Commands tagged bash sorted by votes

Commands tagged bash (821)

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Launch command in backgroup or not

If $INBACK is set, command will launch in foreground and inverse. Very useful in script ! We could apply the inverse comportement like that : eval command ${INBACK:+&}
This is sample output - yours may be different.
-1

eval <command> ${INBACK:-&}

Zulu · 2012-04-05 03:50:57 3

Use exit codes that actually means something.

Use meaningful exit codes change "source" to "cat" to view output instead of assigning Show Sample Output

-1

source <(egrep '^#define EX_.*' /usr/include/sysexits.h | sed -e 's/#define/declare -r/g' | sed 's/\//#/g' | sed -e 's/\s\{1,\}/ /g' | sed -e 's/ $[0-9]$/\=\1/'g )

fishdaemon · 2012-09-21 13:30:37 10

creates or attachs to screen

There is no need to use the shell or construct. Screen offers varius ways of detaching and reattaching. man screen and look for -[rRdD]. to create a named session: sdr moo hide: resume: sdr moo Show Sample Output
This is sample output - yours may be different.
```
n/a
```
-1

alias sdr="screen -dR"

tox2ik · 2012-10-22 21:46:26 4
Show git branches by date - useful for showing active branches

simple table
This is sample output - yours may be different.
-1

for k in `git branch -r|awk '{print $1}'`;do echo -e `git show --pretty=format:"%Cgreen%ci_%C(blue)%c r_%Cred%cn_%Creset" $k|head -n 1`$k;done|sort -r|awk -F"_" '{printf("%s %17s %-22s %s\n",$1,$2,$3,$4)}'

varon · 2012-10-29 12:38:24 6

Find out if a module is installed in perl (and what version)

This attempts to load a Perl Module (-M flag) and use version 9999, since no module has a version this high, Perl exits either a) telling you the version of the module installed or b) tells you it can't find the module. Show Sample Output

-1

perl -MModule::Name\ 9999 -e 1

three18ti · 2013-01-15 22:51:39 4

check your up to date delicious links.

This commands queries the delicious api then runs the xml through xml2, grabs the urls cuts out the first two columns, passes through uniq to remove duplicates if any, and then goes into linkchecker who checks the links. the links go the blacklist in ~/.linkchecker/blacklist. please see the manual pages for further info peeps. I took me a few days to figure this one out. I how you enjoy it. Also don't run these api more then once a few seconds you can get banned by delicious see their site for info. ~updated for no recursive Show Sample Output
This is sample output - yours may be different.
```
1 http://www.jokosher.org/
1 http://www.learnopenoffice.org/calccontents.htm
1 http://ubcd4win.com/forum/index.php?showtopic=9630
1 http://212.182.0.171/dwww/
1 http://www.smarthomeforum.com/start/default.asp
1 http://www.sjrcc.edu/
1 http://curvedns.on2it.net/docs
1 http://www.smarthomeforum.com/
```
-1

curl -k https://Username:Password@api.del.icio.us/v1/posts/all?red=api | xml2| \grep '@href' | cut -d\= -f 2- | sort | uniq | linkchecker -r0 --stdin --complete -v -t 50 -F blacklist

bbelt16ag · 2013-05-04 17:43:21 8
Batch resize all images to a width of 'X' pixels while maintaing the aspect ratio

Batch resize all images to a width of 'X' pixels while maintaing the aspect ratio. This makes uses of ImageMagick to make life easier.
This is sample output - yours may be different.
-1

mogrify -resize SIZE_IN_PIXELS *.jpg

o0110o · 2013-07-05 14:14:04 6
Removes single line from known_hosts file

Quickly remove the conflicting line (key) from current users known_hosts file when there is an SSH host conflict. Very nice when you get tired of writing out full commands. Ideally you would place this into your .bash_profile Usage: rhost [n] Example: rhost 33 (removes line 33 from ~/.ssh/known_hosts) Function assumes the $HOME exists, you could alternatively use "~/.ssh/known_hosts" Mac OSX likes a space for sed -i "$1" d
This is sample output - yours may be different.
-1

rhost() { if [[ $1 =~ ^[0-9]+$ ]]; then sed -i "$1"d ${HOME}/.ssh/known_hosts; else echo "rhost [n]"; fi }

lowjax · 2013-08-01 21:10:34 13
find all minimum values in file with at least 100 lines
This is sample output - yours may be different.
-1

for ff in directory; do numLines=`wc -l $ff`; numLines=$(echo $numLines | sed 's/ .*//g'); min=$(sort -nrk 1 $ff | tail -1); if [ $numLines -gt 100 ]; then echo $min >> minValues; fi;done;

user1234 · 2013-09-23 04:04:52 7
A simple overview of memory usage refreshed at user designated intervals.

