Commands using grep sorted by votes

Commands using grep (1,935)

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watch iptables counters

This will allow you to watch as matches occur in real-time. To filter out only ACCEPT, DROP, LOG..etc, then run the following command: watch 'iptables -nvL | grep -v "0 0" && grep "ACCEPT"' The -v is used to do an inverted filter. ie. NOT "0 0"
This is sample output - yours may be different.
7

watch --interval 0 'iptables -nvL | grep -v "0 0"'

Code_Bleu · 2009-08-22 18:18:05 51
Show apps that use internet connection at the moment. (Multi-Language)

Show apps that use internet connection at the moment. Can be used to discover what programms create internet traffic. Skip the part after awk to get more details, though it will not work showing only unique processes. This version will work with other languages such as Spanish and Portuguese, if the word for "ESTABLISHED" still contain the fragment "STAB"(e.g. "ESTABELECIDO") Show Sample Output
This is sample output - yours may be different.
```
firefox
http
ktorrent
opera
python
```
7

netstat -lantp | grep -i stab | awk -F/ '{print $2}' | sort | uniq

ProMole · 2009-09-19 14:54:31 9
32 bits or 64 bits?
This is sample output - yours may be different.
7

sudo lshw -C cpu|grep width

sliceoflinux · 2009-09-24 11:43:00 6
Display the history and optionally grep

Place this in your .bash_profile and you can use it two different ways. If you issue 'h' on its own, then it acts like the history command. If you issue: h cd Then it will display all the history with the word 'cd'
This is sample output - yours may be different.
7

h() { if [ -z "$1" ]; then history; else history | grep "$@"; fi; }

haivu · 2009-10-13 21:49:37 10
See non printable caracters like tabulations, CRLF, LF line terminators ( colored )

For fancier and cleaner output, try the following snippet : showendlines(){ while read i; do od --address-radix=n --width=$(wc -c <<< "$i") -c <<< "$i" | perl -pe 's/.\K\s{2,3}//g'; done < $1 | grep --color '\\.'; } Now you can run that with : showendlines <FILE> Thanks to prince_jammys to "debug" my English ;)
This is sample output - yours may be different.
7

od -c <FILE> | grep --color '\\.'

sputnick · 2009-12-11 02:15:48 9
Show when filesystem was created

Knowing when a filesystem is created , you can deduce when an operating system was installed . find filesystem device (/dev/) informations by using the cat /etc/fstab command. Show Sample Output
This is sample output - yours may be different.
```
gnu@robby:~$ sudo dumpe2fs -h /dev/sda1 | grep 'created'
[sudo] password for gnu: 
dumpe2fs 1.41.4 (27-Jan-2009)
Filesystem created:       Wed Oct 14 16:56:35 2009
```
7

dumpe2fs -h /dev/DEVICE | grep 'created'

eastwind · 2009-12-12 14:47:33 14
Block the 6700 worst spamhosts

The above url contains over 6700 of the common ad websites. The command just pastes these into your /etc/hosts. Show Sample Output
This is sample output - yours may be different.
```
-
```
7

wget -q -O - http://someonewhocares.org/hosts/ | grep ^127 >> /etc/hosts

torrid · 2009-12-14 17:11:16 8
Do some learning...
This is sample output - yours may be different.
7

for i in $(ls /usr/bin); do whatis $i | grep -v nothing; done | more

Abiden · 2010-01-26 06:15:54 7
Define words and phrases with google.

This version works on Mac (avoids grep -P, adding a sed step instead, and invokes /usr/bin/perl with full path in case you have another one installed). Still requires that you install perl module HTML::Entities ? here's how: http://www.perlmonks.org/?node_id=640489
This is sample output - yours may be different.
7

define(){ local y="$@";curl -sA"Opera" "http://www.google.com/search?q=define:${y// /+}"|grep -Eo '<li>[^<]+'|sed 's/^<li>//g'|nl|/usr/bin/perl -MHTML::Entities -pe 'decode_entities($_)';}

