

You can achieve the same result with other (more powerful) tools, but I like this approach because it's the simplest I can think of.

Let's say you have this text file called test.txt

 
line 1
line 2
line 3
 

Remove the first line

 
tail -n +2 test.txt
line 2
line 3
 

Remove the last l[......]

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sed – match and replace BIND/DNS serial number programmatically

I had to make some modifications to several BIND zone files, sed proved itself invaluable once again!

All the zone files looked something like this:

 
domain.com. IN SOA ns1.domain.com. postmaster.domain.com. (
               2015021001   ; Serial
               600          ; Refresh (10 minu[......]

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Remove all non-ascii characters with perl

Sometimes when creating one-liners, when the source is not "clean", you may end up with non-ascii characters which make the parsing harder.

To get rid of all of it, you can use perl.

 
cat dirty-source.txt|perl -pe 's/[^[:ascii:]]//g' > clean-output.txt
 

The same command can be used on a file[......]

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Converting spreadsheets to text files with ssconvert

ssconvert is a utility shipped with Gnumeric, and it's a command line spreadsheet converter.

Let's say that you have some data in a spreadsheet (eg spreadsheet.ods) and want to be able to easily parse it, and maybe use it in a script.

 
ssconvert -O 'separator=;' spreadsheet.ods parsable-data.tx[......]

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How to update all docker base images with one command

 
for docker in $(docker images|awk '{print $1,$2}'|sed 's/ /:/g'|grep -v REPOSITORY); do docker pull $docker; done
 

This command updates all your docker images but don't remove the old versions which have now been updated.

To do that, and clear some unnecessarily used space, you can run the[......]

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