How can I augment an existing set of syntax rules for a filetype in `vim` without root? - vim

Suppose I wanted to define a new keyword in C called Foo. I do not have root on the system, so I cannot modify the file /usr/share/vim/vim74/syntax/c.vim.
I tried to add the following at the bottom of my .vimrc, but it had no effect at all.
In particular, when I edit a file called Main.c and write Foo, that word is not highlighted the way int is.
syn keyword cType Foo
What is the correct way to augment existing syntax highlighting rules in vim?

Here's the VIM documentation on how to add to existing syntax.
ADDING TO AN EXISTING SYNTAX FILE *mysyntaxfile-add*
If you are mostly satisfied with an existing syntax file, but would like to
add a few items or change the highlighting, follow these steps:
1. Create your user directory from 'runtimepath', see above.
2. Create a directory in there called "after/syntax". For Unix:
mkdir ~/.vim/after
mkdir ~/.vim/after/syntax
3. Write a Vim script that contains the commands you want to use. For
example, to change the colors for the C syntax:
highlight cComment ctermfg=Green guifg=Green
4. Write that file in the "after/syntax" directory. Use the name of the
syntax, with ".vim" added. For our C syntax:
:w ~/.vim/after/syntax/c.vim
That's it. The next time you edit a C file the Comment color will be
different. You don't even have to restart Vim.
You can get there by :help mysyntaxfile-add

Related

How to add words to vim coloring in C/C++ mode?

I notice that in C/C++ mode, comments such as TODO XXX and FIXME get special color marking.
How can I add the word HACK to this list of words to be marked in the same way?
I tried adding the following to my ~/.vimrc, but it didn't work:
syn keyword cTodo contained TODO FIXME XXX HACK
I would advise against directly modifying the original syntax file; you then have to maintain your version whenever the original changes (e.g. after a Vim upgrade). For these small syntax enhancements, the place is in the ~/.vim/after/syntax/c.vim file, which is sourced after the original syntax. The line would be
syn keyword cTodo contained HACK
You need to modify the syntax file. Typically, it is in /usr/share/vim/vim72/syntax, and the file you want is c.vim and cpp.vim. You will see a line syn keyword cTodo contained followed by a list of words that are considered under the Todo label for coloring. You can add your word there, or make your own keyword, but adding your own keyword would mean adding your keyword to the coloring file as well.
For user only changes, make a directory ~/.vim/syntax. Copy the c.vim and cpp.vim files there, and edit as necessary.
Second edit: Decided to look further, and it appears you can just add to a current syntax file, but I haven't tried it. Add your one line you added to your .vimrc to a file in ~/.vim/after/syntax

Adding syntax highlighting for latex plugin in vim

I am using a package called outlines for LaTeX. It adds commands such as \1 \2 \3 etc.
They are not highlighted by default in vim. So, I created a file called tex.vim in my .vimrc/syntax folder, and put this in the file:
:syn match outline /\\[1-9]/
hi link outline Label
This works only at the top level, not within a block. In other words, it works before my \begin{document}, but not between \begin{document} and \end{document}.
This is pretty much useless. How can I get vim to recognize the syntax, regardless of where it appears in the document?
You need to find the syntax group or cluster defined by the Tex syntax, and use contained containedin=..., but in your case, there is already a syntax group for statements, it's just that it doesn't include numbers. Therefore, you can just piggyback on the existing group and only add matching for numbers:
:syn match texStatement /\\\d/

.vimrc TAGS command errors

I use etags with vim on linux for source(*.c, *.h) code browsing. I have created a TAGS file bu giving command :
etags --members *.c *.h
TAGS file gets created but when I start browsing say one of the source files named 1.c which has a C structure variable defined and used in one of its function definitions(The structure name is a typedef in some other 1.h file). I open the file 1.c in vim and then I do CTRL - ] by placing cursor on that struct type, etags does not browse to the header file 1.h which has declaration of this structure.
This only happens when i have below line in my .vimrc, when i comment below two lines, etags based source browsing works fine.
set TAGS=./TAGS;$HOME
set tags=./tags;$HOME
I am trying to tell vim where to locate the TAGS file. starting from current folder till my home dir. What is incorrect here?
What is the correct syntax for above command?
Also does ctags/etags browsing with vim, show from where all a given function is called from?
If yes, what is the command to see that?
Locating tags file
Vim's settings are case-sensitive so set TAGS= is invalid. You must use set tags= in lowercase.
Vim will stop at the first match so you can't really expect it to search for a tag in tags and TAGS. These files can be searched in turn with:
set tags=./tags,./TAGS;$HOME " 1. tags, 2. TAGS, 3.… until $HOME
Also, search is not performed by etags, it's done by Vim itself.
Jumping to function calls
No, ctags and etags only index declarations. To jump to usage you'll need cscope