gthb · 2010-01-30 13:08:03 14
See why a program can't seem to access a file

Sometimes a program refuses to read a file and you're not sure why. You may have display_errors turned off for PHP or something. In this example, fopen('/var/www/test/foo.txt') was called but doesn't have read access to foo.txt. Strace can tell you what went wrong. E.g., if php doesn't have read access to the file, strace will say "EACCESS (Permission denied)". Or, if the file path you gave doesn't exist, strace will say "ENOENT (No such file or directory)", etc. This works for any program you can run from the command-line, e.g., strace python myapp.py -e open,access... Note: the above command uses php-cli, not mod_php, which is a different SAPI with diff configs, etc. Show Sample Output
This is sample output - yours may be different.
```
open("/var/www/test/filename.txt", O_RDONLY|O_LARGEFILE) = -1 EACCES (Permission denied)
```
7

strace php tias.php -e open,access 2>&1 | grep foo.txt

rkulla · 2010-04-20 19:42:42 6
deaggregate ip ranges

Taking file with ip ranges, each on it's own line like: cat ipranges.txt 213.87.86.160-213.87.86.193 213.87.87.0-213.87.88.255 91.135.210.0-91.135.210.255 command returns deaggregated ip ranges using ipcalc deaggregate feature like that: 213.87.86.160/27 213.87.86.192/31 213.87.87.0/24 213.87.88.0/24 91.135.210.0/24 Useful for configuring nginx geo module Show Sample Output
This is sample output - yours may be different.
```
213.87.86.160/27
213.87.86.192/31
213.87.87.0/24
213.87.88.0/24
91.135.210.0/24
```
7

/bin/grep - ipranges.txt | while read line; do ipcalc $line ; done | grep -v deag

tf8 · 2010-04-20 21:13:00 4
grep binary (hexadecimal) patterns

-P activates the Perl regular expression mode.
This is sample output - yours may be different.
7

grep -P "\x05\x00\xc0" mybinaryfile

grinob · 2010-06-30 23:07:24 8
Lets Tux say the random fact. [add it to .bashrc to see it in new terminal window]
This is sample output - yours may be different.
7

wget randomfunfacts.com -O - 2>/dev/null|grep \<strong\>|sed "s;^.*<i>$.*$</i>.*$;\1;"|cowsay -f tux

unixmonkey10612 · 2010-07-01 18:31:36 3
Display connections histogram

Displays a connection histogram of active tcp connections. Works even better under an alias. Thanks @Areis1 for sharing this one.
This is sample output - yours may be different.
7

netstat -an | grep ESTABLISHED | awk '\''{print $5}'\'' | awk -F: '\''{print $1}'\'' | sort | uniq -c | awk '\''{ printf("%s\t%s\t",$2,$1); for (i = 0; i < $1; i++) {printf("*")}; print ""}'\''

mramos · 2010-07-09 00:25:45 42
Look for English words in /dev/urandom

* to get the English dictionary: wget http://www.mavi1.org/web_security/wordlists/webster-dictionary.txt Show Sample Output
This is sample output - yours may be different.
```
...
rINg
riNg
akAL
tais
TaRF
bASS
DoCK
raCe
...
```
7

head -100000 /dev/urandom | strings > temp.txt && for w in $(cat webster-dictionary.txt); do if [ ${#w} -gt 3 ]; then grep -io $w temp.txt; fi; done

rugina · 2010-12-23 01:58:56 10
Terminal Keyboard Shortcut list

This command will give you a list of available keyboard shortcuts according to stty. Show Sample Output
This is sample output - yours may be different.
```
Terminal shortcut keys

intr=Ctrl+C
quit=Ctrl+\
erase=Ctrl+?
kill=Ctrl+U
eof=Ctrl+D
eol=Shift+Ctrl+?
eol2=Shift+Ctrl+?
swtch=Shift+Ctrl+?
start=Ctrl+Q
stop=Ctrl+S
susp=Ctrl+Z
rprnt=Ctrl+R
werase=Ctrl+W
lnext=Ctrl+V
flush=Ctrl+O
```
7

echo -e "Terminal shortcut keys\n" && sed -e 's/\^/Ctrl+/g;s/M-/Shift+/g' <(stty -a 2>&1| sed -e 's/;/\n/g' | grep "\^" | tr -d ' ')

cicatriz · 2011-02-10 17:38:05 5

This one-liner will use strace to attach to all of the currently running apache processes output and piped from the initial "ps auxw" command into some awk. Show Sample Output

This is sample output - yours may be different.

ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace
Process 7313 attached - interrupt to quit
Process 7395 attached - interrupt to quit
Process 7396 attached - interrupt to quit
Process 7397 attached - interrupt to quit
Process 7398 attached - interrupt to quit
Process 7399 attached - interrupt to quit
Process 7401 attached - interrupt to quit
Process 7403 attached - interrupt to quit
Process 7448 attached - interrupt to quit
Process 7468 attached - interrupt to quit
Process 7469 attached - interrupt to quit
attach: ptrace(PTRACE_ATTACH, ...): No such process
[pid  7313] select(0, NULL, NULL, NULL, {0, 48000} <unfinished ...>
[pid  7395] poll([{fd=11, events=POLLIN}, {fd=10, events=POLLIN}, {fd=9, events=POLLIN}, {fd=8, events=POLLIN}, {fd=7, events=POLLIN}, {fd=6, events=POLLIN}, {fd=5, events=POLLIN}, {fd=4, events=POLLIN}, {fd=85, events=POLLIN}, {fd=19, events=POLLIN}], 10, -1 <unfinished ...>
[pid  7396] semop(1572864, {{0, -1, SEM_UNDO}}, 1 <unfinished ...>
[pid  7397] semop(1572864, {{0, -1, SEM_UNDO}}, 1 <unfinished ...>
[pid  7398] poll([{fd=15, events=POLLIN}, {fd=19, events=POLLIN}], 2, -1 <unfinished ...>
[pid  7399] semop(1572864, {{0, -1, SEM_UNDO}}, 1 <unfinished ...>
[pid  7401] poll([{fd=15, events=POLLIN}, {fd=19, events=POLLIN}], 2, -1 <unfinished ...>
[pid  7403] poll([{fd=15, events=POLLIN}, {fd=19, events=POLLIN}], 2, -1 <unfinished ...>
[pid  7448] poll([{fd=15, events=POLLIN}, {fd=19, events=POLLIN}], 2, -1 <unfinished ...>
[pid  7468] poll([{fd=15, events=POLLIN}, {fd=19, events=POLLIN}], 2, -1 <unfinished ...>
[pid  7469] poll([{fd=15, events=POLLIN}, {fd=19, events=POLLIN}], 2, -1 <unfinished ...>
[pid  7313] <... select resumed> )      = 0 (Timeout)
[pid  7313] gettimeofday({1300139401, 36665}, NULL) = 0
[pid  7313] waitpid(-1, 0xffdc0a68, WNOHANG|WSTOPPED) = 0
[pid  7313] select(0, NULL, NULL, NULL, {1, 0}) = 0 (Timeout)
[pid  7313] gettimeofday({1300139402, 39688}, NULL) = 0
[pid  7313] waitpid(-1, 0xffdc0a68, WNOHANG|WSTOPPED) = 0
[pid  7313] select(0, NULL, NULL, NULL, {1, 0} <unfinished ...>
Process 7313 detached
Process 7395 detached
Process 7396 detached
Process 7397 detached
Process 7398 detached
Process 7399 detached
Process 7401 detached
Process 7403 detached
Process 7448 detached
Process 7468 detached
Process 7469 detached

ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace

px · 2011-03-14 21:45:22 34

Display all readline binding that use CTRL

Useful for getting to know the available keyboard shortcuts. Show Sample Output

bind -p | grep -F "\C"

root · 2009-02-03 16:22:14 57

Count the number of queries to a MySQL server
This is sample output - yours may be different.
6

echo "SHOW PROCESSLIST\G" | mysql -u root -p | grep "Info:" | awk -F":" '{count[$NF]++}END{for(i in count){printf("%d: %s\n", count[i], i)}}' | sort -n

bpfx · 2009-02-05 14:24:20 40
list processes with established tcp connections (without netstat)

Uses lsof to list open network connections (file descriptors), grepping for only those in an established state
This is sample output - yours may be different.
6

lsof -i -n | grep ESTABLISHED

systemj · 2009-02-05 15:28:11 37
Display any tcp connections to apache

Sometimes apache will get stuck in an established state where you can't get a list of the connecting IP's from mod_status... not a good thing when you need to ban an abusive ip.
This is sample output - yours may be different.
6

for i in `ps aux | grep httpd | awk '{print $2}'`; do lsof -n -p $i | grep ESTABLISHED; done;

Shadow · 2009-02-05 17:50:52 67
Change string in many files at once and more.

