In ghci, when I want to view the help documentation, I type
> :?
The terminal responds with
> :?
Commands available from the prompt:
<statement> evaluate/run <statement>
: repeat last command
...
..
.
but the file is long enough that this beginning of the file immediately scrolls off the page.
In the shell terminal, when viewing e.g. a man page long enough for this scroll-off to occur, the pager program less is used to make scrolling easy and so that viewing can begin at the beginning of the file.
Is there a way to page-view such as with the shell's less from within ghci?
Related
Good Day.
I am a hobby programmer, and am just looking for creative ways to get things done.
In particular, closing a tab or tabs in sublimetext3 through a cmd line method.
The even cooler thing would be, if so, is there a way to decide in cmd which tab to close e.g. 3rd from left/right etc?
In keeping with the idea that this is mostly curiosity and preference than anything else, so creative replies are definitely appreciated as well.
You can execute any command* from the command line, so this is very much possible.
For example, to close the active tab of the most recently used Sublime Text window, you can run subl --command close.
To close a specific tab, for example the 18th tab, which will have index 17 because it is zero-based:
subl --command 'close_by_index {"group": 0, "index": 17}'
(This is assuming bash syntax - for Windows cmd syntax, you may need to do some creative escaping because the command arguments have to be valid JSON and quoted as part of the same argument as the name of the command you want to execute.)
This is exactly the same command that would be run when right-clicking on the tab and picking Close Tab in the context menu. This command can be seen by inspecting Packages/Default/Tab Context.sublime-menu using the built-in View Package File functionality in the Command Palette. You can check this file to see other pre-defined entries like closing all other tabs, or tabs to the right etc.
*: Caveats being if ST is not already running, then it tries to run the command before plugins are loaded.
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).
Is there any way to display the current TTY when using Emacs shell mode? Right now I get around by having tty displayed as part of the prompt but this requires scrolling back
You can display it on the mode line.
Look at the documentation , in elisp manual, section 23.4 -- Mode Line Format. In subsection 23.4.2 there is written how you do it: you write a form that returns the value you are interested about.
`(:eval FORM)'
A list whose first element is the symbol `:eval' says to evaluate
FORM, and use the result as a string to display. Make sure this
evaluation cannot load any files, as doing so could cause infinite
recursion.
I'm using zsh in OS X Terminal.app and for quite a while, I've been longing for a way to jump back and forth between prev/next prompts in the terminal's output.
One convenience with this would be to be able to review (and track errors at) the end of each command's output; eg. when you building stuff from source with ./configure; make; make install. Note: I'm obviously not referring to jumping back and forth in the command-history, but for a way to take a peek at the endings of each command's output.
Has anyone heard of such functionality in the *nix (preferrably also Mac) world? Would it require some sort of OS-centric Terminal plugin, or can it be programmatically done via a shell script which can be tied to a keyboard shortcut? Maybe I'm the only one thinking about this? :)
Edit: Here's an example scenario: Let's say I want to compile and install some program (using standard ./configure && make && make install procedure) and after the make command, I run into some errors. Now, the way I understand it (I may be completely wrong), the crucial error causing the make command to fail usually shows up in the last line(s) in the output, no? Anyway, at this point, I might do something like cat INSTALL to read up on the INSTALL document to check whether there's something I've missed. NOW, if I want to go back to see what the error was, that caused my initial make command to fail, I then have to manually scroll up to that position again, since my cat INSTALL command printed a ton of text after it.
I don't know if this scenario is the most elucidative – but there are many other situations where I wish I could just "jump" back to previous prompt lines and check up on previous command output; whether it was a simple ls command, make, git status, or whatever it was – swapping positions in the window by means of using prompt lines as "bookmark" positions seems an interesting idea to me.
command + left or right goes between tabs in iterm. is this what you are asking?
Emacs has a shell-mode that runs a shell inside the Emacs editor, providing a rich environment of additional commands for navigating and working with shell commands. This includes commands for going to the previous/next prompt, and deleting the output from commands so you can "clean up" and issue another command.
If you aren't familiar with Emacs: to start a shell inside Emacs, run emacs from the shell, then type Esc-x (or Meta-x, if you have "Use option as meta key" enabled in Terminal > Preferences > Settings > [profile] > Keyboard). This will ask for a command to execute. Enter shell.
To see a list of commands you can use in Shell Mode, enter Control-h m. Here are the ones for moving the cursor to the previous/next prompt:
C-c C-n comint-next-prompt
C-c C-p comint-previous-prompt
These commands would also be useful:
C-c C-r comint-show-output
C-c C-o comint-delete-output
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 ⇧.