Inom TurdikulovBash (Unix shell)
Bash is a Unix shell and command language written by Brian Fox for the GNU Project as a free software replacement for the Bourne shell. First released in 1989, it has been used as the default login shell for most Linux distributions. Bash was one of the first programs Linus Torvalds ported to Linux, alongside GCC.
— Wikipedia
Personally, I use Zsh as my default shell and interactive command interpreter, but sometimes I use and write scripts written in Bash (for portability).
Cheat sheet:
Snippets
Uppercase first letter of filenames:
for i in *; # process every file in current directory
do new=`echo "$i" | sed -e 's/^./\U&/'`; # replace first char by a capitalized version
mv "$i" "$new";
done;