How to force emacs to use \n instead of \r\n - emacs

I have to use windows to write some shell scripts. I decided to use emacs, but I get a weird error when running the script:
/bin/bash^M: bad interpreter: No such file or directory
Correct me if I'm wrong, but that looks like the shebang ends in \r\n instead of just \n. How can I tell emacs to only write \n? I'm in Shell-script major mode. It's quite surprising this isn't fixed by default.

As Jürgen mentioned, you need to use the set-buffer-file-coding-system. You can say
(set-buffer-file-coding-system 'unix)
and stick that into a function inside the find-file-hook so that it will set it for all the buffers you open. Alternatively, you can put it inside the write-file-hook list so that the file-coding-system is set properly before you dump the file to disk.
For a simpler way out, if you're using the GUI version of Emacs, you can click on the 3rd character in the modeline from the left. It's to toggle between eol formats.

Use:
set-buffer-file-coding-system
(should be bound to a key-sequence) before saving the file.

Related

Shell script mode automatically at each emacs start

Each time when I edit bash script I type a command M-x shell-script-mode. And then I get nice shell code higlighting. How to get it automatically each time I start emacs so I do not have to type the command. When I added (shell-script-mode) to init.el it did not help.
You can set the default major mode to be whatever you want by adding
(setq-default major-mode 'shell-script-mode)
to your init file. That will ensure that any newly created buffer will be in shell-script-mode unless its mode is specified otherwise (e.g. through auto-mode-alist). Whether it's a good idea or not, I don't know: I probably would not want that to be my default setting - but to each her/his own.
One of the simplest ways to have Emacs set the desired mode for a buffer editing a file is to include a special comment in the first line of that file, e.g. for a shell script your first line might be:
# -*-sh-*-
For scripts it is also common, or and often even required, to have an interpreter file comment on the very first line of the file, which of course would preclude having an Emacs mode comment, so Emacs also looks for interpreter file comments and associates those with a major mode, so the first line of your shell script might be:
#!/bin/sh
There are a number of other ways to tell Emacs how to set the buffer mode when visiting a file. See, for example, Emacs Manual: Choosing File Modes

Open file from Emacs terminal without find-file

If I'm in a term-mode buffer and there is a file path displayed, how would I go about making the path "clickable", opening the file in a new buffer? It doesn't have to be mouse-clickable, in fact I'd prefer a key binding that works when the point is on the file path. Other than the common case of using ls, this function could be used when viewing a log file. Some debug info contains the file path and line number. Something like lib/library.rb:34 for example. Ideally, Emacs could open a new buffer and move the cursor to line 34.
The short answer is: don't work against Emacs. Let Emacs work for you.
While you can use find-file-at-point or put together something yourself, you will be much better off running make, grep and other stuff which prints "dir/file:pos" using M-x compile or M-x grep.
If you need to interact with your program which prints "dir/file:pos", you can pass a prefix argument to compile and the compilation buffer will be interactive.
If you have an arbitrary program whose output starts with "dir/file:pos", e.g., rails server, all you need to do is run it as (grep "rails server").

emacs makefile-mode for Makefile.include

I use file named Makefile.include as a GNU makefile. I am trying to get emacs use the makefile-mode to use for this file. Alt-X makefile-mode works. Is there a way to tell emacs to use this major mode for this file right after opening automatically?
I tried putting
# _*_ mode: makefile; _*_
in the file but that does not appear to have the right effect. Btw I could not find the list of allowed strings one can use after mode:, so I tried BDSmakefile and some other variations as well.
Thanks.
See this question: Setting auto-mode-alist in emacs, and use the pair ("Makefile\\.include\\'" . makefile-mode).

How can I script vim to run perltidy on a buffer?

