Sometimes I use multiline commands in zsh:
❯ echo \
> a \
> multiline \
> command
When editing the command after pulling it from a history search, I can change the content of individual lines. However, I can't figure out how to insert another line:
# I want to insert another line after "multiline"...
❯ echo \
> a \
> multiline \ # but hitting <return> here just runs the command, even though there's a backslash at the end of the line
> command
How can I insert a newline in the middle of a multiline command pulled from history?
You can use self-insert-unmeta to bind Alt+Return to insert a literal newline without accepting the command:
bindkey '^[^M' self-insert-unmeta
To use your example: Hitting Alt+Return at the cursor position (#)
% echo \
a \
multiline \#
command
will get you this:
% echo \
a \
multiline \
#
command
This works not only when editing history, but also when typing commands. So you can prepare several commands in a script like fashion and accept them with a single Return.
For example pressing Alt+Return instead of # in this example:
% echo command 1#
echo command 2#
echo command 3
will do the same thing as the command echo command 1; echo command 2; echo command 3 and produce this output:
command 1
command 2
command 3