Commands by darkpand

Commands by darkpand (3)

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Clean your broken terminal

When some console full-screen program (minicom, vi, some installers) breaks down your terminal, try this command to revert all options to "sane" settings (sane is a built-in combo of a lot of stty options)
This is sample output - yours may be different.
16

stty sane

darkpand · 2009-11-09 15:58:06 39
IFS - use entire lines in your for cycles

When you use a "for" construct, it cycles on every word. If you want to cycle on a line-by-line basis (and, well, you can't use xargs -n1 :D), you can set the IFS variable to . Show Sample Output
This is sample output - yours may be different.
```
$ cat file
line one
line two
$ for i in `cat file`; do echo $i; done
line
one
line
two
$ export IFS=$(echo -e "\n")
$ for i in `cat file`; do echo $i; done
line one
line two
```
8

export IFS=$(echo -e "\n")

darkpand · 2009-07-09 15:25:37 9
c_rehash replacement

When you don't have c_rehash handy. Really simple - if you have a .pem file that doesn't really contain a x509 cert (let's say, newreq.pem), it will create a link, simply called '.0', pointing to that file.
This is sample output - yours may be different.
4

for file in *.pem; do ln -s $file `openssl x509 -hash -noout -in $file`.0; done

darkpand · 2009-06-30 17:42:07 104

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Get size of terminal

See the cols and lines and make sure the console it correctly configured for the screen size.

Block an IP address from connecting to a server

This appends (-A) a new rule to the INPUT chain, which specifies to drop all packets from a source (-s) IP address.

Open Port Check

also could specify port number: lsof -ni TCP:80

Forwards connections to your port 2000 to the port 22 of a remote host via ssh tunnel

Change user, assume environment, stay in current dir

I've used this a number of times troubleshooting user permissions. Instead of just 'su - user' you can throw another hyphen and stay in the original directory.

Display screen window number in prompt

Add this to your $HOME/.bashrc file. It will only set this prompt if it is running inside screen ($WINDOW var is set) Looks like this... $ ion@atomos:~[2]$

randomize hostname and mac address, force dhcp renew. (for anonymous networking)

this string of commands will release your dhcp address, change your mac address, generate a new random hostname and then get a new dhcp lease.

Rename a file with a random name

Give files a random name (don't ask why :-) The function will rename files but maintain their extensions. BUG: If a file doesn't have an extension it will end up with a dot at the end of the name. The parameter '8' for pwgen controls the length of filenames - eight random characters.

Verify/edit bash history command before executing it

Bash history commands are those that begin with the character ! (eg. the most popular 'sudo !!' Explained here => http://www.commandlinefu.com/commands/view/13). By default bash immediately executes the history command. Setting this shell option will make bash first allow you to verify/edit an history command before executing it. To set this option permanently, put this command in ~/.profile or ~/.bashrc file. To unset this option issue following command. $shopt -u histverify

Get the version of sshd on a remote system

I used this to confirm an upgrade to an SSH daemon was successful

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