This command shows a high level overview of system memory and usage refreshed in seconds. Change -n 10 to you desired refresh interval. Show Sample Output
This is sample output - yours may be different.
```
Every 10.0s: free -m                                                                   Fri Jan  3 15:58:44 2014

             total       used       free     shared    buffers     cached
Mem:         12001       3565       8435          0        268       1613
-/+ buffers/cache:       1682      10318
Swap:         1951          0       1951
```
-1

watch -n 10 free -m

Darkstar · 2014-01-04 10:10:15 12
Show best quote from reddit to your terminal

The rsstail is the python version (python-rsstail). The final command pipe it on every new line to gammu and a connected phone rsstail -o -n 1 --f 'RedditQuote: {title}' http://www.reddit.com/r/quotes/new/.rss | while read line; do /usr/bin/gammu --sendsms TEXT +*yournumber* -text "$line"; done Show Sample Output
This is sample output - yours may be different.
```
RedditQuote: ?You're beautiful, but you're empty. No one could die for you.? &#8213; Antoine de Saint-Exup?ry, The Little Prince
```
-1

rsstail -o -n 1 --f 'RedditQuote: {title}' http://www.reddit.com/r/quotes/new/.rss

Youpfu · 2014-01-08 15:33:48 8
Show total cumulative memory usage of a process that spawns multiple instances of itself
This is sample output - yours may be different.
-1

CMD=chrome ; ps h -o pmem -C $CMD | awk '{sum+=$1} END {print sum}'

pdxdoughnut · 2014-01-08 23:05:09 8
Generrate Cryptographically Secure RANDOM PASSWORD

Explination: https://stackoverflow.com/questions/2257441/random-string-generation-with-upper-case-letters-and-digits/23728630#23728630 Why 16 Characters: https://www.wired.com/story/7-steps-to-password-perfection/ Show Sample Output
This is sample output - yours may be different.
```
a7Bt4WGSz8hjJWIP
```
-1

python -c "import string; import random;print(''.join(random.SystemRandom().choice(string.ascii_uppercase + string.digits + string.ascii_lowercase) for _ in range(16)))"

rootduck · 2019-06-14 17:35:12 39
shell bash iterate number range with for loop

iterating range of numer with for loop in shell or bash Show Sample Output
This is sample output - yours may be different.
```
10
11
12
13
14
15
16
17
18
19
20
```
-1

rangeBegin=10; rangeEnd=20; for numbers in $(eval echo "{$rangeBegin..$rangeEnd}"); do echo $numbers;done

aysadk · 2019-07-26 09:19:44 234
shell bash iterate number range with for loop

"seq" has an additional parameter to use as INCREMENT. # seq FIRST INCREMENT LAST https://linux.die.net/man/1/seq Show Sample Output
This is sample output - yours may be different.
```
1
2
3
4
5
```
-1

for i in $(seq 1 5) ; do echo $i ; done

guilsson · 2019-07-29 18:34:12 215
Fork bomb (don't actually execute)

“$0” is a variable returning the name of the script that you call it in — so running “./$0&” twice amounts to the script running itself in a separate process twice. Show Sample Output
This is sample output - yours may be different.
```
#!/bin/bash
./$0&
./$0&
```
-1

echo -e “\x23\x21/bin/bash\n\.\/\$\0\&\n\.\/\$\0\&” > bomb.sh && ./bomb.sh

realkstrawn93 · 2021-04-30 19:33:40 141
read a file with table like data

This will print out the third column of every line in FILE. Useful for many files in /proc or *csv data. Show Sample Output
This is sample output - yours may be different.
```
3
```
-2

echo 1 2 3 > FILE; while read -a line; do echo ${line[2]}; done < FILE

occam · 2009-03-06 15:32:40 6
Easy Regex based mass renaming

Allows for quick mass renaming, assuming the user has some familiarity with regular expressions. Basically, it replaces the original_file_name in the output of ls with "mv -v original_file_name new_file_name" and passes the output to sh. Show Sample Output
This is sample output - yours may be different.
```
$ ls ~/manga/ | sed -rn -e 's/naruto_(...\.zip)/mv -v & \1/p' | sh
`naruto_431.zip' -> `431.zip'
`naruto_432.zip' -> `432.zip'
`naruto_433.zip' -> `433.zip'
`naruto_434.zip' -> `434.zip'
$
```
-2

ls /some/directory | sed -rn -e 's/input_file_regex/mv -v & output_file_name/p' | sh

polar · 2009-03-25 09:20:15 10
Bash Alias That Plays Music from SomaFM

This is the alias command that I discussed in my prior release which you can add to your ~/.bashrc. This command asks for the station name and then connects to somafm, Great for those who have linux home entertainment boxes and ssh enabled on them, just for the CLI fiends out there ( I know I'm one of them ;) You can find future releases of this and many more scripts at the teachings of master denzuko - denzuko.co.cc.
This is sample output - yours may be different.
-2

alias somafm='read -p "Which station? "; mplayer --reallyquiet -vo none -ao sdl http://somafm.com/startstream=${REPLY}.pls'

denzuko · 2009-05-05 12:13:46 3
create tar.gz archive

Create a single tar.gz archive I know it's a very basic one, but it's one I keep forgetting. Show Sample Output
This is sample output - yours may be different.
```
/path/to/dir/or/file/
/path/to/dir/or/file/file1.ext
/path/to/dir/or/file/file2.ext
```
-2

tar -pczf archive_name.tar.gz /path/to/dir/or/file

ryuslash · 2009-07-17 19:53:02 30
List path of binaries
This is sample output - yours may be different.
-2

echo $PATH|awk -F: ' { for (i=1; i <= NF; i++) print $i }'

nitins · 2009-08-12 07:56:56 4
Echo the local IP addresses of the machines on your local network

