Commands by xeor

Commands by xeor (15)

sorted by

find builtin in bash v4+

This command will give you the same list of files as "find /etc/ -name '*killall' | xargs ls -l". In a simpler format just do 'ls /etc/**/file'. It uses shell globbing, so it will also work with other commands, like "cp /etc/**/sshd sshd_backup". Show Sample Output
This is sample output - yours may be different.
```
[[email protected] ~]# ls -l /etc/**/*killall
-rwxr-xr-x. 1 root root 652 Apr 19 15:47 /etc/init.d/killall
lrwxrwxrwx. 1 root root  17 May 31 06:00 /etc/rc0.d/S00killall -> ../init.d/killall
lrwxrwxrwx. 1 root root  17 May 31 06:00 /etc/rc6.d/S00killall -> ../init.d/killall
```
9

ls -l /etc/**/*killall

xeor · 2011-08-30 05:57:49 0
Prepend a text to a file.

Using the sed -i (inline), you can replace the beginning of the first line of a file without redirecting the output to a temporary location.
This is sample output - yours may be different.
4

sed -i '1s/^/text to prepend\n/' file1

xeor · 2011-06-25 12:02:11 6

Using commandoutput as a file descriptor

Description is moved to "Sample output" because the html sanitizer for commandlinefu breaks the examples.. Show Sample Output

diff rpm_output_from_other_computer <(rpm -qa|sort)

xeor · 2011-06-25 11:45:15 0

Control ssh connection

SSH can be controlled trough an ~ escape sequence. Example, to terminate the current ssh connection, type a newline, then the ~ character, and last a . character. This is useful eg when an ssh connection hangs after you reboot a machine and the connection hangs. Show Sample Output
This is sample output - yours may be different.
```
Supported escape sequences:
  ~.  - terminate connection (and any multiplexed sessions)
  ~B  - send a BREAK to the remote system
  ~C  - open a command line
  ~R  - Request rekey (SSH protocol 2 only)
  ~^Z - suspend ssh
  ~#  - list forwarded connections
  ~&  - background ssh (when waiting for connections to terminate)
  ~?  - this message
  ~~  - send the escape character by typing it twice
(Note that escapes are only recognized immediately after newline.)
```
32

[enter]~?

xeor · 2011-06-17 18:29:59 3
Find out the starting directory of a script

I submitted a command like this without $0 if $BASH_SOURCE is unset. Therefor, it did only work when using ./script, not using 'sh script'. This version handles both, and will set $mydir in a script to the current working directory. It also works on linux, osx and probably bsd.
This is sample output - yours may be different.
0

mydir=$(cd $(dirname ${BASH_SOURCE:-$0});pwd)

xeor · 2011-04-27 16:33:38 0
Find out the starting directory of a script

I think this is the cleanest way of getting the current working directory of a script. It also works on osx, Linux, and probably bsd as well..
This is sample output - yours may be different.
-2

current_dir=$(cd $(dirname $BASH_SOURCE);pwd)

xeor · 2011-04-18 09:24:14 0
Automaticly cd into directory

Makes bash-4.x like zsh. Automatic cd into a directory if a command with that name doesnt exists. Ready for your ~/.bashrc file Show Sample Output
This is sample output - yours may be different.
```
~ $ shopt -s autocd
~ $ /var/log
/var/log $ 
/var/log $ apache
/var/log/apache $
```
1

shopt -s autocd

xeor · 2010-12-12 20:53:33 0
Close a hanging ssh session

~ is the ssh control character. If you type it after a newline, you can example force close the ssh session. , ~, then . If you want more info, type ~? when you are connecting using ssh. Very useful to kill of any hanging ssh sessions when nothing else works.
This is sample output - yours may be different.
22

~.

xeor · 2010-09-04 15:13:10 3
Smart `cd`.. cd to the file directory if you try to cd to a file

This little function will smarten 'cd'. If you try to cd into a file (which I guess we all have done), it cd's into the directory of that file instead. I had to use nesten if's, to get cd to still work with 'cd' (to get to $HOME), 'cd -' (to get to last directory), and 'cd foo\ bar'. Show Sample Output
This is sample output - yours may be different.
```
{ /root } # tail /var/log/messages
{ /root } # ... # ohh, I need to watch more logfiles
{ /root } # cd <alt+.> # to get last parameter
{ /var/log } # # Ready for action in the files folder
```
9

cd() { if [ -z "$1" ]; then command cd; else if [ -f "$1" ]; then command cd $(dirname "$1"); else command cd "$1"; fi; fi; }

xeor · 2010-04-23 19:17:43 4
Determine whether a CPU has 64 bit capability or not

Check if you have 64bit by looking for "lm" in cpuinfo. lm stands for "long mem". This can also be used without being root.
This is sample output - yours may be different.
4

if cat /proc/cpuinfo | grep " lm " &> /dev/null; then echo "Got 64bit" ; fi

xeor · 2010-04-10 15:31:58 3
Ping scanning without nmap

Not really an easier solution. But an example using && for (if last command returned 0). You can use || for (if last command returned other than 0).. Show Sample Output
This is sample output - yours may be different.
```
Answer from: 10.0.0.1
Answer from: 10.0.0.2
Answer from: 10.0.0.4
Answer from: 10.0.0.5
Answer from: 10.0.0.6
```
-2

prefix="10.0.0" && for i in `seq 25`; do ping -c 1 $prefix.$i &> /dev/null && echo "Answer from: $prefix.$i" ; done

xeor · 2010-04-07 17:17:21 1
Disconnect telnet

You are stuck with testing a tcp port using telnet, and must kill the telnet session from another terminal... Or, press ctrl+5 and write close/quit to force the current connection to close.. Show Sample Output
This is sample output - yours may be different.
```
# telnet somehost 1234
#   ^c^c^z^x
#   # Still connected...
```
2

telnet somehost 1234, <ctrl+5> close

xeor · 2010-04-05 12:10:21 1
Get your external IP address

For those of us that still uses lynx :)
This is sample output - yours may be different.
-5

lynx --dump http://ip.boa.nu|sed -e 's/^[[:space:]]*//' -e 's/*[[:space:]]$//'|grep -v ^$

xeor · 2009-11-04 22:23:45 0
Get your external IP address

Using our beloved wget
This is sample output - yours may be different.
-6

wget -O - -q ip.boa.nu

xeor · 2009-11-04 22:22:04 0
Check if a .no domain is available

Mostly for Norwegians, but easily adoptable to others. Very handy if you are brainstorming for a new domainname. Will only display the available ones.. You can usually do this better with dig, but if you dont have dig, or the TLD only have an online service to check with, this will be usefull.. Show Sample Output
This is sample output - yours may be different.
```
[email protected]:~$ check_dns_no test1 test2 test3
test2.no available
test3.no available
```
0

check_dns_no() { for i in $* ; do if `wget -O - -q http://www.norid.no/domenenavnbaser/whois/?query=$i.no | grep "no match" &>/dev/null` ; then echo $i.no "available" ; fi ; sleep 1 ;done }

xeor · 2009-09-30 21:17:33 2

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Display the output of a command from the first line until the first instance of a regular expression.

If BREs can be used, this sed version will also get the job done.

List only executables installed by a debian package

Safe for whitespaces in names.

View ~/.ssh/known_hosts key information

Will return the SSH server key information for each host you have in your ~/.ssh/known_hosts file, including key size, key fingerprint, key IP address or domain name, and key type.

Get AWS temporary credentials ready to export based on a MFA virtual appliance

You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Ask for a password, the passwd-style

You can ask repeatedly for a non-blank password using this function: function read_password() { while [ ! -n "$USER_PASSWORD" ]; do read -s -p"Password: " USER_PASSWORD if [ ! -n "$USER_PASSWORD" ]; then echo "ERROR: You must specify a valid password, please try again" fi echo done } Also you can set a time out (in seconds) to write the password read -t 10 -s -p"Password: " USER_PASSWORD_VARIABLE if [ ! $? -eq 0 ]; then echo "Time out!" fi

Find usb device in realtime

Using this command you can track a moment when usb device was attached.

An alarm clock using xmms2 and at

I like the order of the arguments better this way.

Serial console to a Vmware VM

Create a serial console with "socket (named pipe)" of "/tmp/socket", "from:server, to:virtual machine" in vmware player, etc.. gui. Run the above command after you have booted the guest OS (which should also be configured for serial console).

bulk rename files with sed, one-liner

Far from my favorite, but works in sh and with an old sed that doesn't support '-E'

Set a Reminder for yourself via the notification system

This will be seen through your system's visual notification system, notify-osd, notification-daemon, etc. --- sleep accepts s,m,h,d and floats (date; sleep .25m; date) --- notify-send (-t is in milliseconds && -u low / normal / critical) man notify-send for more information --- notification-daemon can use b/i/u/a HTML

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands by xeor

Commands by xeor (15) the last day the last week the last month all time sorted by date votes

What's this?

Check These Out

Stay in the loop…

Commands by xeor (15)

sorted by