All commands

All commands (14,216)

Enhanced Buffer in order to avoir mistakes with redirections that empty your files

Issues & improvements Race conditions: the check for writability then mv is not fully atomic — another process could create/remove/change the target between the test and mv. Permissions and ownership: mv will preserve contents but the resulting file may have the temp file's permissions/ownership (mktemp default). Signal safety: if interrupted (SIGINT, SIGTERM) the temp file may remain. Portability: uses bash-compatible constructs but relies on mktemp and -a (POSIX [ -a ] is obsolete; better to use -e). Better error messages and exit status handling. Allow optional mode to write to stdout when no filename given. Support setting desired file mode (umask or chmod) and preserve atomic replace semantics. Enhanced version Uses safer existence test ([ -e ] not deprecated -a). Installs traps to clean up temp file on exit/signals. Preserves mode of the existing file (if it exists) or allows a chmod option. Attempts a safer atomic replace: write to temp in same directory as target when a filename is supplied (reduces window for cross-filesystem mv failure and preserves atomicity). If no filename given, writes temp contents to stdout. Returns non-zero on failure and prints concise errors to stderr.
This is sample output - yours may be different.
-3

buffer(){ tty -s&&return; d=${1:-/tmp}; tmp=$(mktemp "$d/.b.XXXXXX")||return; trap 'rm -f "$tmp"' EXIT; cat>"$tmp"||{ rm -f "$tmp"; return 1; }; [ -z "$1" ]&&{ cat "$tmp"; rm -f "$tmp"; return 0; }; mv -f "$tmp" "$1"; }

cryptology_codes · 2025-09-14 21:19:55 192
Android VOLUME_DOWN
This is sample output - yours may be different.
-1

adb shell input keyevent KEYCODE_VOLUME_DOWN

alikhalil · 2025-08-13 13:22:00 47
Extract one file from a remote tar.gz and put it where you want it

This fetches ipfs v0.36.0 for GNU/LInux and puts it in ~/bin without a tmp file or anything else. This works if you already have ~/bin. The `--strip-components=1` flag removes the "kubo" directory in this case. If you have a tar with an even deeper directory structure, say: `some/other/directory/file`, you can just use `--strip-components=3` and it will only extract `file` for you. `-C ~/bin` puts the file in the designated path. In this case, `~/bin`. Show Sample Output
This is sample output - yours may be different.
```
$ tar -C ~/bin/ --strip-components=1 -xzf <( curl -L https://dist.ipfs.tech/kubo/v0.36.0/kubo_v0.36.0_linux-amd64.tar.gz ) kubo/ipfs
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 49.0M  100 49.0M    0     0  26.1M      0  0:00:01  0:00:01 --:--:-- 26.1M
```
2

tar --strip-components=1 -C ~/bin/ -xzf <( curl -L https://dist.ipfs.tech/kubo/v0.36.0/kubo_v0.36.0_linux-amd64.tar.gz ) kubo/ipfs

renich · 2025-08-12 03:38:07 51
List memory percentage per user

Show top 10 users by memory combined consumption in percentage. Show Sample Output
This is sample output - yours may be different.
```
user01 1.6
user02 2.8
user03 2.8
user04 3.2
user05 4.9
user06 5.5
user07 6.6
user08 13.6
user09 13.7
user10 16.5
```
0

ps aux | awk '{arr[$1]+=$4}; END {for (i in arr) {print i,arr[i]}}' | sort -hk2 | tail -10

Raboo · 2025-08-01 07:06:55 46
Display history of reboots

If you need to see a list of the reboots of your system with date and time stamps then on a Linux with systemd you can use (as non-root) the command: journalctl --list-boots This could be useful if you are trying to track when a power outage occurred. An alternative is: /bin/sudo grep "^-" /var/log/boot.log ^ This only shows the boot start date/times while the journalctl command shows a "LAST ENTRY" associated with each "BOOT ID". Show Sample Output
This is sample output - yours may be different.
```
$ journalctl --list-boots
IDX BOOT ID                          FIRST ENTRY                 LAST ENTRY                 
[data redacted]
```
0

