How to set on executable bit for a particular file automatically

Question

I want that when i make create a particular file, suppose i create it in vim editor, the created file should get executable permission as well when it gets created . I want this as i am creating some python files and don't want to explicitly set permissions for the file so i want some way so that executable bit is set as soon i create a file with particular extension or with a particular editor.

Answer 1

For vim, you have powerful scripting available. For example, in my .vimrc, I have:

" Stolen from http://www.debian-administration.org/articles/571
" Sets +x on stuff starting with the magic shebang.
au BufWritePost * if getline(1) =~ "^#!" | silent !chmod a+x <afile>

If you want to do it by filename only, instead of looking for the #! line, you could do:

au BufWritePost *.ext silent !chmod a+x <afile>     " untested

That article on Debian Administration has instructions for EMACS as well.

Answer 2

As much as I like derobert's answer, it causes VIM to give me the following warning:

W16: Warning: Mode of file "test.sh" has changed since editing started

The following (somewhat longer) code solves that problem (requires a Python-enabled vim):

function! SetExecutableBit()
python <<EOD
import vim
import os
import stat
filename = vim.current.buffer.name
mode = os.stat(filename).st_mode
os.chmod(filename, mode | stat.S_IXUSR)
EOD
endfunction

autocmd BufWritePost *
    \ if getline(1) =~ "^#!" | call SetExecutableBit()

Answer 3

put

umask 0544

in your ~/.bashrc

When you run without arg, you'll see:

0022

Suggestion of UNIX is 0022.But your case is ...