Find all files that contain string XXX in them, change the string from XXX to YYY, make a backup copy of the file and save a list of files changed in /tmp/fileschanged.
This is sample output - yours may be different.
6

find . -type f -exec grep -l XXX {} \;|tee /tmp/fileschanged|xargs perl -pi.bak -e 's/XXX/YYY/g'

drossman · 2009-02-16 02:55:23 59
Getting information about model no. of computer

This command gives a model information of a computer. Also useful in determining the host is a VM machine or actual physical machine. Show Sample Output
This is sample output - yours may be different.
```
dmidecode | grep -i prod
       Product Name: HP dx2480 MT(FX800PA)
       Product Name: 0B08h
```
6

dmidecode | grep -i prod

rockon · 2009-02-25 23:05:17 8
Quick case-insenstive partial filename search

This is a simple command, but extremely useful. It's a quick way to search the file names in the current directory for a substring. Normally people use "ls *term*" but that requires the stars and is not case insensitive. Color (for both ls and grep) is an added bonus.
This is sample output - yours may be different.
6

alias lg='ls --color=always | grep --color=always -i'

kFiddle · 2009-04-11 23:15:12 8
eth-tool summary of eth# devices

Give the Speed and Link status of eth# 0-3. This is sort of what mii-tool does, but eth-tool is better, yet lacks device discovery. Show Sample Output
This is sample output - yours may be different.
```
eth0
        Speed: Unknown! (65535)
        Link detected: no
eth1
        Speed: Unknown! (65535)
        Link detected: no
eth2
        Speed: 1000Mb/s
        Link detected: yes
eth3
        Speed: Unknown! (65535)
        Link detected: no
```
6

for M in 0 1 2 3 ; do echo eth$M ;/sbin/ethtool eth$M | grep -E "Link|Speed" ; done

Wubby · 2009-04-22 19:32:41 9
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Hostname tab-completion for ssh

This is meant for the bash shell. Put this function in your .profile and you'll be able to use tab-completion for sshing any host which is in your known_hosts file. This assumes that your known_hosts file is located at ~/.ssh/known_hosts. The "complete" command should go on a separate line as such: function autoCompleteHostname() { local hosts=($(awk '{print $1}' ~/.ssh/known_hosts | cut -d, -f1)); local cur=${COMP_WORDS[COMP_CWORD]}; COMPREPLY=($(compgen -W '${hosts[@]}' -- $cur )) } complete -F autoCompleteHostname ssh

Copy a file using dc3dd and watch its progress (very nice alternative to dd)

Requires the dc3dd package - available at http://dc3dd.sourceforge.net

Find usb device in realtime

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

Create a random file of a certain, and display progress along the way.

SIZE is the number of gigabytes and the file name is at the end. Random data is generated by encrypting /dev/zero, similar to other techniques posted on here.

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Generate a random text color in bash

The expression $(( $RANDOM * 6 / 32767 + 1 )) generates a random number between 1 and 6, which is then inserted into the escape sequence \e[3_m to switch the foreground color of the terminal to either red, green, yellow, blue, purple or cyan. The color can be reset using the escape sequence \e[0m. The full list of colors can be found here: https://wiki.archlinux.org/index.php/Color_Bash_Prompt#List_of_colors_for_prompt_and_Bash

multiline data block parse and CSV data extraction with perl

extract data in multiline blocks of data with perl pattern matching loop

Execute a command with a timeout

Check tcp-wrapping support

This function returns TRUE if the application supports tcp-wrapping or FALSE if not by reading the shared libraries used by this application.

Get a regular updated list of zombies

Shows all those processes; useful when building some massively forking script that could lead to zombies when you don't have your waitpid()'s done just right.

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Commands using grep (1,935)

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