Vim and Compatibility

Trends for Development Style

Updating vs. Keeping

Also Vim has same trends.

Example: End of Life for cybozu Live

• Groupware web service "cybozu Live" by Cybozu, Inc in Japan.
• Start from 2009-11-26.
• 2 million users.
• Discontinuing was announced on 2017-10-24.
• End of support on 2019-04-15.

• Cybozu have used Java Seasar projects in past.
• Many Seasar projects are End of Life (EOL) now.
• This announcement is due to Seasar EOL probably.

• Ref: サイボウズLive - 西尾泰和のScrapbox - Scrapbox
• Ref: サイボウズLiveサービス終了のお知らせ | 無料グループウェア サイボウズLive

How do we keep our development?

Methodology for Keeping

POSIXism (POISX fundamentalism)
POSIX原理主義

Write Once,
Work Anytime/Anywhere

POSIX and POSIXism

Good/Bad Point of POSIXism

3 Guidelines for POSIXism

• Essence of POSIXism is to keep portability.
• We can use de jure standard (IEEE, ISO, ECMA, JIS) or official reference.

Application for POSIXism

Shell script with conforming to POSIX	Web app with conforming to W3C
Parsrs https://github.com/ShellShoccar-jpn/Parsrs	Metropiper http://lab-sakura.richlab.org/METROPIPER/HTML/MAIN.HTML
ShellShoccar-jpn/Parsrs: CSV, JSON, XML text parsers and generators written in pure POSIX shellscript	"Metropiper" for train aproaching information web app.(接近情報表示プログラム「メトロパイパー」)
General parser and generator for JSON, XML. Good bye, jq, jo, xmllint	Showing Tokyo metro train position info. Developed using parsrs.

Publication

Paper	HP
Peer reviewed paper on Information Processing Society of Japan 2017-10-15 https://www.ipsj.or.jp/dp/contents/publication/32/S0804-R1601.html	posixism.org http://posixism.org/

• POSIXism is published some media.
• Paper and HP.

Example for Applying POSIXism to Our Life

• Twitter is popular in Japan. But Twitter is only one, not portable.
• If Twitter bans your account, it is the end.
• Try GNU Social or Mastodon instead.

Write .vimrc Once,
Work Vim Anytime/Anywhere

Vim Overview

Vim Inheritance

ed

↓

ex

↓

vi

↓

vim

Developers

Initial release	Name	Creator (Nick name)	Portrait	Bio
1969-08	ed	Kenneth Lane Thompson (Ken Thompson)	(Wikimedia Commons)	Born 1943-02-04 American Computer scientist UNIX developer UTF-8 encoding developer Go language co-designer.
1976-09 1979-05	ex vi	William Nelson Joy (Bill Joy)	(Wikimedia Commons)	Born 1954-11-08 American Computer scientist csh developer Co-founder of Sun Microsystems
1988	vim	Bram Moolenaar	(Wikimedia Commons) (http://www.zimbu.org/)	Born 1961 Germans Programmer Developer for Zimbu language.

Vi History

Vi = Visual Interface or Visual Editor

• Vi is super set of ex.
• After vi 3.7, many vi clones were born.
• vi and vi clone are available for UNIX like OS.

vi - Wikipedia

Vim History

Ref: Talk of TAKATA@VimConf 2016 Introduction to Vim 8.0

Real VPS Specification

CentOS 5 looks like the oldest supported OS.

OS Default Vim Version

• Mac OS X 10.6 is last version for DISK distribution.
• Commercial UNIX is the longest End of Life (15-25 years).
• CentOS 5.0&5.11 has the oldest default Vim 7.0.
• We can assume the oldest default vim version is Vim 7.0 (next 7.3 probably).

Standard Vim function

Interface

Interface is important for extension Vim function.

• perl and python2 is supported since old Vim 5.0.
• Lua and Python3 is supported recently in Vim history.

Standard Plugin

:help standard-pugin-list or $VIMRUNTIME/plugin/README.txt

• Almost standard plugin bundled on Vim 6.0 and 7.0.
• Standard plugins is enabled by default.

