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diff --git a/runtime/doc/usr_43.txt b/runtime/doc/usr_43.txt new file mode 100644 index 0000000..11647f6 --- /dev/null +++ b/runtime/doc/usr_43.txt @@ -0,0 +1,179 @@ +*usr_43.txt* For Vim version 8.1. Last change: 2015 Oct 23 + + VIM USER MANUAL - by Bram Moolenaar + + Using filetypes + + +When you are editing a file of a certain type, for example a C program or a +shell script, you often use the same option settings and mappings. You +quickly get tired of manually setting these each time. This chapter explains +how to do it automatically. + +|43.1| Plugins for a filetype +|43.2| Adding a filetype + + Next chapter: |usr_44.txt| Your own syntax highlighted + Previous chapter: |usr_42.txt| Add new menus +Table of contents: |usr_toc.txt| + +============================================================================== +*43.1* Plugins for a filetype *filetype-plugin* + +How to start using filetype plugins has already been discussed here: +|add-filetype-plugin|. But you probably are not satisfied with the default +settings, because they have been kept minimal. Suppose that for C files you +want to set the 'softtabstop' option to 4 and define a mapping to insert a +three-line comment. You do this with only two steps: + + *your-runtime-dir* +1. Create your own runtime directory. On Unix this usually is "~/.vim". In + this directory create the "ftplugin" directory: > + + mkdir ~/.vim + mkdir ~/.vim/ftplugin +< + When you are not on Unix, check the value of the 'runtimepath' option to + see where Vim will look for the "ftplugin" directory: > + + set runtimepath + +< You would normally use the first directory name (before the first comma). + You might want to prepend a directory name to the 'runtimepath' option in + your |vimrc| file if you don't like the default value. + +2. Create the file "~/.vim/ftplugin/c.vim", with the contents: > + + setlocal softtabstop=4 + noremap <buffer> <LocalLeader>c o/**************<CR><CR>/<Esc> + let b:undo_ftplugin = "setl softtabstop< | unmap <buffer> <LocalLeader>c" + +Try editing a C file. You should notice that the 'softtabstop' option is set +to 4. But when you edit another file it's reset to the default zero. That is +because the ":setlocal" command was used. This sets the 'softtabstop' option +only locally to the buffer. As soon as you edit another buffer, it will be +set to the value set for that buffer. For a new buffer it will get the +default value or the value from the last ":set" command. + +Likewise, the mapping for "\c" will disappear when editing another buffer. +The ":map <buffer>" command creates a mapping that is local to the current +buffer. This works with any mapping command: ":map!", ":vmap", etc. The +|<LocalLeader>| in the mapping is replaced with the value of the +"maplocalleader" variable. + +The line to set b:undo_ftplugin is for when the filetype is set to another +value. In that case you will want to undo your preferences. The +b:undo_ftplugin variable is executed as a command. Watch out for characters +with a special meaning inside a string, such as a backslash. + +You can find examples for filetype plugins in this directory: > + + $VIMRUNTIME/ftplugin/ + +More details about writing a filetype plugin can be found here: +|write-plugin|. + +============================================================================== +*43.2* Adding a filetype + +If you are using a type of file that is not recognized by Vim, this is how to +get it recognized. You need a runtime directory of your own. See +|your-runtime-dir| above. + +Create a file "filetype.vim" which contains an autocommand for your filetype. +(Autocommands were explained in section |40.3|.) Example: > + + augroup filetypedetect + au BufNewFile,BufRead *.xyz setf xyz + augroup END + +This will recognize all files that end in ".xyz" as the "xyz" filetype. The +":augroup" commands put this autocommand in the "filetypedetect" group. This +allows removing all autocommands for filetype detection when doing ":filetype +off". The "setf" command will set the 'filetype' option to its argument, +unless it was set already. This will make sure that 'filetype' isn't set +twice. + +You can use many different patterns to match the name of your file. Directory +names can also be included. See |autocmd-patterns|. For example, the files +under "/usr/share/scripts/" are all "ruby" files, but don't have the expected +file name extension. Adding this to the example above: > + + augroup filetypedetect + au BufNewFile,BufRead *.xyz setf xyz + au BufNewFile,BufRead /usr/share/scripts/* setf ruby + augroup END + +However, if you now edit a file /usr/share/scripts/README.txt, this is not a +ruby file. The danger of a pattern ending in "*" is that it quickly matches +too many files. To avoid trouble with this, put the filetype.vim file in +another directory, one that is at the end of 'runtimepath'. For Unix for +example, you could use "~/.vim/after/filetype.vim". + You now put the detection of text files in ~/.vim/filetype.vim: > + + augroup filetypedetect + au BufNewFile,BufRead *.txt setf text + augroup END + +That file is found in 'runtimepath' first. Then use this in +~/.vim/after/filetype.vim, which is found last: > + + augroup filetypedetect + au BufNewFile,BufRead /usr/share/scripts/* setf ruby + augroup END + +What will happen now is that Vim searches for "filetype.vim" files in each +directory in 'runtimepath'. First ~/.vim/filetype.vim is found. The +autocommand to catch *.txt files is defined there. Then Vim finds the +filetype.vim file in $VIMRUNTIME, which is halfway 'runtimepath'. Finally +~/.vim/after/filetype.vim is found and the autocommand for detecting ruby +files in /usr/share/scripts is added. + When you now edit /usr/share/scripts/README.txt, the autocommands are +checked in the order in which they were defined. The *.txt pattern matches, +thus "setf text" is executed to set the filetype to "text". The pattern for +ruby matches too, and the "setf ruby" is executed. But since 'filetype' was +already set to "text", nothing happens here. + When you edit the file /usr/share/scripts/foobar the same autocommands are +checked. Only the one for ruby matches and "setf ruby" sets 'filetype' to +ruby. + + +RECOGNIZING BY CONTENTS + +If your file cannot be recognized by its file name, you might be able to +recognize it by its contents. For example, many script files start with a +line like: + + #!/bin/xyz ~ + +To recognize this script create a file "scripts.vim" in your runtime directory +(same place where filetype.vim goes). It might look like this: > + + if did_filetype() + finish + endif + if getline(1) =~ '^#!.*[/\\]xyz\>' + setf xyz + endif + +The first check with did_filetype() is to avoid that you will check the +contents of files for which the filetype was already detected by the file +name. That avoids wasting time on checking the file when the "setf" command +won't do anything. + The scripts.vim file is sourced by an autocommand in the default +filetype.vim file. Therefore, the order of checks is: + + 1. filetype.vim files before $VIMRUNTIME in 'runtimepath' + 2. first part of $VIMRUNTIME/filetype.vim + 3. all scripts.vim files in 'runtimepath' + 4. remainder of $VIMRUNTIME/filetype.vim + 5. filetype.vim files after $VIMRUNTIME in 'runtimepath' + +If this is not sufficient for you, add an autocommand that matches all files +and sources a script or executes a function to check the contents of the file. + +============================================================================== + +Next chapter: |usr_44.txt| Your own syntax highlighted + +Copyright: see |manual-copyright| vim:tw=78:ts=8:noet:ft=help:norl: |