# changes hex 0x15 to delete everything to the left of the cursor,
# rather than the whole line
$ echo 'bindkey "^U" backward-kill-line' >> ~/.zshrc
# binds hex 0x18 0x7f with deleting everything to the left of the cursor
$ echo 'bindkey "^X\\x7f" backward-kill-line' >> ~/.zshrc
# adds redo
$ echo 'bindkey "^X^_" redo' >> ~/.zshrc
# reload your .zshrc for changes to take effect
$ source ~/.zshrc