$ journalctl --list-boots # display tabular history of reboots

mpb · 2025-07-22 14:52:34 20
Tapping screen for TikTok using shell script
This is sample output - yours may be different.
0

while true; do input tap $(wm size | awk -F 'x' '{print $1/2 " " $2/2}'); done

wuseman1 · 2025-05-27 13:32:54 114
Mount SMB v1 share on Linux
This is sample output - yours may be different.
0

mount -t cifs -o username=administrator,password=xxx,vers=1.0,sec=ntlmv2 //192.168.0.30/nas_share /mnt/win_share

swarzynski · 2025-03-20 08:16:19 124
Download and Extract mp3 from Youtube Video

This will download a video when given the link and it will extract the audio from the video. The filename will be the same as the video's title. File extension in mp3.
This is sample output - yours may be different.
8

yt-dlp --extract-audio --audio-format mp3 --audio-quality 0 -o "%(title)s.%(ext)s" <youtube_link_here>

keyboardsage · 2024-11-22 19:54:54 98
Get a random quote from Breaking Bad

Hit an API with curl returning a random quote, then parse the result with jq. Show Sample Output
This is sample output - yours may be different.
```
"A guy that clean has to be dirty." -- Hank Schrader
```
9

curl -s https://api.breakingbadquotes.xyz/v1/quotes | jq -r '.[] | "\"\(.quote)\" -- \(.author)"'

malathion · 2024-09-09 14:58:37 66
Matrix - Just 1 wobbly line rather then a rain! (shorter)

No sample. Try it and see the magic!
This is sample output - yours may be different.
3

while true; do printf "\e[32m%*s\e[0m" $(tput cols) $(shuf -e {0..1} -n $(tput cols)); sleep 0.1; done

wuseman1 · 2024-09-02 00:44:33 60
Matrix - Just 1 wobbly line rather then a rain!

Remove clear; sleep 5 and echo for not doing sample!
This is sample output - yours may be different.
1

clear; sleep 5; echo 'while :; do printf "\e[32m%*s\e[0m" $(tput cols) $(shuf -e {0..1} -n $(($(tput lines) * $(tput cols)))); sleep 0.1; done'

wuseman1 · 2024-09-02 00:40:34 60
This command will help you to hunt the current mysql query statement in real time. (-R is deprecated, using updated -Y)
This is sample output - yours may be different.
1

tshark -s 512 -i eno1 -n -f'tcp dst port 3306' -Y'<mysql.query>' -T fields -e <mysql.query>

wuseman1 · 2024-08-26 19:29:05 84
Read /etc/passwd with printf in a smarter and shorter way then some deliberately obfuscated shell commands from unethicals.
This is sample output - yours may be different.
1

eval "$(E3LFbgu='CAT /ETC/PASSWD';printf %s "${E3LFbgu~~}")"

wuseman1 · 2024-08-26 19:20:48 49
Portscan entire internet (ipv4)
This is sample output - yours may be different.
0

(masscan 0.0.0.0/0 -p80 --banner --exclude 255.255.255.255 --max-rate 100000|tee internet_ips_to_block_ranges.txt 2>&1 /dev/null); 1&> /dev/null

wuseman1 · 2024-08-26 19:14:02 38
In emergency situations, in order not to panic, shut down the following port on the network with the following rather then shutting down the PC.
This is sample output - yours may be different.
2

fuser -k 445/tcp

wuseman1 · 2024-08-26 19:11:03 34
Generate a correct mac addr.

1) The last sed expression ensures the unicast/multicast bit is set to zero 2) The greedy space replacements are for portability across UNIX seds Show Sample Output
This is sample output - yours may be different.
```
a0:94:47:e1:f7:59
```
1

od -An -N6 -tx1 /dev/urandom |sed -e 's/^ *//' -e 's/ */:/g' -e 's/:$//' -e 's/^$.$[13579bdf]/\10/'

wuseman1 · 2024-08-26 19:10:02 48
Launch hidden commands.
This is sample output - yours may be different.
0

/bin/bash -c "exec ls"

wuseman1 · 2024-08-26 19:08:24 210
Do we use: 'Wayland' OR 'x11' (systemd version)
This is sample output - yours may be different.
1

loginctl show-session $XDG_SESSION_ID -p Type

wuseman1 · 2024-08-26 19:07:02 28
Do we use: 'Wayland' OR 'x11'
This is sample output - yours may be different.
1

printf 'Session is: %s\n' "${DISPLAY:+X11}${WAYLAND_DISPLAY:+WAYLAND}"

wuseman1 · 2024-08-26 19:06:32 29
View emerge log by date in humand friendly time
This is sample output - yours may be different.
1