extend/modify vim highlighting for all filetypes at once?

How do I extend/modify vim highlighting for all filetypes at once?
I have certain relatively simple patterns which I'd like highlight differently, that can occur in any filetype. So rather than adding something like the below to every conceivable filetype I might use (~/.vim/syntax/python.vim, .../css.vim, .../html.vim, ...) is there some way I can define it once for all filetypes?
syn match SpecialComment "#[#\-+].*" containedin=Comment
syn match Comment "\* .*$"hs=s+1 containedin=SpecialComment
update:
As suggested I saved my changes to ~/.vim/after/filetype.vim, with the result that it works in Cream but not stock Gvim or Vim. The actual code I'm using here, a sample python file to test against here, and the desired result:
You could try putting those two lines in ~/.vim/after/filetype.vim. That should get sourced after any of the top level syntax files. It's possibly not the 'correct' place to put it, but it should work.
filetype.vim seems to be sourced BEFORE the syntax files, so it gets overwritten by the default syntax file. Therefore, I'd recommend you create a new file called something like:
~/.vim/after/common_syntax.vim
with the highlight lines that you're interested in. Then, add this to ~/.vim/after/filetype.vim:
if !exists("after_autocmds_loaded")
let after_autocmds_loaded = 1
au BufNewFile,BufRead * source ~/.vim/after/common_syntax.vim
endif
This will cause the file to be sourced once the file has been read.
P.S. Responding to the comment in your sample code: "why can't we use plain ol 'comment' group instead of 'pythoncomment' etc. ?", it's because the syntax highlight group is pythonComment, which is merely coloured in the same way as Comment. If your syntax is unique enough for it not to be a problem, you could just do containedin=ALL. If it is close, but not quite unique, you could do containedin=ALLBUT,conflictgroup where conflictgroup is the highlight group you want to steer clear of.

How to switch between multiple vim configurations with a command or local vimrc files?

