Commands using cat sorted by votes

Commands using cat (514)

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Automatd ssh public key setup without ssh-copy-id

Some servers don't have ssh-copy-id, this works in those cases. It will ask for the destination server, this can be IP, hostname, or user@hostname if different from current user. Ssh keygen will let you know if a pubkey already exists on your system and you can opt to not overwrite it.
This is sample output - yours may be different.
-2

echo 'Host or User@Host?:'; read newserver && ssh-keygen -N "" -t rsa -f ~/.ssh/id_rsa ; ssh $newserver cat <~/.ssh/id_rsa.pub ">>" ~/.ssh/authorized_keys ; ssh $newserver

alf · 2010-05-07 06:24:53 4
count how many cat processes are running
This is sample output - yours may be different.
-2

ps -a |grep cat |wc -l

schmiddim · 2010-09-22 23:57:19 3
List your MACs address
This is sample output - yours may be different.
-2

cat `ls -r /sys/class/net/*/address` | sort -u

jaimerosario · 2011-06-02 23:16:37 3
Generate an XKCD #936 style 4 word password

The first grep rejects capitalised words since the dict has proper nouns in it that you mightn't want to use. The second grep rejects words with ending in apostrophe s, and the third forces the words to be at least 15 characters long. Show Sample Output
This is sample output - yours may be different.
```
counterproductive unreasonableness multimillionaires extemporaneously
```
-2

cat /usr/share/dict/words | grep -P ^[a-z].* | grep -v "'s$" | grep -Pv ^.\{1,15\}$ | shuf -n4 | tr '\n' ' ' | sed 's/$/\n/'

bugmenot · 2011-08-15 01:03:48 6
Cat files in a directory; for loop command

The better alternative to #9756. I don't think I'd ever use the original command, but this one was so bad I had to post this. Sorry. 1. $(ls) is dumb, and will give errors if you have an alias like "ls -Fs" 2. clear is better and more portable than reset state. 3. if you're interested in differences, then use diff, not cat.
This is sample output - yours may be different.
-2

for f in *; do clear; cat $f; sleep .3; done

toddkaufmann · 2011-11-25 17:10:47 6
Cat files in a directory; for loop command

Original submitted version would break if any filenames had whitespaces in them. The command is a Bad Idea anyhow, because you will end up `cat`ing a binary or something else specacularly bad.
This is sample output - yours may be different.
-2

for file in ./*; do cat "$file"; sleep 0.3

DopeGhoti · 2011-11-28 20:10:57 3
View external IP
This is sample output - yours may be different.
-2

wget -q ip.nu && cat index.html

VictorBjelkholm · 2012-03-23 03:14:37 3
Copy paste contents quickly and save as a file

Write script or commands in notepad/Editplus/MS word etc, copy the contents, type the above command and click on enter now, paste by right click-ing the mouse. Entire contents in the clip-board gets pasted now again click on Enter to go to new line/next line. Press Ctrl+D to close/save the file. Not always required to vi to create a new file.
This is sample output - yours may be different.
-2

cat > file_name

michaelrozar17 · 2012-03-27 11:38:09 4
download a list of urls
This is sample output - yours may be different.
-2

cat urls.txt | xargs -n1 curl -O --max-time 10 --retry 3 --retry-delay 1

kev · 2012-05-14 06:38:06 4
How to execute and encrypted and password-protected bash script?

echo "ls" > script.bash; This is my script, a simple 'ls'. gpg -c script.bash; Here I encrypt and passord-protect my script. This creates file script.bash.gpg. cat script.bash.gpg | gpg -d --no-mdc-warning | bash Here I open file script.bash.gpg, decrypt it and execute it.
This is sample output - yours may be different.
-2

echo "ls" > script.bash; gpg -c script.bash; cat script.bash.gpg | gpg -d --no-mdc-warning | bash

betsubetsu · 2013-03-10 09:34:12 9
List all password hashes
This is sample output - yours may be different.
-2

cat /etc/shadow

dsetton · 2014-02-01 19:48:05 6
having root on server, add user's public key to his keys (no password required)
This is sample output - yours may be different.
-2

cat user_public_key.pub | ssh root@<host> "cat | su -c 'mkdir -m 700 -p ~/.ssh && cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys' <user>"

noisy · 2016-05-09 08:48:40 14
small CPU benchmark with PI, bc and time.

Broken in two parts, first get the number of cores with cat /proc/cpuinfo |grep proc|wc -l and create a integer sequence with that number (xargs seq), then have GNU parallel loop that many times over the given command. Cheers! Show Sample Output
This is sample output - yours may be different.
```
...
66983895228684783123552658213144957685726243344189303968642624341077\
3226978028073189154411010446823252716201052652272111660396

real	0m31,847s
user	0m59,085s
sys	0m0,151s
```
-2

time cat /proc/cpuinfo |grep proc|wc -l|xargs seq|parallel -N 0 echo "scale=4000\; a$1$\*4" '|' bc -l

kostis · 2018-12-06 05:15:24 674
Generrate Cryptographically Secure RANDOM PASSWORD

Change :alnum: to :graph: for all printable characters Show Sample Output
This is sample output - yours may be different.
```
FH170AB1DXb4dHlX
```
-2

cat /dev/urandom |tr -c -d '[:alnum:]'|head -c 16;echo

AndrewM · 2019-06-17 17:51:04 36
Broadcast message to all logged in terminal users.

