Bash – Converting bash script to fish

bashfish

I'm trying to add the following bash scripts to fish, yet am having trouble getting the syntax in fish right. Here is the original script:

export MINION_INSTALL=$HOME/minion
export NOTES_HOME=$HOME/Notes
export INBOX=$NOTES_HOME/inbox

if [ -d "$MINION_INSTALL" ] ; then
    export PATH="$MINION_INSTALL:$PATH"
fi

source $MINION_INSTALL/aliases_for_minion

And this is the aliases_for_minion file:

alias mn="minion"
alias icannotfind="minion --open --archive --full $@"
alias newnote="minion --new-note $@"
alias open="minion --open $@"
alias remind="minion --new-note --quick $@"
alias summary="minion --count inbox; minion --list --show-tags=False today; \
    minion --count next; minion --count soon; minion --count someday"

The minion command works fine if I run fish after starting bash.

Any help would be greatly appreciated!

Best Answer

Here's some examples of what this would look like in fish:

set -x INBOX $NOTES_HOME/inbox
if [ -d "$MINION_INSTALL" ]
    set -x PATH $MINION_INSTALL $PATH
end

Note the absence of the quotes, which is especially important in the line that sets PATH. Quoting it would collapse all of the paths in the list to a single entry, which is not what you want.

The aliases are valid in fish, except for the $@ at the end. fish has arguments as $argv, not $@, but more importantly, any arguments are implicitly appended to the alias command. So you can just write:

alias newnote="minion --new-note"

Then, for example, newnote foo bar will become minion --new-note foo bar

If you like, you can verify it with functions newnote, which will show you the function that the alias produced.

Hope that helps!

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bash has special syntax for setting environment variables, while fish uses a builtin. I would suggest writing your .env file like so:

setenv VAR1 val1
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function setenv() { export "$1=$2"; }
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In fish (e.g. config.fish):

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Apparently fish uses ; and for && and () for command substitutions.

So just changing the command to

pacman -Qtdq; and sudo pacman -Rns (pacman -Qtdq)

should work.

Answering the actual question, normally you can get a statement to be executed in Bash simply by redirecting the statement to a bash command's STDIN by any mean (notice that I'm on Zsh, which supports here strings, and that the statement prints the content of a Bash-specific variable):

% <<<'echo $BASH' bash
/bin/bash

However as a general rule I'd suggest to use bash's -c option. For example here strings and pipes don't play too well with multiple commands, here documents will be expanded by the current shell, etc (nevertheless those need to be supported by the current shell).

Overall bash -c seems to be always a safe bet:

bash -c 'pacman -Qtdq && sudo pacman -Rns $(pacman -Qtdq)'

Which for multiple commands becomes something like this:

bash -c '
command1
command2
command3
'

Best Answer

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