Start Emacs.app from CLI

Emacs_starter.pl

#!/usr/bin/perl

# Emacs starter for Emacs mac port

# Thanks to Aquamacs Project and David Reitter

my $args = "";
my $tmpfiles = "";

for my $f (@ARGV) {
  $args .= '"'.$f.'" ';
  $tmpfiles .= '"'.$f.'" ' if (! -e $f);
}

system("touch $args") if ($tmpfiles);
 
system("open -a /Applications/Emacs.app $args");

# delay deletion because AE drag&drop doesn't work with non-existing documents
system("(sleep 3; rm $tmpfiles) &") if ($tmpfiles);
 
exit;

I rewrote this as a shell script and added the capability to accommodate filenames with spaces:

#!/bin/sh

if [ -e '/Applications/Emacs.app' ]; then
  t=()

  if [ ${#@} -ne 0 ]; then
    while IFS= read -r file; do
      [ ! -f "$file" ] && t+=("$file") && /usr/bin/touch "$file"
      file=$(echo $(cd $(dirname "$file") && pwd -P)/$(basename "$file"))
      $(/usr/bin/osascript <<-END
        if application "Emacs.app" is running then
          tell application id (id of application "Emacs.app") to open POSIX file "$file"
        else
          tell application ((path to applications folder as text) & "Emacs.app")
            activate
            open POSIX file "$file"
          end tell
        end if
END
      ) &  # Note: END on the previous line may be indented with tabs but not spaces
    done <<<"$(printf '%s\n' "$@")"
  fi

  if [ ! -z "$t" ]; then
    $(/bin/sleep 10; for file in "${t[@]}"; do
      [ ! -s "$file" ] && /bin/rm "$file";
    done) &
  fi
else
  vim -No "$@"
fi

Since I switched from vi, I can't help but to type vi filename every time, so I saved this script as /usr/local/bin/vi. In the off chance I haven't yet installed Emacs.app, it uses the built in system vim instead.

Thanks @ptb :)

Sorry to ask guys, how can I install this?

@lmartins Paste into a file named emacs (or whatever you want the command to be) in a directory in your path (ahead of the location of the existing emacs command). Then chmod +x /path/to/emacs.

It'd be better to use emacsclient (and kick off Emacs.app as the alternate editor if it's not running already.)

The command open with the argument -a does not need the full application path. It's not useless but if you have installed Emacs in a different location I would consider just to use

system("open -a Emacs $args");

Here's a variation that ensures Emacs.app is launched, waits for it to be ready, and then uses emacsclient to open the file in a GUI frame and wait for edits to be completed.

#!/bin/sh

CLIENT=/Applications/Emacs.app/Contents/MacOS/bin/emacsclient

$(/usr/bin/osascript <<-END
  tell application ((path to applications folder as text) & "Emacs.app")
    activate
  end tell
END
)

while ! "$CLIENT" -e '"pass"' 2>&1 | grep '"pass"' > /dev/null; do
    sleep 0.3
done

if test "$#" -gt 0; then
    exec "$CLIENT" -c $@
fi

Hi @mwolson, thanks for the update. I believe your starter script works for Nextstep port (although I haven't verify that by myself), but it not works for Mac port. Because Emacs Mac port lacks multi-tty support, which means, emacsclient from mac port can only able to create tty frames but not GUI frames.

@ptb Just curious, why do you use a sub-shell to initialize t in your script? Any reason not to use t="" instead?

Edit: After some digging, I see I was misinterpreting the parentheses and mistaking an array assignment for a sub-shell.

Do I need to start server in emacs config before running this? because emacsclient gives me the following error

emacsclient -c nginx.conf
emacsclient: can't find socket; have you started the server?
To start the server in Emacs, type "M-x server-start".

I made some small modifications to the script @ptb provided. This variation is callable with or without file args, and will make emacs visible even if it was previously hidden.

The if [ $# -gt 0] block that handles file args is run in the background (see the closing fi &), but its contents run synchronously with respect to each other. That prevents deleting the tempfiles before they've been visited, with no need for sleep.

#!/bin/sh

emacs_app=/usr/local/opt/emacs-mac/Emacs.app

if [ ! -x $emacs_app ]; then
  echo "Emacs.app not found" >&2
  exit 1
fi

/usr/bin/osascript -e "tell application \"$emacs_app\" to activate" &

if [ $# -gt 0 ]; then
  tempfiles=()

  while IFS= read -r filename; do
    if [ ! -f "$filename" ]; then
      tempfiles+=("$filename")
      /usr/bin/touch "$filename"
    fi

    file=$(echo $(cd $(dirname "$filename") && pwd -P)/$(basename "$filename"))
    /usr/bin/osascript -e "tell application \"$emacs_app\" to open POSIX file \"$file\""
  done <<< "$(printf '%s\n' "$@")"

  for tempfile in "${tempfiles[@]}"; do
    [ ! -s "$tempfile" ] && /bin/rm "$tempfile"
  done
fi &

This will create buffers of any number of existing or non-existing files with or without spaces in their names in a new instance of Emacs.app. emacs_starter file1 file2 file3 ...

#! /usr/bin/env perl
local $" = qq{" "};
my (@have, @havenot);
for (@ARGV) {-e && {push @have, $_} || push @havenot, $_}
system qq{open -a Emacs.app "@have" --args "@havenot"};

If you have an emacs server running, then typing emacsclient file1 file2 file3 ... will use the server.