Commands using cat sorted by votes

Commands using cat (514)

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multiline data block parse and CSV data extraction with perl

extract data in multiline blocks of data with perl pattern matching loop Show Sample Output

This is sample output - yours may be different.

from file:


@SG: --------------------------------------------------------------------
@SG: [pmphost6] [2012-04-02 21:23:59.268]
@SG: --------------------------------------------------------------------
@SG: [SAFEGUARD STATUS]
@SG:   > RATE THRESHOLD:           30 msg/sec
@SG:   > TIME TO LIVE:           1800 sec
@SG:   > CURRENT RATE:         43.017 msg/sec  2581.000 msg/min
@SG:   > ELAPSED TIME:             60 sec
@SG:   > TIME COUNT:                0 sec
@SG:   > TIME TO LIVE COUNT:      360 sec
@SG:   > SAFEGUARD STATUS:         ON
@SG: --------------------------------------------------------------------
@SG: --------------------------------------------------------------------
@SG: [pmphost6] [2012-04-02 21:24:59.268]
@SG: --------------------------------------------------------------------
@SG: [SAFEGUARD STATUS]
@SG:   > RATE THRESHOLD:           30 msg/sec
@SG:   > TIME TO LIVE:           1800 sec
@SG:   > CURRENT RATE:         42.417 msg/sec  2545.000 msg/min
@SG:   > ELAPSED TIME:             60 sec
@SG:   > TIME COUNT:                0 sec
@SG:   > TIME TO LIVE COUNT:      420 sec
@SG:   > SAFEGUARD STATUS:         ON
@SG: --------------------------------------------------------------------
@SG: --------------------------------------------------------------------
@SG: [pmphost6] [2012-04-02 21:25:59.269]
@SG: --------------------------------------------------------------------
@SG: [SAFEGUARD STATUS]
@SG:   > RATE THRESHOLD:           30 msg/sec
@SG:   > TIME TO LIVE:           1800 sec
@SG:   > CURRENT RATE:         42.833 msg/sec  2570.000 msg/min
@SG:   > ELAPSED TIME:             60 sec
@SG:   > TIME COUNT:                0 sec
@SG:   > TIME TO LIVE COUNT:      480 sec
@SG:   > SAFEGUARD STATUS:         ON
@SG: --------------------------------------------------------------------


estract csv


DATE;RATE
2012-04-02 21:23:59.268;43.017
2012-04-02 21:24:59.268;42.417
2012-04-02 21:25:59.269;42.833

cat z.log | perl -ne 'BEGIN{ print "DATE;RATE\n"; } /\[(\d.*)\]/ && print $1; /CURRENT RATE: +(\S+) msg.*/ && print ";" .$1 . "\n"; '

hute37 · 2012-04-03 13:52:20 3

download a list of urls
This is sample output - yours may be different.
1

cat urls.txt | wget -i- -T 10 -t 3 --waitretry 1

kev · 2012-05-14 06:41:14 9
extracts 64 bytes of random digits from random lines out of /dev/random sent to stdio

Use this the next time you need to come up with a reasonably random bitstring, like for a WPA/WPA2 PSK or something. Takes a continuous stream of bytes coming from /dev/urandom, runs it through od(1), picking a random field ($0 and $1 excluded) from a random line and then prints it. Show Sample Output
This is sample output - yours may be different.
```
afca515ee00c0c92637ee8d7a476f8a380b969cc43e205bb086e622f2b77ebdd
```
1

cat /dev/urandom|od -t x1|awk 'NR > line { pos=int(rand()*15)+2;printf("%s",$pos);line=NR+(rand()*1000);digits = digits+2 } digits == 64 { print("\n");exit }'

jetdillo · 2012-08-14 19:02:00 6
Generate a 18 character password, print the password and sha512 salted hash