I work in several groups, each of which has its own tab/indentation/spacing standards in C.
Is there a way to have separate selectable VIM configurations for each so, when I edit a file, either:
I do something like set group=1 to select a configuration
a local .vimrc that lives in the working directory is used to set the configuration automatically
I have this in $HOME/.vimrc:
if filereadable(".vim.custom")
so .vim.custom
endif
This allows me to put a .vim.custom file in every directory to load commands and options specific to that directory. If you're working on multiple projects that have deep directory structures you might need something more sophisticated (e.g. walk up the directory tree until a .vim.custom is found), but the same basic idea will work.
UPDATE:
I now do something like this in order to read a .vim file from the same directory as the file I'm editing, regardless of what the current directory is.
let b:thisdir=expand("%:p:h")
let b:vim=b:thisdir."/.vim"
if (filereadable(b:vim))
execute "source ".b:vim
endif
In Summary
There are a few ways to do this, of which most have been suggested, but I thought I'd summarise them with two extra ones:
Per-directory vimrc - has the disadvantage that Vim must be started in the right directory: if your project is in ~/project1 and you have ~/project1/.vim.custom and do cd ~ ; vim project1/file.c, the custom settings won't be found.
Modelines - very effective, but has the disadvantage of needing to add them to all files (and remember to add them to new files)
Directory specific autocommands - this is very effective
Scan for a specific header in the file (see below) - this is the one I've used most in the past where working for different companies or on clearly named projects
Per-directory vimrc that's checked when the file is opened (see below). Another fairly easy one to implement, especially if your project code is all in one place.
Scanning for a Header
In a lot of organisations, there's a standard header (with a copyright notice and project name etc) at the top of every source file. If this is the case, you can get Vim to automatically scan the first (e.g.) 10 lines of the file looking for a keyword. If it finds it, it can change your settings. I've modified this to make it simpler than the form I use (which does lots of other things), but create a ~/.vim/after/filetype.vim (if you don't have one yet) and add something like this:
au FileType * call <SID>ConfigureFiletypes(expand("<amatch>"))
" List of file types to customise
let s:GROUPNAMETypes = ['c', 'cpp', 'vhdl', 'c.doxygen']
func! <SID>CheckForGROUPNAMECode()
" Check if any of the first ten lines contain "GROUPNAME".
" Read the first ten lines into a variable
let header = getline(1)
for i in range(2, 10)
let header = header . getline(i)
endfor
if header =~ '\<GROUPNAME\>'
" Change the status line to make it clear which
" group we're using
setlocal statusline=%<%f\ (GROUPNAME)\ %h%m%r%=%-14.(%l,%c%V%)\ %P
" Do other customisation here
setlocal et
" etc
endif
endfunc
func! <SID>ConfigureFiletypes(filetype)
if index(s:GROUPNAMETypes, a:filetype) != -1
call <SID>CheckForGROUPNAMECode()
endif
endfunc
Whenever a file of any type is opened and the file type is set (the au FileType * line), the ConfigureFiletypes function is called. This checks whether the file type is in the list of file types associated with the current group (GROUPNAME), in this case 'c', 'cpp', 'vhdl' or 'c.doxygen'. If it is, it calls CheckForGROUPNAMECode(), which reads the first 10 lines of the file and if they contain GROUPNAME, it does some customisation. As well as setting expandtabs or whatever, this also changes the status bar to show the group name clearly so you know it's worked at a glance.
Checking for Configuration When Opening
Much like JS Bangs' suggestion, having a custom configuration file can be useful. However, instead of loading it in vimrc, consider something like this, which will check when a .c file is opened for a .vim.custom in the same directory as the .c file.
au BufNewFile,BufRead *.c call CheckForCustomConfiguration()
function! CheckForCustomConfiguration()
" Check for .vim.custom in the directory containing the newly opened file
let custom_config_file = expand('%:p:h') . '/.vim.custom'
if filereadable(custom_config_file)
exe 'source' custom_config_file
endif
endfunction
You can also put autocommands in your .vimrc which set specific options on a per-path basis.
au BufRead,BufNewFile /path/to/project1/* setl sw=4 et
au BufRead,BufNewFile /path/to/project2/* setl sw=3 noet
Plugin doing the right thing:
http://www.vim.org/scripts/script.php?script_id=441
“This plugin searches for local vimrc files in the filesystem tree of the currently opened file. By default it searches for all ".lvimrc" files from the file's directory up to the root directory and loads them in reverse order. The filename and amount of loaded files is customizable through global variables.”
Assuming your fellow developers won't complain about it, you can always add vim settings to each file in the comments.
/*
* vim:ts=4:sw=4:expandtab:...
*/
int main(int argc, char **argv)
{
...
I created an open-sourced tool for just this purpose. Forget the headers, scanning, configurations, and local vimrc files.
Try swim.
Swim
swim is a quick tool for switching vimrc files and creating convenient aliases. Here's a short usage list. See the Github repo for a walkthrough gif and download instructions:
