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Author: byte-cook

README.md

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+# Bash Alias and Function
+
+This project contains useful bash aliases and functions. Bash aliases are essentially shortcuts that save you from having to remember long commands and save you a lot of typing when working on the command line.
+
+To make the alias or function persistent you need to declare it in the ~/.bashrc file. If you want to make your ~/.bashrc more modular, you can store your aliases in a separate file. Some distributions, such as Ubuntu and Debian, include a ~/.bash_aliases file that is referenced in ~/.bashrc.
+
+Pick the shortcuts you are interested in and copy the code into one of the files mentioned above. 
+
+## Run alias commands as root
+
+Alias definition:
+```
+sudo='sudo '
+```
+
+Usage: 
+```
+sudo <youralias>
+```
+
+How it works:
+If the last character of the alias value is a blank, then the next command word following the alias is also checked for alias expansion. 
+See <https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html?ref=linuxhandbook.com#Aliases>.
+
+## Mount iso file
+
+Alias definition:
+```
+function mount.iso() {
+    # $1: the iso file
+    if [ $# -eq 1 ]; then
+        sudo mkdir -p /media/iso 
+        sudo mount -o loop -t iso9660 "$1" /media/iso
+    else
+        echo Usage: mount.iso \<iso-file\>
+    fi
+}
+function umount.iso() {
+    sudo umount /media/iso
+    sudo rmdir /media/iso
+}
+```
+
+## Convert video files
+
+Convert MP4 files to MP3 files:
+```
+alias convert.mp42mp3='for f in *.mp4; do ffmpeg -i "$f" "${f%.mp4}.mp3"; done'
+```
+
+Convert MOV files to MP4 files
+```
+alias convert.mov2mp4='for i in *.mov; do ffmpeg -i "$i" -vcodec h264 -crf 30 -acodec aac "${i%.mov}_new.mp4"; done'
+```
+
+Convert high quality MP4 files to MP4 files with lower quality:
+```
+alias convert.mp42mp4='for i in *.mp4; do ffmpeg -i "$i" -vcodec h264 -crf 30 -acodec aac "${i%.mp4}_new.mp4"; done'
+```
+
+## Download m3u8 file
+
+```
+function download.m3u8 {
+    # $1: m3u8 url
+    # $2: output filename
+    if [ $# -eq 1 ]; then
+        cd ~/Downloads
+        ffmpeg -protocol_whitelist file,http,https,tcp,tls,crypto -i "$1" -c copy "$2"
+    else
+        echo Usage: download.m3u8 \<m3u8-url\> \<output-file\>
+    fi
+}
+```
+