Check vim version and python support from a bash script - bash

Question

I have a bash script that is dependent on vim being at least version 7.4 and is installed with python. I need to check if the above condition matches, if not exit and ask user to update their vim.
So far all I can think of is something like below
has_vim = command -v vim >/dev/null
if ! $has_vim; then
echo "must have vim installed."
exit 1
fi
// Here I want do as the following pseudo code
vim_info = $(vim --version | grep python)
// suggest me if there is another way
vim_version = // find version info from $vim_info
has_python_support = // find python support from $vim_info
if ! $vim_version >= 7.4 && ! has_python_support; then
echo "vim version must be at least 7.4 and must be installed with python support"
fi
// everything is ok. carry on
At the moment all I can think of is checking $vim_info for expected vim version and python support.
To boil down the question into meaningful sentence:
How do I check if vim version is greater or equal to 7.4 and has python support from bash script?

Answer 1

When I ask my vim for vim --version, it spits out something like this:
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Sep 16 2015 08:44:57)
Included patches: 1-872
Compiled by <alexpux#gmail.com>
Huge version without GUI. Features included (+) or not (-):
+acl +farsi +mouse_netterm +syntax
+arabic +file_in_path +mouse_sgr +tag_binary
+autocmd +find_in_path -mouse_sysmouse +tag_old_static
-balloon_eval +float +mouse_urxvt -tag_any_white
-browse +folding +mouse_xterm -tcl
++builtin_terms -footer +multi_byte +terminfo
+byte_offset +fork() +multi_lang +termresponse
+cindent +gettext -mzscheme +textobjects
-clientserver -hangul_input +netbeans_intg +title
+clipboard +iconv +path_extra -toolbar
+cmdline_compl +insert_expand +perl/dyn +user_commands
+cmdline_hist +jumplist +persistent_undo +vertsplit
+cmdline_info +keymap +postscript +virtualedit
+comments +langmap +printer +visual
+conceal +libcall +profile +visualextra
+cryptv +linebreak +python/dyn +viminfo
+cscope +lispindent +python3/dyn +vreplace
+cursorbind +listcmds +quickfix +wildignore
+cursorshape +localmap +reltime +wildmenu
+dialog_con -lua +rightleft +windows
+diff +menu +ruby/dyn +writebackup
+digraphs +mksession +scrollbind -X11
-dnd +modify_fname +signs -xfontset
-ebcdic +mouse +smartindent -xim
+emacs_tags -mouseshape -sniff -xsmp
+eval +mouse_dec +startuptime -xterm_clipboard
+ex_extra -mouse_gpm +statusline -xterm_save
+extra_search -mouse_jsbterm -sun_workshop -xpm
So, parsing the output would be a good bet here.
Find the version number and store it in VIMVERSION:
VIMVERSION=$(vim --version | head -1 | cut -d ' ' -f 5)
From here, check In bash shell script how do I convert a string to an number for how to compare the string result against your minimum needed 7.4.
Check for Python support (HAS_PYTHON will be 0 if Python is not available):
HAS_PYTHON=$(vim --version | grep -c '+python')
Check explicitly for Python 3 (again, HAS_PYTHON3 will be 0 if Python 3 is not available):
HAS_PYTHON3=$(vim --version | grep -c '+python3')
This might be a bit rough but I think you get the idea.

Answer 2

#!/bin/bash
has_vim=$(command -v vim >/dev/null)
if ! $has_vim; then
echo "must have vim installed."
exit 1
fi
# Checking the python support based on the line output received
has_python_support=$(vim --version | grep -c python)
# Matching the decimal pattern from the first line
vim_version=$(vim --version | head -1 | grep -o '[0-9]\.[0-9]')
if [ ! $(echo "$vim_version >= 7.4" | bc -l) ] && [ ! $has_python_support ]; then
echo "vim version must be at least 7.4 and must be installed with python support"
else
echo "vim version is > 7.4"
fi
Should solve your problem

Answer 3

If you have a running Vim instance already, or if you can create one, you can always just ask Vim itself:
$ vim --servername SOME_NAME --remote-expr "has('python')"
1
$ vim --servername SOME_NAME --remote-expr "v:version"
704
But if Vim isn't already running it's probably more straightforward to parse the --version output as suggested in other answers.