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Functions

Commands by root from sorted by
Terminal - Commands by root - 53 results
iptables -A INPUT -s 222.35.138.25/32 -j DROP
2009-02-02 12:42:04
User: root
Functions: iptables
10

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

wget -O - http://www.commandlinefu.com/commands/browse/rss 2>/dev/null | awk '/\s*<title/ {z=match($0, /CDATA\[([^\]]*)\]/, b);print b[1]} /\s*<description/ {c=match($0, /code>(.*)<\/code>/, d);print d[1]"\n"} '
ping google.com | tee ping-output.txt
2009-01-29 10:26:59
User: root
Functions: ping tee
2

The tee (as in "T" junction) command is very useful for redirecting output to two places.

reset
2009-01-28 22:22:01
User: root
Functions: reset
250

If you bork your terminal by sending binary data to STDOUT or similar, you can get your terminal back using this command rather than killing and restarting the session. Note that you often won't be able to see the characters as you type them.

git log master | awk '/commit/ {id=$2} /\s+\w+/ {print id, $0}'
2009-01-28 13:32:08
User: root
Functions: awk
3

Useful when quickly looking for a commit id from a branch to use with git cherry-pick.

URL=www.example.com && wget -rq --spider --force-html "http://$URL" && find $URL -type d > url-list.txt && rm -rf $URL
2009-01-27 17:59:08
User: root
Functions: find rm wget
1

This spiders the given site without downloading the HTML content. The resulting directory structure is then parsed to output a list of the URLs to url-list.txt. Note that this can take a long time to run and you make want to throttle the spidering so as to play nicely.

wget -r -l1 --no-parent -nH -nd -P/tmp -A".gif,.jpg" http://example.com/images
2009-01-27 17:31:22
User: root
Functions: wget
33

This recursively downloads all images from a given website to your /tmp directory. The -nH and -nd switches disable downloading of the directory structure.

watch -n 30 uptime
2009-01-27 14:49:21
User: root
Functions: watch
3

This runs the uptime command every 30 seconds to avoid an SSH connection dropping due to inactivity. Granted there are better ways of solving this problem but this is sometimes the right tool for the job.

svn add --force *
2009-01-27 10:53:27
User: root
1

The --force option bypasses the warning if files are already in SVN.

ssh user@host "ps aux | grep httpd | wc -l"
2009-01-27 00:46:17
User: root
Functions: ssh
2

This counts the number of httpd processes running.

(cd /tmp && ls)
find /path/to/dir -type f -exec grep \-H "search term" {} \;
2009-01-26 16:32:14
User: root
Functions: find grep
-1

Simple use of find and grep to recursively search a directory for files that contain a certain term.

zip -r myfile.zip * -x \*.svn\*
rsync -av -e ssh user@host:/path/to/file.txt .
2009-01-26 13:39:24
User: root
Functions: rsync
1

You will be prompted for a password unless you have your public keys set-up.

^foo^bar
2009-01-26 13:25:37
User: root
438

Really useful for when you have a typo in a previous command. Also, arguments default to empty so if you accidentally run:

echo "no typozs"

you can correct it with

^z
cp file.txt{,.bak}
2009-01-26 12:11:29
User: root
Functions: cp
32

Uses shell expansion to create a back-up called file.txt.bak

grep -o "\(new \(\w\+\)\|\w\+::\)" file.php | sed 's/new \|:://' | sort | uniq -c | sort
2009-01-26 12:08:47
User: root
Functions: grep sed sort uniq
-2

This grabs all lines that make an instantation or static call, then filters out the cruft and displays a summary of each class called and the frequency.

sed '1000000!d;q' < massive-log-file.log
2009-01-26 11:50:00
User: root
Functions: sed
18

Sed stops parsing at the match and so is much more effecient than piping head into tail or similar. Grab a line range using

sed '999995,1000005!d' < my_massive_file
find /path/to/dir -type f -print0 | xargs -0 rm
2009-01-26 11:30:47
User: root
Functions: find xargs
12

Using xargs is better than:

find /path/to/dir -type f -exec rm \-f {} \;

as the -exec switch uses a separate process for each remove. xargs splits the streamed files into more managable subsets so less processes are required.

find . -name "*.php" -exec grep \-H "new filter_" {} \;
2009-01-26 10:43:09
User: root
Functions: find grep
0

This greps all PHP files for a given classname and displays both the file and the usage.

sudo !!
2009-01-26 10:26:48
User: root
962

Useful when you forget to use sudo for a command. "!!" grabs the last run command.

watch "df | grep /path/to/drive"
2009-01-25 21:16:41
User: root
4

This can be useful when a large remove operation is taking place.

echo "ls -l" | at midnight
2009-01-25 21:07:42
User: root
Functions: at echo
209

This is an alternative to cron which allows a one-off task to be scheduled for a certain time.

tail -10000 access_log | awk '{print $1}' | sort | uniq -c | sort -n | tail
2009-01-25 21:01:52
User: root
Functions: awk sort tail uniq
20

This uses awk to grab the IP address from each request and then sorts and summarises the top 10.

find . \( -name "*.php" -o -name "*.js" \) -exec svn propset svn:keywords Id {} \;