Commands by davidwhthomas (1)

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Extract rpm package name, version and release using some fancy sed regex
This command could seem pretty pointless especially when you can get the same result more easily using the rpm builtin queryformat, like: $ rpm -qa --qf "%{NAME} %{VERSION} %{RELEASE}.%{ARCH}\n" | sort | column -t but nonetheless I've learned that sometimes it can be quite interesting trying to explore alternative ways to accomplish the same task (as Perl folks like to say: There's more than one way to do it!)

password generator
make password randomly, default 8 chars, using bash3.X only, no external program.

grep for minus (-) sign
Use flag "--" to stop switch parsing

Shows a specific process memory usage

Capitalize first letter of each word in a string - A ruby alternative
"-n" loops around ; "-e" executes the given quoted string ; "$_" is the current line ; "split" creates an array on white space; each item of the array is "collected" to be then "capitalized" ; the array is "joined" back into a string.

Replace + Find

Backup your hard drive with dd
This will create an exact duplicate image of your hard drive that you can then restore by simply reversing the "if" & "of" locations. $ sudo dd if=/media/disk/backup/sda.backup of=/dev/sda Alternatively, you can use an SSH connection to do your backups: $dd if=/dev/sda | ssh user@ssh.server.com dd of=~/backup/sda.backup

calculate md5 sums for every file in a directory tree
an alternative

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Check every URL redirect (HTTP status codes 301/302) with curl

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