Show message in file "welcome" to all logged in terminal users. Show Sample Output
This is sample output - yours may be different.
```
Broadcast Message from william@linux-wsue                                      
        (/dev/pts/0) at 12:05 ...                                              
                                                                               
Welcome to Command-line-fu
```
-3

cat welcome | wall

Williebee · 2009-02-14 18:12:50 12
Eliminate duplicate lines on a file
This is sample output - yours may be different.
-3

cat file1.txt | uniq > file2.txt

olafrv · 2009-03-01 05:10:10 11
Reset scrambled screen

^V means CTRL-V [ENTER] means ENTER key
This is sample output - yours may be different.
-3

cat [ENTER]^V^O[ENTER]^D

minliu2k · 2009-04-17 13:16:56 13
View SuSE version

Displays SuSE release information Show Sample Output
This is sample output - yours may be different.
```
SUSE LINUX Enterprise Server 9 (x86_64)
VERSION = 9
PATCHLEVEL = 4
```
-3

cat /etc/SuSE-release

sharfah · 2009-05-20 17:28:12 20
CPU model
This is sample output - yours may be different.
-3

cat /proc/cpuinfo

theIndianMaiden · 2009-08-19 11:09:17 13
Get a text on a position on the file and store in a variable with a specific separator
This is sample output - yours may be different.
-3

TIMEUNIT=$( cat a | grep -n "timescale" | awk -F ":" '{ print $1 } ' )

conradojr · 2009-10-27 18:01:26 3
Get your external IP address

bash neto..
This is sample output - yours may be different.
-3

exec 3<>/dev/tcp/whatismyip.com/80; echo -e "GET /automation/n09230945.asp HTTP/1.0\r\nHost: whatismyip.com\r\n" >&3; a=( $(cat <&3) ); echo ${a[${#a[*]}-1]};

yaccovs · 2009-11-03 21:57:00 6
Pipe music over netcat with mpg123

I think I picked this one up from Hak5 (yeah I know.. kinda lame)
This is sample output - yours may be different.
-3

#Client# cat "The Meters - People Say.mp3" | nc -vv 192.168.1.100 8080; #Server# nc -vv -l -s 192.168.1.100 -p 8080 | mpg123 -v -

Abiden · 2010-01-30 08:50:17 7
Check whether laptop is running on battery or cable

Show Sample Output
This is sample output - yours may be different.
```
present:                 yes
capacity state:          ok
charging state:          charged
present rate:            0 mA
remaining capacity:      2000 mAh
present voltage:         16566 mV
```
-3

cat /proc/acpi/battery/*/state

adrruiz · 2010-06-13 23:00:54 4
Replace tabs with spaces in file

Replaces tabs in output with spaces. Uses perl since sed seems to work differently across platforms.
This is sample output - yours may be different.
-3

cat file_with_tabs.txt | perl -pe 's/\t/ /g'

nikc · 2010-07-11 13:01:22 37
close stderr
This is sample output - yours may be different.
-3

cat aaaaaa 2>&-

totti · 2011-09-14 20:55:26 3
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Get the full path to a file

Useful in scripts when the file is passed in as an argument. Eg. $ filepath=$(realpath $1)

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

Compare two CSV files, discarding any repeated lines

The value for the sort command's -k argument is the column in the CSV file to sort on. In this example, it sorts on the second column. You must use some form of the sort command in order for uniq to work properly.

Update all Docker Images

Create a directory and go inside it

$_ expands to the last argument of the last command that was executed

Put split files back together, without a for loop

After splitting a file, put them all back together a lot faster then doing $cat file1 file2 file3 file4 file5 > mainfile or $for i in {0..5}; do cat file$i > mainfile; done When splitting, be sure to do split -d for getting numbers instead of letters

Prints per-line contribution per author for a GIT repository

Figures out total line contribution per author for an entire GIT repo. Includes binary files, which kind of mess up the true count. If crashes or takes too long, mess with the ls-file option at the start: git ls-files -x "*pdf" -x "*psd" -x "*tif" to remove really random binary files git ls-files "*.py" "*.html" "*.css" to only include specific file types Based off my original SVN version: http://www.commandlinefu.com/commands/view/2787/prints-total-line-count-contribution-per-user-for-an-svn-repository

Show running services (using systemctl)

function to edit your history file

eh stands for Edit History . Frequently, I'll mistype a command, and then step back through my history and correct the command. As a result, both the correct and incorrect commands are in my history file. I wanted a simple way to remove the incorrect command so I don't run it by mistake. . When running this function, first the ~/bash_history file is updated, then you edit the file in vi, and then the saved history file is loaded back into memory for current usage. . while in vi, remember that `Shift-G` sends you to the bottom of the file, and `dd` removes a line. . this command is different than bash built-in `fc` because it does not run the command after editing.

calulate established tcp connection of local machine

If you want prepend/append text just wrap in echo: $echo Connected: `netstat -an|grep -ci "tcp.*established"`

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Commands using cat (514)

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