Commands using cat sorted by votes

Commands using cat (514)

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Get all URL With Extension from File
This is sample output - yours may be different.
0

cat File.txt | grep -io 'http://www.acme.com/a/files/.*.pdf'| uniq

nedzoul · 2014-10-31 14:51:57 8
Have a user generate an ssh key if it does not already exist and spit it in bold red to stdout
This is sample output - yours may be different.
0

if [ -e ~/.ssh/id_rsa.pub ] ; then echo $'\033[1;31m' ; cat ~/.ssh/id_rsa.pub ; echo $'\033[0m' ; else ssh-keygen -t rsa -b 4096 -f ~/.ssh/id_rsa -t rsa -P ""; echo $'\033[1;31m' ; cat ~/.ssh/id_rsa.pub ; echo $'\033[0m'; fi

sdoradus · 2014-12-01 03:48:19 8
Copy your ssh public key to a server from a machine that doesn't have ssh-copy-id

same as above, however without the chmod, you wont be able to SSH to the machine as the openssh server will require tigther permissions
This is sample output - yours may be different.
0

cat ~/.ssh/id_rsa.pub | ssh user@machine "mkdir ~/.ssh; cat >> ~/.ssh/authorized_keys; chmod -R ~/.ssh"

omarrar · 2014-12-04 18:55:53 9
See crontabs for all users that have one

This is not exhaustive but after checking /etc/cron* is a good way to see if there are any other jobs any users may have set. Note: this is a repost from a comment "flatcap" made on http://www.commandlinefu.com/commands/view/3726/print-crontab-entries-for-all-the-users-that-actually-have-a-crontab#comment, for which I am grateful and I take no credit.
This is sample output - yours may be different.
0

for USER in /var/spool/cron/*; do echo "--- crontab for $USER ---"; cat "$USER"; done

tyzbit · 2014-12-11 19:48:46 15
compute the total disk space consumed by a list of files

Given a list of filenames, one per line, in /tmp/filelist, calculate the total sum disk usage.
This is sample output - yours may be different.
0

LISTCOUNT=0; LISTSIZE=0; cat /tmp/filelist | while read FF; do FILESIZE=$(stat -c%s "$FF"); LISTSIZE=$[LISTSIZE+${FILESIZE}]; echo listsize: $LISTSIZE; LISTCOUNT=$[LISTCOUNT+1]; echo listcount: $LISTCOUNT; done | tail -2

mwtzzz · 2015-01-13 00:53:04 8
Generate a random alphanumeric string (works on Mac)
This is sample output - yours may be different.
0

cat /dev/urandom | strings | grep -o '[[:alnum:]]' | head -n 15 | tr -d '\n'; echo

rekky · 2015-01-31 23:07:23 8
Copy ssh keys to user@host to enable password-less ssh logins with permissions alignment.

One liner that basically duplicates ssh-copy-id functionality by taking care of most common issues of SSH password-less ssh logins: - missing key on the remote server - braindead permissions *cough* RHEL *cough* Show Sample Output
This is sample output - yours may be different.
```
Host key copied
```
0

cat ~/.ssh/id_rsa.pub | ssh user@hostname 'cat >> ~/.ssh/authorized_keys && chmod 600 ~/.ssh/authorized_keys && chmod 700 ~/.ssh && echo "Host key copied"'

rde · 2015-02-17 01:46:03 9

This helps me determine which repo I want to use for downloading ISO files Show Sample Output

cat repos.txt | while read line; do echo $line | cut -d"/" -f 3 | fping -e ;done

rawm · 2015-02-17 06:34:07 8

search "<keyword>" <file>

Add this to your bash profile, then quickly & easily (regex) search for and highlight keywords, with full text output.
This is sample output - yours may be different.
0

function search() { cat ${@:1} | grep --color=always -E "$1|$" }

miscreant · 2015-03-18 18:34:11 40
Compare a remote file with a local file

opens the output of some command as a file so this also works with graphical editors like meld, kdiff3 etc meld <(ssh $remote_site cat .zshrc) .zshrc
This is sample output - yours may be different.
0

diff <(ssh $remote_site cat $file) $file

hal8 · 2015-05-09 11:11:56 11
Display a formated comma seperated spreadsheet .csv with letters and numbers for easy viewing and to check formula entry..

In addition one can evaluate the formulas in the venerable spreadsheet command sc, with an additional command. function csvev () { cat $1 | sed -e '1i,,,,,,,' |sed -e 's/=sum/@sum/g' -e 's/=SUM/@SUM/g' | psc -k -d, | sed -e 's/\"@SUM(/@SUM(/' -e 's/)"/)/' | sed '/@SUM/ { s/rightstring/let/; }' | sed -e '/= "=/s/rightstring/let/' -e '/= "=/s/"//g' | sed 's/= =/= /g' | sc ; } I will post this command separately as well. Show Sample Output
This is sample output - yours may be different.
```
0	a     b     c              d        e        f        g        h            j       k    l  m  n  o  p
     1	Name  Date  email          Amount1  Amount2  Amount3  Amount4  Total
     2	Erik  2015  sf@none.net    10       20       30       10       =SUM(D2:G2)
     3	joe   2014  joe@none.net   5        10       15       10       =SUM(D3:G3)
     4	jill  2015  jill@none.net  10       25       30       10       =SUM(D4:G4)
     5	                                                               =SUM(H2:H4)  =G2+G3  =H2
```
0

function sheet () { cat "$1" | sed '1s/^/a,b,c,d,e,f,g,h,j,k,l,m,n,o,p\n/' | column -s , -tn | nl -v 0 ; }

eakinc · 2015-07-13 03:14:35 9
Evaluate simple formulas in a .csv spreadsheet by converting and piping to the venerable sc.

Requires psc, sed, sc, and cat. Working with csv spreadsheets with formulas in them to evaluate the formulas using sc. View the formulas in a numbered and lettered formated in command line. function sheet () { cat "$1" | sed '1s/^/a,b,c,d,e,f,g,h,j,k,l,m,n,o,p\n/' | column -s , -tn | nl -v 0 ; }
This is sample output - yours may be different.
0

cat FILE.csv |sed -e '1i,,,,,' |sed -e 's/=sum/@sum/g' -e 's/=SUM/@SUM/g' |psc -k -d, |sed -e 's/\"@SUM(/@SUM(/' -e 's/)"/)/' -e '/@SUM/ { s/rightstring/let/; }' -e '/= "=/s/rightstring/let/' -e '/= "=/s/"//g' -e 's/= =/= /g' |sc

eakinc · 2015-07-13 04:11:31 10
Prepend text to a file
This is sample output - yours may be different.
0

echo "text to prepend" | cat - file

rahouni · 2015-07-17 11:15:34 9
tsv file to json file

Need to change values of 'field 1'...'field 3' to column names. input_file.tsv is the tab file you want to conver output_file.json is the file that is created with the json output. Assumes your tsv has no headers.
This is sample output - yours may be different.
0

export FIELDS=field_1,field_2,field_3; cat input_file.tsv| ruby -rjson -ne 'puts ENV["FIELDS"].split(",").zip($_.strip.split("\t")).inject({}){|h,x| h[x[0]]=x[1];h}.to_json' > output_file.json

prees · 2015-07-24 15:00:34 9
Outputs unique error messages from the apache log and count, sorted by frequency

Outputs unique error messages from the apache log, sorted by frequency. Tested on log format: [Wed Aug 26 00:00:00 2015] [error] [client xx.xx.xx.xx] Error message here Show Sample Output
This is sample output - yours may be different.
```
63 PHP PHP Warning: json_encode(): Invalid UTF-8 sequence in argument
10 Warning: Warning: preg_match() expects parameter 2 to be string, array given
7 PHP PHP Warning: Invalid argument supplied for foreach() in ...
5 PHP PHP Warning: implode(): Invalid arguments passed in ...
1 PHP PHP Parse error: syntax error, unexpected ',' in ...
```
0

cat /var/log/apache2/error.log | awk '{out=$9;for(i=9;i<=NF;i++){out=out" "$i}; print out}' | sed s/,\ referer.*// | sort | uniq -c | sort -nr

cmattoon · 2015-08-26 14:14:12 10
printing text between tags
This is sample output - yours may be different.
0

echo or cat something | grep -Po '(?<=text_before).*(?=text_after)'

petteriIII · 2015-09-11 09:19:57 9
Monitor memory fine-grained usage (e.g. firefox)

I have modified the original one-liner to allow it to manage multiple PIDs. However, I haven't found the way it can work properly with the watch command. NOTE: brace expand must be activated via "set -B" in order to this script can work. Show Sample Output
This is sample output - yours may be different.
```
961936 KB
```
0

cat $(echo "ls /proc/{`pidof firefox | sed -e 's/$/,/' -e 's/ /,/g'`}/smaps 2>/dev/null" | bash) | awk '/Rss/{sum += $2; } END{print sum, "KB"}'

pchalim · 2015-09-30 22:22:53 9
Info cpu

4.1.6-1-ARCH Info cpu
This is sample output - yours may be different.
0

cat /proc/cpuinfo | less

olto · 2015-10-01 04:34:03 10
Operating system identification data

Files contain operating system identification data Show Sample Output
This is sample output - yours may be different.
```
NAME=
ID=
PRETTY_NAME=
ANSI_COLOR=
HOME_URL=
SUPPORT_URL=
```
0

cat /etc/os-release

olto · 2015-10-22 04:31:36 9
finds all bean ids in all xml files from the current folder

