Reload aliases on change automatically without closing the shell window

Question

I have my aliases stored in ~/.zsh_aliases and sourced in ~/.zshrc:

# Access custom aliases in the shell
[ -e "${HOME}/.zsh_aliases" ] && source "${HOME}/.zsh_aliases"

However, when changing the name of an alias, I have to always close the current shell window and open a new one for the change to become active.

Can Zsh automatically reload aliases on change to make them available without having to close the shell window?

Answer 1

You do not actually need to close and reopen your terminal for that, just running source ~/.zsh_aliases (loads the new and changed aliases) or maybe exec zsh (replaces the current shell with a new one) would work, too.

If you really want to re-source ~/.zsh_aliases whenever it is modified, I would suggest adding the following to your ~/.zshrc:

# File containing aliases; 
ALIAS_FILE="${HOME}/.zsh_aliases

reload_aliases () {
    # do nothing if there is no $ALIAS_FILE
    [[ -e ALIAS_FILE ]] || return 1
    # check if $ALIAS_FILE has been modified since last reload
    # the modifier `(:A)` resolves any symbolic links
    if [[ $LAST_ALIAS_RELOAD < $(stat -c %Y ${ALIAS_FILE}(:A)) ]]; then
        # remove all aliases; optional!
        # only do this if all of your aliases are defined in $ALIAS_FILE
        # also affects aliases defined on the command line
        unalias -m '*'
        # load aliases
        source $ALIAS_FILE
        # update date of last reload
        LAST_ALIAS_RELOAD=$(date +%s)
    fi
}

# make reload_aliases to be run before each prompt
autoload -Uz add-zsh-hook
add-zsh-hook precmd reload_aliases

Note, that any changes will only be available on a new prompt. That means, if you modify ~/.zsh_aliases, you need to press at least Enter once in the all terminals for the changes to take effect.

Answer 2

I use an alias, thusly: -

alias vialias='vi ~/.oh-my-zsh/custom/alias.zsh ; source ~/.oh-my-zsh/custom/alias.zsh'

When I run vialias, I edit my aliases, then when I leave vi, the change(s) take effect.