Collection of useful Shell commands

commands.sh

# This helps to generate gif from any video file.
ffmpeg -i example.mov -ss 0 \
  -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" \
  -loop 0 output.gif
  
# To stitch multiple videos together
# Ref: https://stackoverflow.com/a/7582140/2849127
ffmpeg -i big.avi -vf "movie=small0.avi [small0]; [in][small0] overlay=10:10 [tmp];\
                       movie=small1.avi [small1]; [tmp][small1] overlay=30:10 [out]" out.avi

# Command to download file using aria2c, which requires Auth Token for Download validation
aria2c \
  --header "Host: {host}" \
  --header "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" \
  --header "Upgrade-Insecure-Requests: 1" \
  --header "Cookie: {Token}" \
  --header "User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Firefox/91.0" \
  --header "Accept-Language: en-us" -x 16 -s 16 {URL} 
  
  
# RnR (Replace Names Recursively)
# Dry Run
rnr -r '(?P<name>.*?)\.(?P<ext>(css|scss))' '${name}.module.${ext}' ./*
# Force to commit renaming
rnr -r -f '(?P<name>.*?)\.(?P<ext>(css|scss))' '${name}.module.${ext}' ./*


############
#
# Helpful Git commands, that are not used frequently.
#
############

# Log commits since X date till Y date.
git log --since='Oct 20 2022' --until='Oct 25 2022'


########################## Convert Image to PDF ##################################

i=150; convert aadhaar-front-bw.jpg -compress jpeg -quality 70 \
      -density ${i}x${i} -units PixelsPerInch \
      -resize $((i*827/100))x$((i*1169/100)) multipage.pdf
      
########################## Helpful Docker Commands ##################################

# Remove any image with tag:
docker rmi image-name:latest

# Get a list of all Docker images
docker images --format '{{.ID}}:{{.Repository}}:{{.Tag}}'

# Get a list of all images linked to all running Docker containers
docker ps --format '{{.Image}}'