finds all xml files greps them for extracts the bean id sorts the ids creates a list of distinct entries, a unique list of bean ids Show Sample Output
This is sample output - yours may be different.
```
groupManager
groupPermissionsDelegate
groupPermissionsDelegate
handleResolver
hashRegistry
hazelcastCacheCompactor
hazelcastCacheConfigManager
```
0

find . -iname "*.xml" | xargs cat | grep '<bean[^>]\+id=' | sed 's/.*id="$[^"]\+$".*/\1/g' | sort | uniq -u

gruzilla · 2015-11-06 07:57:22 10
memory information
This is sample output - yours may be different.
0

cat /proc/meminfo

blasetherexaler · 2015-11-11 05:09:52 9
Merge files in current directory
This is sample output - yours may be different.
0

find . -type f -name '*.csv' -exec cat {} + >> merged.csv

swarzynski · 2015-11-19 10:06:21 10
View formatted table of users on the system

Useful to see login name, UID, GID, home dir, and login shells of all users. Show Sample Output
This is sample output - yours may be different.
```
root    x  0  0  root    /root      /bin/bash
daemon  x  1  1  daemon  /usr/sbin  /usr/sbin/nologin
bin     x  2  2  bin     /bin       /usr/sbin/nologin
```
0

cat /etc/passwd | column -nts :

HeinrichHartmann · 2015-12-08 11:24:58 10
Find Rhyming Words

rhyme time mime rhyme lowrez Juarez
This is sample output - yours may be different.
0

rhyme() { { cat /usr/share/dict/words; printf %s\\n "$1"; } | rev | sort | rev | grep -FxC15 -e "${1?}" | grep -Fxve "$1" | shuf -n1; }

lowrez · 2016-01-02 03:24:44 13
output your mp3 file over SSH on a remote computer's speaker

This command is useful for sending mp3-sound by the quick way using SSH.
This is sample output - yours may be different.
0

cat /home/user/file.mp3 | ssh -C user@host mpg123 -

Zeben · 2016-03-29 12:30:09 12
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Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Check host port access using only Bash:

kill process by name

Or even easier, if it's available: $ killall firefox I have no idea why you would want to rely on two unusual dependencies to do something that can be done a hundred ways from coreutils...

File rotation without rename command

Rotates log files with "gz"-extension in a directory for 7 days and enumerates the number in file name. i.e.: logfile.1.gz > logfile.2.gz I needed this line due to the limitations on AIX Unix systems which do not ship with the rename command.

Find the most recently changed files (recursively)

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Check if the Debian package was used since its installation/upgrade.

This script compares the modification date of /var/lib/dpkg/info/${package}.list and all the files mentioned there. It could be wrong on noatime partitions. Here is non-oneliner: #!/bin/sh package=$1; list=/var/lib/dpkg/info/${package}.list; inst=$(stat "$list" -c %X); cat $list | ( while read file; do if [ -f "$file" ]; then acc=$(stat "$file" -c %X); if [ $inst -lt $acc ]; then echo used $file exit 0 fi; fi; done exit 1 )

add a backup (or any other) suffix to a file

Very helpful when you've got complex filenames and needs to change just some small parts of it. Renaming a file called "i-made-a-small-typo-right-here" to "i-made-a-big-typo-right-here": $ mv -vi i-made-a-{small,big}-typo-right-here You could also copy multiple files, edit, remove, process, etc.

ionice limits process I/O, to keep it from swamping the system (Linux)

This command is somewhat similar to 'nice', but constrains I/O usage rather than CPU usage. In particular, the '-c3' flag tells the OS to only allow the process to do I/O when nothing else is pending. This dramatically increases the responsiveness of the rest of the system if the process is doing heavy I/O. There's also a '-p' flag, to set the priority of an already-running process.

A formatting test for David Winterbottom: improving commandlinefu for submitters

Commandlinefu.com is great but has a few bugs when people are submitting new commands: . 1. There is no preview button. This was a minor inconvenience before, but now is a major problem since new commands won't show up to be edited until they have been moderated. . 2. White space in the description field and in the comments is almost completely lost. People resort to using periods in between paragraphs to force a line break. Indentation of code is ridiculous. . 3. Many characters get munged. . 3a. For example, a less than character in the description gets read as an HTML tag and discarded. In order to type a less than, I've had to type "<" (I hope that comes out right). Unfortunately, when re-editing a command, the HTML entity is turned into a literal less than character, which I have to change back by hand before saving. 3b. Some unicode characters work in the description field, but turn into ugly literal HTML strings when put in the sample output or in an additional command using the $ prefix. . For example, here is a unicode character: ❥ $ Here is the same character after a dollar sign: ❥ . 3c. Some unicode characters don't work anywhere. Bizarrely, it appears to be the most commonly needed ones, such as Latin-1 accented characters. Here are some examples, . Bullet: ?, Center dot: ?, Umlaut u: ?. . 4. Here is an example of the greater than, >, and less than,

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Commands using cat (514)

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