I'm trying to set up Vim to detect when a .tex file contains the command '\usepackage{sagemath}', and run a command accordingly. I've gotten to
:au BufReadPost,BufWritePost *.tex TTarget sagepdf
but that will fire for all .tex files, which isn't what I want.
Theres an example in my filetype.vim on how to destinguish html types. You can easily modify to suit your logic. Note the getline(n) =~ lines
" HTML (.shtml and .stm for server side)
au BufNewFile,BufRead *.html,*.htm,*.shtml,*.stm call s:FThtml()
" Distinguish between HTML, XHTML and Django
fun! s:FThtml()
let n = 1
while n < 10 && n < line("$")
if getline(n) =~ '\<DTD\s\+XHTML\s'
setf xhtml
return
endif
if getline(n) =~ '{%\s*\(extends\|block\)\>'
setf html.django_template
" setf htmldjango
return
endif
let n = n + 1
endwhile
setf html
endfun