At my current job, we have coding-style standards that are different from the ones I normally follow. Fortunately, we have a canned RC file for perltidy that I can apply to reformat files before I submit them to our review process.
I have code for emacs that I use to run a command over a buffer and replace the buffer with the output, which I have adapted for this. But I sometimes alternate between emacs and vim, and would like to have the same capabilities there. I'm sure that this or something similar is simple and had been done and re-done many times over. But I've not had much luck finding any examples of vim-script that seem to do what I need. Which is, in essence, to be able to hit a key combo (like Ctrl-F6, what I use in emacs) and have the buffer be reformatted in-place by perltidy. While I'm a comfortable vim-user, I'm completely clueless at writing this sort of thing for vim.
After trying #hobbs answer I noticed that when filtering the entire buffer through perltidy the cursor returned to byte 1, and I had to make a mental note of the original line number so I could go back after :Tidy completed.
So building on #hobbs' and #Ignacio's answers, I added the following to my .vimrc:
"define :Tidy command to run perltidy on visual selection || entire buffer"
command -range=% -nargs=* Tidy <line1>,<line2>!perltidy
"run :Tidy on entire buffer and return cursor to (approximate) original position"
fun DoTidy()
let l = line(".")
let c = col(".")
:Tidy
call cursor(l, c)
endfun
"shortcut for normal mode to run on entire buffer then return to current line"
au Filetype perl nmap <F2> :call DoTidy()<CR>
"shortcut for visual mode to run on the current visual selection"
au Filetype perl vmap <F2> :Tidy<CR>
(closing " added to comments for SO syntax highlighting purposes (not required, but valid vim syntax))
DoTidy() will return the cursor to its original position plus or minus at most X bytes, where X is the number of bytes added/removed by perltidy relative to the original cursor position. But this is fairly trivial as long as you keep things tidy :).
[Vim version: 7.2]
EDIT: Updated DoTidy() to incorporate #mikew's comment for readability and for compatibility with Vim 7.0
My tidy command:
command -range=% -nargs=* Tidy <line1>,<line2>!
\perltidy (your default options go here) <args>
If you use a visual selection or provide a range then it will tidy the selected range, otherwise it will use the whole file. You can put a set of default options (if you have any) at the point where I wrote (your default options go here), but any arguments that you provide to :Tidy will be appended to the perltidy commandline, overriding your defaults. (If you use a .perltidyrc you might not have default args -- that's fine -- but then again you might want to have a default like --profile=vim that sets up defaults only for when you're working in vim. Whatever works.)
The command to filter the entire buffer through an external program is:
:%!command
Put the following in ~/.vimrc to bind it to Ctrl-F6 in normal mode:
:nmap <C-F6> :%!command<CR>
For added fun:
:au Filetype perl nmap <C-F6> :%!command<CR>
This will only map the filter if editing a Perl file.
Taking hobbs' answer a step further, you can map that command to a shortcut key:
command -range=% -nargs=* Tidy <line1>,<line2>!perltidy -q
noremap <C-F6> :Tidy<CR>
And another step further: Only map the command when you're in a Perl buffer (since you probably wouldn't want to run perltidy on any other language):
autocmd BufRead,BufNewFile *.pl,*.plx,*.pm command! -range=% -nargs=* Tidy <line1>,<line2>!perltidy -q
autocmd BufRead,BufNewFile *.pl,*.plx,*.pm noremap <C-F6> :Tidy<CR>
Now you can press Ctrl-F6 without an active selection to format the whole file, or with an active selection to format just that section.
Instead of creating a new keyboard shortcut, how about replacing the meaning of the = command which is already in people's finger memory for indenting stuff? Yes, perlcritic does more than just indent but when you use perlcritic anyways, then you probably don't want to go back to the inferior "just indent" = command. So lets overwrite it!
filetype plugin indent on
autocmd FileType perl setlocal equalprg=perltidy
And now we can use = just like before but with the added functionality of perlcritic that goes beyond just indenting lines:
== run perlcritic on the current line
5== run perlcritic on five lines
=i{ Re-indent the 'inner block', i.e. the contents of the block
=a{ Re-indent 'a block', i.e. block and containing braces
=2a{ Re-indent '2 blocks', i.e. this block and containing block
gg=G run perlcritic on the entire buffer
And the best part is, that you don't have to learn any new shortcuts but can continue using the ones you already used with more power. :)
I'm used to select text using line oriented visual Shift+V and then I press : an I have !perltidy -pbp -et4 somewhere in history so I hit once or more up arrow ⇧.

Why isn't return bound to newline-and-indent by default on emacs

I have tried emacs on and off for a while now and every time I start emacs, I go through the same routine. Customizing. The first one is binding return to newline-and-indent. (g)Vim does this by default. Showing matching parenthesis is also done by default on (g)Vim. It is grea that I can customize emacs to my heart's content but why doesn't emacs have nice and easy defaults? For reference, I am now using Emacs 23 on a RHEL5 box.
Probably because RMS didn't want it, that and because changing long-standing defaults is just an issue of politics. Like vi, Emacs has a hard-core following and basic changes like these are minefields.
Note: if you saved your customizations, then you wouldn't have to re-do them every time...
To have those nice and easy defaults, install Emacs Starter Kit. It enables by default a bunch of useful and convenient features make even the advanced Emacs users more productive.
Otherwise, as TJ pointed out, Emacs Customization Mode (type M-x customize) allows you to save permanently any of the settings. You can even store them in a separate file from your dotemacs―(setq custom-file "~/.emacs-custom.el")―so you can use it in every computer you work on.
The title of your question doesn't really reflect what your question is (and has been answered by Trey and Torok), but I'll tell you why I like it being bound to just newline: useless whitespace. Say you are nested inside a conditional in a function etc. and hit return a couple times to leave a blank line. The blank line now has a bunch of space chars on it. Yes, you can (and I do) remove trailing whitespace before saving, but I also have visual whitespace mode on and I can see it there taunting me.