Commands using perl (369)

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shell bash iterate number range with for loop

Reverse SSH
this command from the source server and this follow in the destination server: ssh user@localhost -p 8888

list files recursively by size

function to verify an IP address - can be used at the shell prompt or in a shell script
When processing IP addresses in the shell (or shell script) it is useful to be able to verify that the value of data is an IP address (an not some random string or non-sensible IP address).

Duplicate several drives concurrently
If you have some drive imaging to do, you can boot into any liveCD and use a commodity machine. The drives will be written in parallel. To improve efficiency, specify a larger block size in dd: $dd if=/dev/sda bs=64k | tee >(dd of=/dev/sdb bs=64k) | dd of=/dev/sdc bs=64k To image more drives , insert them as additional arguments to tee: $dd if=/dev/sda | tee >(dd of=/dev/sdb) >(dd of=/dev/sdc) >(dd of=/dev/sdd) | dd of=/dev/sde

Identify differences between directories (possibly on different servers)
This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.

list current ssh clients

Prints a file leaving out all blank lines and comment-only lines
Does not print any line that either: - is empty - contains only spaces or tabs - starts with # - starts with spaces/tabs followed by a #

Cleanup firefox's database.

Sort the size usage of a directory tree by gigabytes, kilobytes, megabytes, then bytes.
Probably only works with GNU du and modern perls.


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