Bash Oneliners

Curated list of useful bash onliner commands and functions.

Table of Contents

• Files & Directory
• Git
• Network
• System
• Terminal

Files & Directory

List only empty directories and delete safely.

find . -type d -empty -exec rm -i -R {} \;

Find duplicate files in directory using MD5.

find . -not -empty -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find . -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate

Sort disk usage in human-readable format on current directory.

for i in $(echo -e 'G\nM\nK'); do du -hsx *  2>/dev/null | grep '[0-9]'$i | sort -rn; done

Git

Print the list of your Git commits this month.

git log --since='last month' --author="$(git config user.name)" --oneline

Delete all local git branches that have been merged and deleted from remote.

git branch -d $( git branch -vv | grep '\[[^:]\+: gone\]' | awk '{print $1}' | xargs )

Revert files with changed mode, not content.

git diff --numstat | awk '{if ($1 == "0" && $2 == "0") print $3}' | xargs git checkout HEAD

List all authors of a git project.

git log --format='%aN <%aE>' | awk '{arr[$0]++} END{for (i in arr){print arr[i], i;}}' | sort -rn | cut -d ' '  -f2-

Shows a short descriptive information inline including branch details in a coloured log tree.

git log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr)%Cblue - %cn %Creset' --abbrev-commit --date=relative

Network

Get your public IP address.

curl -s http://checkip.dyndns.org | sed 's/[a-zA-Z<>/ :]//g'

System

Show all the startup applications that are hidden in "startup applications".

sudo sed -i "s/NoDisplay=true/NoDisplay=false/g" /etc/xdg/autostart/*.desktop

Quick and dirty way to update system time in Linux if there is any issues with ntp.

sudo date -s "$(wget -qSO- --max-redirect=0 google.com 2>&1 | grep Date: | cut -d' ' -f5-8)Z"

Count the total number of hours of your music in the directory.

find . -print0 | xargs -0 -P 40 -n 1 sh -c 'ffmpeg -i "$1" 2>&1 | grep "Duration:" | cut -d " " -f 4 | sed "s/.$//" | tr "." ":"' - | awk -F ':' '{ sum1+=$1; sum2+=$2; sum3+=$3; sum4+=$4; if (sum4 > 100) { sum3+=1; sum4=0 }; if (sum3 > 60) { sum2+=1; sum3=0 }; if (sum2 > 60) { sum1+=1; sum2=0 } if (NR % 100 == 0) { printf "%.0f:%.0f:%.0f.%.0f\n", sum1, sum2, sum3, sum4 } } END { printf "%.0f:%.0f:%.0f.%.0f\n", sum1, sum2, sum3, sum4 }'

Clear Linux Cache

1. Clear PageCache only

   sync && echo 1 | sudo tee /proc/sys/vm/drop_caches

2. Clear dentries and inodes

   sync && echo 2 | sudo tee /proc/sys/vm/drop_caches

3. Clear PageCache, dentries and inodes

   sync && echo 3 | sudo tee /proc/sys/vm/drop_caches
   

Terminal

Get top 10 used commands from history.

history | awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | grep -v "./" | column -c3 -s " " -t | sort -nr | nl |  head -n10

Print all the supported terminal colours and their reference code to use with tput.

( x=`tput op` y=`printf %$((${COLUMNS}-6))s`;for i in {0..256};do o=00$i;echo -e ${o:${#o}-3:3} `tput setaf $i;tput setab $i`${y// /=}$x;done; )