Ref: Talk of Linda_pp@VimConf2013, Do You Know about Vim Runtime Files? // Speaker Dec

Macro

$VIMRUNTIME/macros/README.txt

Since Vim 8.0, dvorak, editexisting, justify, matchit, shellmenu, swapmouse is moved $VIMRUTNIME/pack.

Macro is existing since old Vim release.

Macros is not enabled on default. If you want to use macro, try like following commands.

:source $VIMRUNTIME/<macro-name>.vim

:runtime macros/<macro-name>vim

Ref: talk of Linda_pp@VimConf2013, Do You Know about Vim Runtime Files? // Speaker Dec

Bundled Commands: Alias

:help starting

ex, gvim, vimdiff is useful alias especially.

Bundled Commands: External Commands

Official Vim archive for Windows (gvim*.exe) is here: ftp://ftp.vim.org/pub/vim/pc/

Windows Vim is installed C:\Program Files (x86)\Vim\. External commands have .exe extension.

Find external commands by following cmd.exe commands.

dir /s /b "%ProgramFiles(x86)%\Vim\*.exe"

• ctags have not been bundled since Vim 6.0.
• tee.exe is bundled on Vim 8.0.
• xxd.exe and diff.exe is available for default Vim.

My past research : My Future Sight for Past: Windows版Vimインストール時の付属コマンド

Tips for Compatible Vim

Concept for Compatible Vim

• Vim has many function for compatibility.
• Before using new function, check them.
• Or setting option appropriately.

if <is-enabled-new-feature>
	<use-new-feature-here>
endif
set <general-option>=<env1>,<env2>,<env3>

Version

if has('cscope')
  set cscopequickfix=s-,g-,d-,c-,t-,e-,f-,i-
  if v:version >= 800 || has('patch-7.4.1952')
    let &cscopequickfix .= ',a-'
  endif
endif

Feature: has()

has() is available for checking if interface, OS, GUI, compiled feature enabled

(:help featurelist).

If you want to know detail about OS, use external commands by system().

Example of has()

""" Platform
let s:IS_WINDOWS   = has('win64') || has('win32')   || has('win16')
let s:IS_CYGWIN    = has('win32unix')
let s:IS_MAC       = has('mac')   || has('macunix') || has('gui_macvim')
let s:IS_LINUX     = has('unix')  && !s:IS_MAC      && !s:IS_CYGWIN
let s:IS_WINDOWS_7 = s:IS_WINDOWS && system('VER') =~# 'Version 6.1'

"" mouse
if has('mouse')
  set mouse=a
  set ttymouse=xterm2
endif

Definition: exists()

exists() is available for checking if variable, option, function, event enabled.

+option-name, *funcname, :cmdname, ##event is often used.

Example of exists()

In .vimrc, exists('+option-name') is enough for option compatibility.

New option needs to check by exists().

if exists('+packpath')
	set packpath+=~/.vim
endif

if exists('##CmdlineEnter')
	autocmd CmdlineEnter * pwd
endif

Release v8.0.1206: patch 8.0.1206: no autocmd for entering or leaving the command line · vim/vim

File Access

If we want to use external exe or file, check it enabled.

executable, filereadable, shellescape, system is often used.

Example of File Access

## For :grep
if executable('ag')
  set grepprg=ag\ --vimgrep\ $*
  set grepformat=%f:%l:%c:%m
endif

"" Add executable permission for shebang files
autocmd BufWritePost * :call s:Add_execmod()
function! s:Add_execmod()
  let s:line = getline(1)
  if strpart(s:line, 0, 2) == '#!'
    let s:IS_WINDOWS   = has('win64') || has('win32')   || has('win16')
    if s:IS_WINDOWS
      call system('icacls '    . shellescape(expand('%') . ' /grant ' . $USERNAME . ':(X)'))
    else
      call system('chmod +x -- ' . shellescape(expand('%')))
    endif
  endif
endfunction

Vim Configuration for Encodings

help: mbyte-encoding

Example for Basic Concept

Typical Character Set

Typical Encoding

• Windows-31J (CP932) is almost super set for Shift_JIS.
• In software, use CP932 instead of Shift_JIS.