Generate a 18 character password from character set a-zA-Z0-9 from /dev/urandom, pipe the output to Python which prints the password on standard out and in crypt sha512 form. Show Sample Output
This is sample output - yours may be different.
```
NH6wAL58sKSkqBNUwK
$6$6ZpaL7bakRyXzrpM$TVS4d217.BDjKLEnYkPBtpR8CwXes5HI6U2pcSEoB3x9xUbXVxacEhvlvKFCi4tftwxOJs.Comh7u.GiPvA6X1
```
1

cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 18 | head -1 | python -c "import sys,crypt; stdin=sys.stdin.readline().rstrip('\n'); print stdin;print crypt.crypt(stdin)"

cnyg · 2012-11-09 00:40:22 4
Get MD5 checksum from a pipe stream and do not alter it
This is sample output - yours may be different.
1

cat somefile | tee >(openssl md5 > sum.md5) | bzip2 > somefile.bz2

bugmenot · 2013-01-14 22:03:46 6
remove recursively all txt files with number of lines less than 10
This is sample output - yours may be different.
1

find . -type f -name "*.txt" | while read; do (($(cat $THISFILE | wc -l) < 10)) && rm -vf "$THISFILE"; done

grindaizer · 2013-02-05 09:15:04 4
Check if *hardware* is 32bit or 64bit

CPU flags: rm --> 16-bit processor (real mode) tm --> 32-bit processor (? mode) lm --> 64-bit processor (long mode)
This is sample output - yours may be different.
1

cat /proc/cpuinfo | grep " lm " > /dev/null && echo 64 bits || echo 32 bits

agd · 2013-02-11 22:54:26 4
about how using internal separate field and store file content on variable
This is sample output - yours may be different.
1

OIFS=$IFS;IFS=$':';for i in $(cat -n /etc/passwd);do echo -n $i\ ** \ ;done

lbhack · 2013-04-12 04:31:31 6
sort a JSON blob

For situations where you keep JSON in a VCS and you want your diffs to be sane, such as within a Chef configuration repo.
This is sample output - yours may be different.
1

cat foo.json | python -mjson.tool

jeffgage · 2013-05-06 20:11:05 1482
Counting the source code's line numbers C/C++ Java

Count your source and header file's line numbers. This ignores blank lines, C++ style comments, single line C style comments. This will not ignore blank lines with tabs or multiline C style comments.
This is sample output - yours may be different.
1

find /usr/include/ -name '*.[c|h]pp' -o -name '*.[ch]' -print0 | xargs -0 cat | grep -v "^ *$" | grep -v "^ *//" | grep -v "^ */\*.*\*/" | wc -l

unixmonkey44446 · 2013-06-17 08:37:37 11
Filter IP's in apache access logs based on use

Show's per IP of how many requests they did to the Apache webserver
This is sample output - yours may be different.
1

cat /var/log/apache2/access_logs | cut -d ' ' -f 1 | uniq -c | sort -n

basvdburg · 2013-09-02 13:04:47 7
Filter IP's in apache access logs based on use

The first sort is necessary for ips in a list to be actually unique.
This is sample output - yours may be different.
1

cat /var/log/apache2/access_logs | cut -d' ' -f1 | sort | uniq -c | sort -n

while0pass · 2013-09-07 23:57:31 7
Prepend a text to a file.

Prepend text to a file. It doen't need temporary files, ed or sed.
This is sample output - yours may be different.
1

echo "text to prepend" | cat - file

leni536 · 2013-12-18 15:54:17 11
Converts all windows .URL shortcuts in a directory to linux (gnome) .desktop shortcuts
This is sample output - yours may be different.
1

find . -name "*.URL" | while read file ; do cat "$file" | sed 's/InternetShortcut/Desktop Entry/' | sed '/^$URL\|\[$/!d' > "$file".desktop && echo "Type=Link" >> "$file".desktop ; done

pholz · 2014-01-30 09:57:08 7
count total number of lines of ruby code

Adapted from http://stackoverflow.com/questions/1358540/how-to-count-all-the-lines-of-code-in-a-directory-recursively#answer-1359246
This is sample output - yours may be different.
1

( find ./ -name '*.rb' -print0 | xargs -0 cat ) | wc -l

gdelfino · 2014-01-30 15:35:38 15
calculate how much bogomips one cpu core has (assuming you have 4 cores).