awk -F: '{print strftime("%Y-%m-%d -> %X --> ", $1),$2}' /var/log/emerge.log

wuseman1 · 2024-08-26 19:03:05 24
Find the right intel-ucode firmware for Intel GPU
This is sample output - yours may be different.
1

iucode_tool -S -l /lib/firmware/intel-ucode/*

wuseman1 · 2024-08-26 19:01:55 23
Disable Show More Options on Windows 11

Enable it again: reg delete "HKEY_CURRENT_USER\Software\Classes\CLSID\{86ca1aa0-34aa-4e8b-a509-50c905bae2a2}" /f Show Sample Output
This is sample output - yours may be different.
```
Successfully completed.
```
0

reg add "HKCU\Software\Classes\CLSID\{86ca1aa0-34aa-4e8b-a509-50c905bae2a2}\InprocServer32" /f /ve

wuseman1 · 2024-08-26 18:56:51 22
Generate a QR code in the terminal
This is sample output - yours may be different.
2

printf 'https://www.gentoo.org/' | curl -F-=\<- qrenco.de

wuseman1 · 2024-08-26 18:41:24 15
Shuffle a reversed string without new lines (Simple way to create a progress bar)
This is sample output - yours may be different.
0

while true; do slumpad_eversed=$(echo "$eversed_part" | grep -o . | shuf | tr -d '\n'); tput cr && tput el && echo -n "$r_part$slumpad_eversed" ; sleep 1 ; done

wuseman1 · 2024-08-26 18:37:43 59
Shuffle two letters randomly

Use variable: letters=("a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z")
This is sample output - yours may be different.
0

while true; do shuffled_letter1=$(printf "%s\n" "${letters[@]}" | shuf -n 1); shuffled_letter2=$(printf "%s\n" "${letters[@]}" | shuf -n 1); printf "%s%s\r" "$shuffled_letter1" "$shuffled_letter2"; sleep 0.1; done

wuseman1 · 2024-08-26 18:36:29 55
1 2 3 > Last ›

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Quick plotting of a function

The arguments of "seq" indicate the starting value, step size, and the end value of the x-range. "awk" outputs (x, f(x)) pairs and pipes them to "graph", which is part of the "plotutils" package.

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"

On Screen micro display for battery and CPU temperature. nifty, small, omnipresent

My firefox overheats my cpu, sometimes above 90 degrees Celsius ( hence the name? ) To keep an eye on temperature, I put this command inside KAlarm ( a kind of cron) to be repeated every minute, for 5 seconds, color red ( default for osd_cat). Its pretty, ultra small, displays a micro 2 lines text on every desktop and over everything and do not steal focus or interrupt any task. I get the information passively, in the low profile bottom of the screen. Of course you can use it inside a terminal. Just do it: watch -n 60 'acpi -t | osd_cat -p bottom'

Processes by CPU usage

Create an animated gif from a Youtube video

requires "youtube-dl" -- sure you can do this with wget and some more obscurity but why waste your time when this great tool is available? the guts consist of mplayer converting a video to a gif -- study this command and read the man page for more information $ mplayer video.flv -ss 00:23 -endpos 6 -vo gif89a:fps=5:output=output.gif -vf scale=400:300 -nosound generates a 6 second gif starting at 23 seconds of play time at 5 fps and a scale of 400x300 start time (-ss)/end time (-endpos) formats: 00:00:00.000 end time should be relative to start time, not absolute. i.e. -endpos 5 == seconds after 0:42 = 0:47 end point play with fps and scale for lower gif sizes the subshell is a solution for the -b flag on youtube-dl which downloads the best quality video, sometimes, which can be various video formats $(ls ${url##*=}*| tail -n1)

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

Clean way of re-running bash startup scripts.

This replaces the current bash session with a new bash session, run as an interactive non-login shell... useful if you have changed /etc/bash.bashrc, or ~/.bashrc If you have changed a startup script for login shells, use $ exec bash -l Suitable for re-running /etc/profile, ~/.bash_login and ~/.profile. edit: chinmaya points out that $ env - HOME=$HOME TERM=$TERM bash -s "exec bash -l" will clear any shell variables which have been set... since this verges on unwieldy, might want to use $ alias bash_restart='env - HOME=$HOME TERM=$TERM bash -s "exec bash -l"'

Lists the supported memory types and how much your board can support.

Recursively remove directory with many files quickly

rsync'ing an empty directory over a directory to be deleted recursively is much faster than using rm -rf, for various reasons. Relevant only for directories with really a lot of files.

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)