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 1485
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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Display all shell functions set in the current shell environment

Uses the shell builtin `declare` with the '-f' flag to output only functions to grep out only the function names. You can use it as an alias or function like so: alias shfunctions="builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ '" shfunctions () { builtin declare -f | command grep --color=never -E '^[a-zA-Z_]+\ '; }

Use all the cores or CPUs when compiling

Force make command to create as many compile processes as specified (4 in the example), so that each one goes into one core or CPU and compilation happens in parallel. This reduces the time required to compile a program by up to a half in the case of CPUs with 2 cores, one fourth in the case of quad cores... and so on.

find previously entered commands

Searches bash-history in reverse order (last entered commands first). Pressing ctrl+r again shows the next matching entry.

Download Video & extract only a specific Time of it

Because this does not download more of the video than necessary, it is faster (especially with long videos).

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Print lines in a text file with numbers in first column higher or equal than a value

A text file contains thousands of numbers. This command prints lines were the number is greater or equal than a specified value (134000000).

awk using multiple field separators

You can use multiple field separators by separating them with | (=or). This may be helpful when you want to split a string by two separators for example. #echo "one=two three" | awk -F "=| " {'print $1, $3'} one three

Advanced python tracing

Trace python statement execution and syscalls invoked during that simultaneously

Encrypted archive with openssl and tar

The lifehacker way: http://lifehacker.com/software/top/geek-to-live--encrypt-your-data-178005.php#Alternate%20Method:%20OpenSSL "That command will encrypt the unencrypted-data.tar file with the password you choose and output the result to encrypted-data.tar.des3. To unlock the encrypted file, use the following command:" $ openssl des3 -d -salt -in encrypted-data.tar.des3 -out unencrypted-data.tar

Display usb power mode on all devices

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Commands using cat (514)

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