on some distro's you have to replace "BogoMIPS" with "bogomips". Show Sample Output
This is sample output - yours may be different.
```
#([04:33:58][root@fritz:~]#)cat /proc/cpuinfo | grep BogoMIPS | uniq | sed 's/^.*://g' | awk '{print($1 / 4) }'
52.8375
```
1

cat /proc/cpuinfo | grep BogoMIPS | uniq | sed 's/^.*://g' | awk '{print($1 / 4) }'

derpat · 2014-03-01 03:44:03 6
Skype conversation logs to IRC-format logs
This is sample output - yours may be different.
1

cat skype_log | sed -s 's/$\[.*\]$ $.*$: $.*$/<\2> \3/'

noisy · 2014-03-09 18:17:44 7
Fetch the requested virtual domains and their hits from log file

The command will read the apache log file and fetch the virtual host requested and the number of requests.
This is sample output - yours may be different.
1

cat /etc/httpd/logs/access.log | awk '{ print $6}' | sed -e 's/\[//' | awk -F'/' '{print $1}' | sort | uniq -c

suyashjain · 2014-10-13 13:39:53 8
Use socat to emulate an SMTP mail SERVER

Lots of scripts show you how to use socat to send an email to an SMTP server; this command actually emulates an SMTP server! It assumes the client is only sending to one recipient, and it's not at all smart, but it'll capture the email into a log file and the client will stop retrying. I used this to diagnose what emails were being sent by cron and subsequently discarded, but you can use it for all sorts of things. Show Sample Output
This is sample output - yours may be different.
```
EHLO host.example.com
MAIL FROM:<root@example.com>
RCPT TO:<root@example.com>
DATA
Received: by host.example.com (Postfix, from userid 1234)
	id 955; Wed, 26 Nov 2014 12:56:03 -0800 (PST)
From: root@example.com (Cron Daemon)
To: root@example.com
Subject: Cron <root@example.com>    
Content-Type: text/plain; charset=UTF-8
Message-Id: <2014112.57348E5@host.example.com>
Date: Wed, 26 Nov 2014 12:56:01 -0800 (PST)

foobar: cannot remove user's mustache.
.
QUIT
```
1

socat TCP4-LISTEN:25,fork EXEC:'bash -c \"echo 220;sleep 1;echo 250;sleep 1;echo 250;sleep 1;echo 250;sleep 1;echo 354;sleep 1;echo 250; timeout 5 cat >> /tmp/socat.log\"'

pfudd · 2014-11-26 21:14:05 15
Monitor system load and print out top offending processes

This checks the system load every second and if it's over a certain threshold (.8 in this example), it spits out the date, system loads and top 4 processes sorted by CPU. Additionally, the \a in the first echo creates an audible bell.
This is sample output - yours may be different.
1

while sleep 1; do if [ $(echo "$(cat /proc/loadavg | cut -d' ' -f1) > .8 " | bc) -gt 0 ]; then echo -e "\n\a"$(date)" \e[5m"$(cat /proc/loadavg)"\e[0m"; ps aux --sort=-%cpu|head -n 5; fi; done

tyzbit · 2014-12-08 15:44:40 8
draw rhomb
This is sample output - yours may be different.
1

a=$(b=$(($LINES/2));f() { for c in $(seq $b); do for i in $(seq $c);do echo x;done|xargs echo;done };paste <(f) <(f|tac|tr 'x' '-') <(f|tac|tr 'x' '-') <(f)|tr '\t' ' ');(cat <<<"$a"|tac;cat <<<"$a")|tr '-' ' '

knoppix5 · 2015-04-08 02:33:05 16
Find out the active XOrg Server DISPLAY number (from outside)

