bashoneliners.com

Welcome to bashoneliners.com, a growing collection of practical and well-explained Bash one-liners, snippets, tips and tricks. We review and improve every contributed one-liner to make sure it is of high quality: useful, easy to read, follows best practices, with clear, detailed, accurate explanation. These one-liners should help you automate tasks, troubleshoot problems, whether it be in system administration, file management, networking or programming.

0

Watch a mashup of many video files

L=5; while true; do; readarray -t paths < <(find . -type f -print | shuf -n 1); for i in "${!paths[@]}"; do; path=${paths[i]}; if ffprobe -i "$path" -show_entries format=duration -v quiet -of csv="p=0" > /dev/null; then; N=$(ffprobe -i "$path" -show_entries format=duration -v quiet -of csv="p=0"); D=${N%.*}; P=$((D / 100 * 25)); R=$((1 + RANDOM % D - P * 2)); S=$((P + RANDOM % R)); W=$((R / 4)); LEN=$((1 + RANDOM % L)); mpv "$path" --start="$S" --length="$LEN" --fs &> /dev/null; W=$(bc <<< "$LEN - 0.5"); sleep "$W"; unset 'paths[i]'; fi; done; done

July 6, 2023krypniok

0

While loop to pretty print system load (1, 5 & 15 minutes)

while :; do date; awk '{printf "1 minute load: %.2f\n", $1; printf "5 minute load: %.2f\n", $2; printf "15 minute load: %.2f\n", $3}' /proc/loadavg; sleep 3; done

September 5, 2018bashoneliners

0

While loop to pretty print system load (1, 5 & 15 minutes)

while [ 1 == 1 ]; do  cat /proc/loadavg | awk '{printf "1 minute load: %.2f\n", $(NF-5)}' && cat /proc/loadavg |awk '{printf "5 minute load: %.2f\n", $(NF-3)}' && cat /proc/loadavg |awk '{printf "15 minute load: %.2f\n", $(NF-2)}'; sleep 3; date; done

August 30, 2018peek2much3

1

Have script run itself in a virtual terminal

tty >/dev/null || { urxvt -e /bin/sh -c "tty >/tmp/proc$$; while test x; do sleep 1; done" & while test ! -f /tmp/proc$$; do sleep .1; done; FN=$(cat /tmp/proc$$); rm /tmp/proc$$; exec >$FN 2>$FN <$FN; }

March 9, 2018openiduser111

2

Big CSV > batches > JSON array > CURL POST data with sleep

cat post-list.csv | split -l 30 - --filter='jq -R . | jq --slurp -c .' | xargs -d "\n" -I % sh -c 'curl -H "Content-Type: application/json" -X POST -d '"'"'{"type":1,"entries":%}'"'"' http://127.0.0.1:8080/purge-something && sleep 30'

March 7, 2018pratham2003

1

Download a file from a webserver with telnet

(echo 'GET /'; echo; sleep 1; ) | telnet www.google.com 80

December 22, 2014bashoneliners

7

Display the number of connections per IP to port 80

while true; do clear; date; echo; echo "[Count] | [IP ADDR]"; echo "-------------------"; netstat -n | grep ':80\>' | awk '! /LISTEN/ {print $5}' | cut -d: -f1 | uniq -c; sleep 5; done

April 9, 2014cesp

1

Define an own watch(1)-like function

watch () { interrupted=false; trap "interrupted=true" INT; while ! $interrupted; do $*; sleep 1 || interrupted=true; done; }

November 14, 2012ulidtko

0

Run command multiple times with a for loop and a sequence expression

for i in {1..10}; do date; sleep 1; done

August 19, 2012bashoneliners

0

Alert me by email when a disconnected or unreachable server comes back online

while ! ping -c1 the_host_down; do sleep 1; done && date | mail -s 'the host is back!' me@example.com

October 10, 2011janos