Usage
swim add ~/dotfiles/myVimrc favorite #Add new swim alias
swim ls #Show available swim aliases
swim add https://raw.githubusercontent.com/dawsonbotsford/swim/master/exampleVimrcs/vimrcWikia.vim example
swim with favorite #Set alias favorite as primary .vimrc
swim with main #Set alias main as primary .vimrc
Read More
https://github.com/dawsonbotsford/swim
After trying out the localvimrc plugin suggested by the previous poster, I very much like having non-futzy per-project control over vim settings.
It does ask confirmation before loading a .lvimrc file by default but there is a setting to automatically load .lvimrc files. Some might see this as a security hole, but it works as advertised.
I chose to .gitignore the .lvimrc files. Alternatively you can check them in as a form of shared settings (tab/space expansion, tabstops, other project-specific settings).
As mentioned by sledge the usage of that plug-in is the best option I have seen and use. jerseyboy commented that the utility recommended ask for confirmation before loading (ie. after opening every file). To avoid this just set at your main .vimrc the list of local .lvimrc files:
let g:localvimrc_whitelist='/development/kernel/.lvimrc'
Here's a variation on jamessan's
function! ConditionalLoad()
let cwd = getcwd()
if getcwd() =~ $HOME . "/src/mobile"
so $HOME/.vim.mobile
endif
endfunction
autocmd VimEnter * call ConditionalLoad()
I will frequently launch vi without a specific file that I'm jumping to so this enables loading config conditionally based on the current working directory. Downside is that the config isn't applied based on file but off of working directory.
I work in several groups, each of which has its own tab/indentation/spacing standards in C.
I work with all sorts of open source, all at the same time. It's not practical to be creating separate .vimrc files and reconfiguring the formatting standards. More than a decade ago, I finally got tired of dealing with the editor configuration and wrote a program called autotab to handle it.
When autotab is set up with Vim suggested, each time you load a file into Vim, autotab is invoked on it, and the Vim settings output autotab are passed to a :set command.
autotab reads several thousand lines from the file, analyzes them and determines the settings for the expandtab, tabstop and shiftwidth parameters.
It figures out whether the file uses hard tabs or just spaces for indentation, and it figures out the indentation size. If the file is indented with tabs, it figures out the right tab size, based on rendering the file sample using various tab sizes and judging it according to heuristics like line-over-line alignment of internal elements.
It works well enough that I stopped tweaking the algorithm years ago. If it gets confused, it's almost always because the file has formatting issues, such as the use of multiple conventions at the same time.
It is also "agnostic" of the file type and works well with a variety of different languages. I use it not only over C, but shell scripts, Lisp, Makefiles, HTML, and what have you.
Note that it doesn't handle other parameters of formatting that may be project-specific, like for instance, in C files, whether case labels in a switch statement are indented or not, or whether wrapped function argument lists are simply indented, or aligned to the opening parenthesis of the argument list. Vim does have settings for that sort of thing, and so the program could be plausibly extended to analyze the style and output those parameters.
Looking for mostly the same issue I also found the Sauce plug-in: http://www.vim.org/scripts/script.php?script_id=3992
It claims:
Sauce is a lightweight manager for multiple vimrc files, which can be used to load different settings for different environments. In short, you can maintain lots of different vim settings files and only load the one(s) you need when you need them.
I find it particularly interesting that it keeps it configuration all in its data directory instead of expecting the user to sprinkle dotfiles across the filesystem. This though often rather a metter of personal taste.
I have yet to test it though.
You can use stow for switching configuration (any dotfiles, not only .vimrc)
Install stow:
$ apt install stow
Create multiple directories for each configurations:
~$ ls -d ~/dotfiles/vim*
vim-all vim-webdev vim-go
Put different .vimrc's in them:
$ find ~/dotfiles -name .vimrc
/home/username/vim-golang/.vimrc
/home/username/vim-webdev/.vimrc
/home/username/vim-all/.vimrc
Now you can instantinate vim-golang config with this command (should be run inside dotfiles directory):
~$ cd ~/dotfiles
dotfiles$ stow -v vim-golang
LINK: .vimrc => dotfiles/vim-golang/.vimrc
Now it's linked:
$ cd ~ && ls -l .vimrc
.vimrc -> dotfiles/vim-golang/.vimrc
If you need to switch config, just re-stow it:
~$ cd dotfiles
dotfiles$ stow -v -D vim-golang
UNLINK: .vimrc
dotfiles$ stow -v vim-webdev
LINK: .vimrc => dotfiles/vim-webdev/.vimrc
$ cd ~ && ls -l .vimrc
.vimrc -> dotfiles/vim-webdev/.vimrc
More reading of it here: Managing dotfiles with GNU stow
Pros: pretty simple, no vim plugin dependencies, can be used for managing all dotfiles, not only .vimrc.
Cons: configs are independent of each other, you need to manage/update each of them separately (if you dont switch/update you configs too often - it'll not be the issue).

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