It's useful when you cannot access your env (systemd) or the process DISPLAY variable is not set. Perhaps also when you have a multi-head/user configuration. Show Sample Output
This is sample output - yours may be different.
```
:0
```
1

for p in $(pgrep -t $(cat /sys/class/tty/tty0/active)); do d=$(awk -v RS='\0' -F= '$1=="DISPLAY" {print $2}' /proc/$p/environ 2>/dev/null); [[ -n $d ]] && break; done; echo $d

geyslan · 2015-05-18 20:01:20 38
Get File Names from touch commands

retrieve file names back from touch commands for them Show Sample Output
This is sample output - yours may be different.
```
Input:
touch 01_intro.compressed.pdf; sleep 0.1;
touch 02_points.compressed.pdf; sleep 0.1;
touch 03_points.pdf; sleep 0.1;
touch lewis_pca_derivs.pdf; sleep 0.1;
touch shlens_pca.pdf; sleep 0.1;

Output:
01_intro.compressed.pdf
02_points.compressed.pdf
03_points.pdf
lewis_pca_derivs.pdf
shlens_pca.pdf
```
1

touch files.txt; cat reorder_files.sh | while read line; do x=`echo $line | sed 's/touch $[a-z0-9\.]\+.*.pdf$;.*/\1/'`; echo $x >> files.txt ; done;

programmer · 2016-04-19 11:01:17 12
Create Bash script to change modification time of files

Create a bash script to change the modification time for each file in 'files.txt' such that they are in the same order as in 'files.txt' File name for bash script specified by variable, 'scriptName'. It is made an executable once writing into it has been completed. Show Sample Output
This is sample output - yours may be different.
```
Input:
01_intro.compressed.pdf
02_points.compressed.pdf
03_points.pdf

Output:
#!/bin/sh

touch 01_intro.compressed.pdf; sleep 0.5;
touch 02_points.compressed.pdf; sleep 0.5;
touch 03_points.pdf; sleep 0.5;
```
1

scriptName="reorder_files.sh"; echo -e '#!/bin/sh\n' > "${scriptName}"; cat files.txt | while read file; do echo "touch ${file}; sleep 0.5;" >> "${scriptName}"; done; chmod +x "${scriptName}";

programmer · 2016-04-19 11:52:00 15
Basic sed usage with xargs to refactor a node.js depdendency
This is sample output - yours may be different.
1

cat matching_files.txt | xargs sed -i '' "s/require('global-module')/require('..\/some-folder\/relative-module')/"

Trindaz · 2016-11-17 03:26:09 20
‹ First < 7 8 9 10 11 > Last ›

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Pause Current Thread

Hold ctrl and press z to pause the current thread. Run $fg to resume it.

Count opening and closing braces in a string.

This function counts the opening and closing braces in a string. This is useful if you have eg long boolean expressions with many braces and you simply want to check if you didn't forget to close one.

Perl Command Line Interpreter

My Programming Languages professor assigned my class a homework assignment where we had to write a Perl interpreter using Perl. I really like Python's interactive command line interpreter which inspired this Perl script.

Create a mirror of a local folder, on a remote server

Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Define shell variable HISTIGNORE so that comments (lines starting with #) appear in shell history

I was surprised to find that with RedHat bash, I could not find any comment lines (begining with #) in my bash shell history. Surprised because in Mageia Linux this works. It turns out that RedHat's bash will keep comment lines if in my .bashrc, I define: export HISTIGNORE=' cd "`*: PROMPT_COMMAND=?*?' Why have comment lines in shell history? It's a handy and convenient way to make proto-commands (to be completed later) and for storing brief text data that is searchable in shell history.

list process ids for given program

Compute the average number of KB per file for each dir

Shorter version using --tag

Print a row of 50 hyphens

change exif data in all jpeg's

this takes every jpg in the current directory and changes the exif data for manufactur and model. in my case i change it to LOMO LC-A because my scanner puts his data in there :]

Give all those pictures the same name format, trailing zeros please for the right order, offset to merge different collections of pictures

When you have different digital cameras, different people, friends and you want to merge all those pictures together, then you get files with same names or files with 3 and 4 digit numbers etc. The result is a mess if you copy it together into one directory. But if you can add an offset to the picture number and set the number of leading zeros in the file name's number then you can manage. OFFS != 0 and LZ the same as the files currently have is not supported. Or left as an exercise, hoho ;) I love NF="${NF/#+(0)/}",it looks like a magic bash spell.

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Commands using cat (514)

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