If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.
This is sample output - yours may be different.
-2

for i in 192.168.1.{61..71};do ping -c 1 $i &> /dev/null && echo $i;fi;done

AlecSchueler · 2009-08-26 06:04:24 11
Checks apache's access_log file, strips the search queries and shoves them up your e-mail

It's not a big line, and it *may not* work for everybody, I guess it depends on the detail of access_log configuration in your httpd.conf. I use it as a prerotate command for logrotate in httpd section so it executes before access_log rotation, everyday at midnight.
This is sample output - yours may be different.
-2

cat /var/log/httpd/access_log | grep q= | awk '{print $11}' | awk -F 'q=' '{print $2}' | sed 's/+/ /g;s/%22/"/g;s/q=//' | cut -d "&" -f 1 | mail youremail@isp.com -s "[your-site] search strings for `date`"

isma · 2009-11-22 03:03:06 9
Normalize volume in your mp3 library

Execute this in the root of your music library and this recurses through the directories and normalizes each folder containing mp3s as a batch. This assumes those folders hold an album each. The command "normalize-audio" may go by "normalize" on some systems.
This is sample output - yours may be different.
-2

find . -type d -exec sh -c "normalize-audio -b \"{}\"/*.mp3" \;

Mikelifeguard · 2009-12-08 03:13:13 7
Purge frozen messages in Exim

Although Exim will purge frozen (undeliverable) messages over time, the command "exim -Mrm #id#" where #id# is a particular message ID will purge a message immediately. Being lazy, I don't want to type the command for each frozen message, so I wrote the one-liner to do it for me.
This is sample output - yours may be different.
-2

for i in `mailq | awk '$6 ~ /^frozen$/ {print $3}'`; do exim -Mrm $i; done

rjamestaylor · 2010-01-13 21:28:45 3
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delay execution of a command that needs lots of memory and CPU time until the resources are available

[ 2000 -ge "$(free -m | awk '/buffers.cache:/ {print $4}')" ] returns true if less than 2000 MB of RAM are available, so adjust this number to your needs. [ $(echo "$(uptime | awk '{print $10}' | sed -e 's/,$//' -e 's/,/./') >= $(grep -c ^processor /proc/cpuinfo)" | bc) -eq 1 ] returns true if the current machine load is at least equal to the number of CPUs. If either of the tests returns true we wait 10 seconds and check again. If both tests return false, i.e. 2GB are available and machine load falls below number of CPUs, we start our command and save it's output in a text file. The ( ( ... ) & ) construct lets the command run in background even if we log out. See http://www.commandlinefu.com/commands/view/3115/ .

List PCI device with class and vendor/device IDs

This is a quick replacement for lspci if you need to know what's in a given system but pciutils is not installed. You then need something that can look up the IDs from pci.ids if you want the verbose output.

Detect illegal access to kernel space, potentially useful for Meltdown detection

Based on capsule8 agent examples, not rigorously tested

Change the homepage of Firefox

This command modifies the preferences file of Firefox that is located in .mozilla/firefox/*.default/prefs.js. It edits the file with sed and the -i option. Then it searches the string "browser.startup.homepage", and the string next to it (second string). Finally, it replaces the second string with the new homepage, that is http://sliceoflinux.com in the example. It doesn't work if you haven't set any homepage.

Grep all non-ascii character in file

It will highlight non-ascii character in a file. those character can cause problem for some application parsing ascii file.

Debug redirects between production reloads

Watches the headers of a curl, following any redirects and printing only the HTTP status and the location of the possible redirects.

Video Google download

Download google video with wget. Or, if you wish, pass video URL to ie mplayer to view as stream. 1. VURL: replace with url. I.e. http://video.google.com/videoplay?docid=12312312312312313# 2. OUPUT_FILE : optionally change to a more suited name. This is the downloaded file. I.e. foo.flv # Improvements greatly appreciated. (close to my first linux command after ls -A :) ) Breakedown pipe by pipe: 1. wget: html from google, pass to stdout 2. grep: get the video url until thumbnailUrl (not needed) 3. grep: Strip off everything before http:// 4. sed: urldecode 5. echo: hex escapes 6. sed: stipr of tailing before thumbnailUrl 7. wget: download. Here one could use i.e. mplayer or other...

Convert seconds into minutes and seconds

This is a very simple way to input a large number of seconds and get a more useful value in minutes and seconds. Avoids useless use of echo.

for too many arguments by *

$ grep ERROR *.log -bash: /bin/grep: Argument list too long $ echo *.log | xargs grep ERROR /dev/null 20090119.00011.log:DANGEROUS ERROR

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" }

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Commands tagged bash (821)

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