How to set shell output to a particular mode? - emacs

I'm starting to use shell-mode more often in emacs and what I'd really like is for grep output and other grep-like-output (gcc, etc) to recognize source code line references and allow me to jump to source lines in the output. Is there a way to apply grep-mode to a single Output Group?

No, emacs modes are whole-buffer.
However, you can narrow to the last output, turn on grep-mode, and widen and restore comint-mode when done.
Nevertheless, the grep command (and compile for gcc) are more than adequate; use them instead of running gcc and grep in the *shell* buffer.

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

Emacsclient keep buffers after closing

In emacsclient, is there a way to open a file from the command line such that its buffer will remain open on the server after I close the client?
Alternatively, is there a command I can run from in a client to tell it to effectively detach from a buffer, so that the buffer does not get killed when the client exits?
Normally when closing emacsclient either with C-x C-c or C-x #, the buffer(s) associated with that client get killed, which is usually convenient behavior, but sometimes I would like for buffers to stay alive after closing. So far the only way I have found to accomplish this is to run the client without specifying any files, then visit them with C-x C-f, but I'm wondering if there's a better way to do this.
You should be able to do this by using the -n option. That means that it won't wait for you to "finish" the buffer and it'll just stay in the buffer list. I use this with emacsclient myself.
So, one option is to use emacsclient's eval command line option to run a lisp command to find the file you want.
emacsclient -c -e '(find-file "my_file")'
Obviously this is a lot more to type than the command sequence emacsclient -c, C-x C-f, my_file, but it could pretty easily be wrapped in a script that takes an extra argument to tell it whether to just choose the file or use find-file.
Someone more well versed in elisp than I could probably just add the option directly into emacs.
According the info manual, if you never want to kill emacsclient buffers, when you're done with them, you can customise the server-kill-new-buffers variable (more information at C-h v server-kill-new-buffers).
For you use-case, depending on how often you want the buffers killed or not, you could set the above variable to nil and then manually kill the buffers that you do want killed.

Emacs: How to read command help just as one would read Man pages?

It's nice to run M-x man foo for command foo within Emacs. It's then possible to navigate easily within the man page and to find details quickly.
When the help of a command (such as git) produces limited output, one can just use a terminal instead of emacs.
But occasionally, a command (such as aws help—run in a terminal) produces extensive output. Yet the output is not compatible with the emacs Man mode. An option is to use M-x shell within emacs, but that will not display the page at once. It will report "WARNING: terminal is not fully functional" and require pressing a key endlessly until the complete help appears, or, for Emacs 25, "Could not find executable named 'groff'".
What is a good way to read long manual pages produced by commands within emacs?
I just ran into this exact problem a few days ago.
Type escape + ! then type (for example) “aws ec2 help”. This brings the help text into a new buffer called Shell Command Output, with all of the control-h characters, etc.
Switch to the new buffer with control-x then lowercase ‘o’ (for other buffer)
Type escape + lowercase ‘x’ to run an emacs function, then type ‘man’ and hit Enter. It will prompt for man page entry and default to EC2, just hit Enter. In my case, it displays an error in the status line, “error in process sentinel: Can’t find the EC2 manpage”.
However, the “man page” functions are now available, so now (in that buffer)you can type escape + x and run the function Man-fontify-manpage. The page should now look like a nice man page with bold, etc.
You can then rename the buffer (escape + x then something like ec2) so the buffer isn’t replaced if you run another shell command.
I you just want the output in a buffer, you can simply use:
M-! aws help RET
If you want the output in a shell buffer, you can do git help commit | cat (so no more "terminal is not fully functional").
Probably you can do M-! aws help | cat RET also. I do not have aws, but hopefully the piping will remove the escape characters if aws output formatting is done right. You should try also TERM=dumb aws help. Any command should know better than using fancy output when TERM is set to dumb. If aws is dumb that way itself, you could pipe its output to something that filters out control characters -- try this
For forcing man mode in an arbitrary buffer, M-x Man-mode (yes, uppercase). I am not sure if that will play nice with aws's output.
By the way, for git I suppose you know you can do man git-commit (or man git-any_git_command, in general), so you have a nice alternative to git help when using emacs (output of help and man page is the same).

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").

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 ⇧.