From f3fac5ff9a9532964f7cf2b36567af2ac579bed8 Mon Sep 17 00:00:00 2001
From: Wu Zhenyu <wuzy01@qq.com>
Date: Tue, 18 Oct 2022 22:22:58 +0800
Subject: [PATCH] Support shebang detection

---
 autoload/requirements/scripts.vim | 28 ++++++++++++++++++++++++++++
 ftdetect/requirements.vim         |  1 +
 2 files changed, 29 insertions(+)
 create mode 100644 autoload/requirements/scripts.vim

diff --git a/autoload/requirements/scripts.vim b/autoload/requirements/scripts.vim
new file mode 100644
index 0000000..9a90038
--- /dev/null
+++ b/autoload/requirements/scripts.vim
@@ -0,0 +1,28 @@
+""
+" Refer $VIMRUNTIME/autoload/dist/script.vim in vim
+" or $VIMRUNTIME/scripts.vim in neovim. When a file's shebang is like
+" "pip install -r" or "pip-compile", set its filetype to |requirements|.
+function! requirements#scripts#shabang() abort
+    let s:line1 = getline(1)
+
+    if s:line1 =~# "^#!"
+        if s:line1 =~# '^#!\s*\S*\<env\s'
+            let s:line1 = substitute(s:line1, '\S\+=\S\+', '', 'g')
+            let s:line1 = substitute(s:line1, '\(-[iS]\|--ignore-environment\|--split-string\)', '', '')
+            let s:line1 = substitute(s:line1, '\<env\s\+', '', '')
+        endif
+        if s:line1 =~# '^#!\s*\a:[/\\]'
+            let s:name = substitute(s:line1, '^#!.*[/\\]\(\i\+\).*', '\1', '')
+        elseif s:line1 =~# '^#!.*\<env\>'
+            let s:name = substitute(s:line1, '^#!.*\<env\>\s\+\(\i\+\).*', '\1', '')
+        elseif s:line1 =~# '^#!\s*[^/\\ ]*\>\([^/\\]\|$\)'
+            let s:name = substitute(s:line1, '^#!\s*\([^/\\ ]*\>\).*', '\1', '')
+        else
+            let s:name = substitute(s:line1, '^#!\s*\S*[/\\]\(\i\+\).*', '\1', '')
+        endif
+        if s:name =~# '^pip'
+            set ft=requirements
+        endif
+    endif
+endfunction
+" vim: et sw=4 ts=4 sts=4:
diff --git a/ftdetect/requirements.vim b/ftdetect/requirements.vim
index 71468e2..da03472 100644
--- a/ftdetect/requirements.vim
+++ b/ftdetect/requirements.vim
@@ -59,6 +59,7 @@ augroup requirements
     autocmd!
     au BufNewFile,BufRead *.{txt,in} if s:isRequirementsFile() | set ft=requirements | endif
     au BufNewFile,BufRead *.pip set ft=requirements
+    au BufNewFile,BufRead * if !did_filetype() | call requirements#scripts#shabang() | endif
 augroup END
 
 " vim: et sw=4 ts=4 sts=4: