Pipe Vim buffer to stdout

Question

I'd like to use Vim in the middle of a pipe. This existing post looks like what I'd like to do, except I was hoping to do it without Python's help -- only with bash. [It it helps, the environment is the bash shell in the Terminal IDE app on Android.]

Please, I know how to pipe a buffer through a command from inside Vim. That's great, but not what I want here. I want to exit Vim and pass the active buffer to stdout.

FWIW, I also know how to pass another command into Vim as input. Again, that's not what I'm trying to get here.

Answer 1

Take a look at vipe which is part of moreutils. It allows you to use any editor as part of a pipe.

 ls -al | vipe | less

To use it with vim just make sure to set it as your default editor in your bashrc or cshrc or whatever shell you use.

 EDITOR=vim

UPDATE: If you want a bash only solution you could use a script like this

 #!/bin/bash
 # create temporary file
 TMPFILE=`mktemp /tmp/vipe.bashXXXXXXXX`
 cat > ${TMPFILE}
 vim ${TMPFILE} < /dev/tty > /dev/tty
 cat ${TMPFILE}
 rm ${TMPFILE}

For a more portable version please replace

 vim ${TMPFILE}

with

 ${EDITOR} ${TMPFILE}

Answer 2

To print buffer to shell standard output, vim needs to start in Ex mode, otherwise it'll open "normal" way with its own window and clear any output buffers on quit.

Here is the simplest working example:

$ echo foo | vim +%p -escq /dev/stdin
foo

which is equivalent to:

$ echo foo | vim -es '+%print' '+:q!' /dev/stdin
foo

^{Special file descriptor to standard input needs to be specified (/dev/stdin) in order to prevent extra annoying messages.}

And here are some examples with parsing strings:

$ echo This is example. | vim '+s/example/test/g' '+%p' -escq! /dev/stdin
This is test.
$ echo This is example. | vim - '+s/example/test/g' '+%p' -escq!
Vim: Reading from stdin...
This is test.

---

Related:

• How to edit files non-interactively (e.g. in pipeline)? at Vim SE
• How to write buffer content to stdout? at stackoverflow SE

Answer 3

You cannot simply put vim inside a pipe, because then Vim cannot display its UI.

ls | vim - | more # Does not work

One way to solve this is to use gvim -f - inside the pipe, as it opens in a separate window. You need to write the file via :w >> /dev/stdout and then :quit!.

Alternatively (and the only way in a console-only non-graphical environment), you could write your own script / function vimAndMore that takes the command that should be following vim in the pipe as an argument, and goes like this:

vimAndMore()
{
    TMPFILE=/tmp/pipecontents

    # Slurp stdin into the temp file.
    cat - > "$TMPFILE" || exit $?

    # Reconnect stdin to the terminal, so that Vim doesn't complain with "Warning:
    # Input is not from a terminal", and the terminal is kept intact.
    exec 0</dev/tty

    # Launch the editor.
    "${EDITOR:-vim}" "$TMPFILE" || exit $?

    # Carry on with the pipe.
    cat "$TMPFILE" | exec "$@"

    rm "$TMPFILE"
}

And change the pipe to this:

ls | vimAndMore | more