BOM (Byte Order Mark)

Multi byte encoding is depends on architecture (Big-endian, Little-endian).

UTF-16 and UTF-32 is encoding a character from multi bytes.

For detecting endian, append mark (BOM) to start of the file.

No BOM means Big-endian.

UTF-8 is not depends on order of byte. UTF-8 BOM is only mark for easy detecting  (no meaning order).

In Vim, set bomb and set nobomb are available for appending/removing BOM only Unicode encoding.

Vim Specific Encoding

Vim supports many encoding. You can check :help encoding-names or iconv -l.

Following value is vim specific encoding names.

Can You Open These Files Correctly?

encoding-test.zip

(https://senooken.jp/public/20171104/encoding-test.zip)

encoing-test.zip is including following encoding and content.

あｱ

あｱ

あｱ

あｱ

あ

あｱ①

If your .vimrc is compatible, you can open these files correctly.

(We can check following command for fileencodings test without .vimrc.)

" vim -u NONE --cmd "set fencs=<encs>" file.txt
vim -u NONE --cmd "set fencs=utf-8" cp932.txt

fileencodings for Japanese

• fileencodings is list for fileencoding (text file encoding).
• Checking is starting from first fileencodings item until success.
• Some encodings misunderstand other encoding. And some encoding is share of subset (ex. ASCII).
• Order of fileencodings is important.

"" Example of fileencodings for all clear encoding-test.zip
set fileencodings=ucs-bom,iso-2022-jp,utf-8,euc-jp,cp932

This setting is not perfect. If we try opening UTF-16 without BOM, encoding is failed. But almost good.

"" Fix 'fileencoding' to use 'encoding' if the buffer only ASCII characters.
autocmd BufReadPost *
  \   if &modifiable && !search('[^\x00-\x7F]', 'cnw')
  \ |   setlocal fileencoding=utf-8
  \ | endif

fileformats

• fileformat gives the <EOL> (end-of-line, line break).
  • dos: <CR> <NL>
  • unix: <NL>
  • mac: <CR>
• fileformats is list for fileformat.
• All list items of fileformats is checked automatically.
• Order of fileformats is not so important as fileencodings.
• First item is used for empty file (or all item mismatched file).

set fileformats=unix,dos,mac

End of Line (EOL)

Vim has been forcing to append line break to end of file in writing text file for a long time.

For keeping default EOL, add nofixendofline option to .vimrc in Vim 8.0 (vim 7.4.785)

最後に改行がないファイルが作れない · Issue #152 · vim-jp/issues

"" Disabled to append LF automatically in writing
if exists('+fixendofline')
	autocmd BufWritePre * setlocal nofixendofline
endif

Then, set endofline and set noendofline is appending/removing EOL.

ambiwidth

• In east Asia, assign 1 byte character to half width, 2 bytes character to full width in practice.
• ambiwidth option operate these appearance.
• Default is 'single'. For Japanese, 'double' is recommended.

set ambiwidth=double

statusline

It is useful for text file information on statusline.

Example

"" Statusline
set laststatus=2
set statusline =[%n]%<%f    " File name
set statusline+=\ %m%r%h%w  " Flag for modified, readonly, help buffer, preview
set statusline+=%<%y        " filetype
set statusline+=%{'['.(&fenc!=''?&fenc:&enc).':'.&ff.']'}  " Encoding
set statusline+=%{&bomb?'[bomb]':''}   " BOM
set statusline+=%{&eol?'':'[noeol]'}   " EOL
set statusline+=[%04B]                 " Character code
set statusline+=%=\ %4l/%4L\|%3v\|%4P  " Current position

Summary

• Updating vs. Keeping
• Methodology for keeping: POSIXism
• Vim overview
  • hisotry
  • default version
  • bundled files
• Tips for compatibility
  • version, exists(), has()
  • File access
  • Encoding

Write Once,
Work Anytime/Anywhere
posixism.org