How can I make a TeX file executable?

Question

Under UNIX, to my knowledge, any regular file can be made executable with the addition of a shebang:

#! /path/to/executing-program --with --options

How can I apply the same principle to a TeX file without altering syntax rules for the entire document?

$ cat > tmp.tex
#! /usr/bin/env tex --mystery --options
hello, world
\bye
$ chmod +x tmp.tex
$ ./tmp.tex
$ dvi2tty -q tmp.dvi | grep .
hello, world
                                   1
$ logout

Answer 1

This is file seanenv.tex:

#! /usr/bin/env pdflatex \catcode35=14 \input
\catcode`\#=6
\documentclass{article}
\begin{document}
Hello, Sean!
\end{document}

After chmod u+x seanenv.tex, I can issue

./seanenv.tex

and the seanenv.pdf file is compiled.

Note that 35 is the character code of #, which must be made into a comment character before TeX rereads the file. After this, # is given back its category code 6.

This is not limited to pdflatex; the same strategy will work with tex and so on.

Answer 2

It hangs for me as well. Changing the first line to use the path to pdflatex (instead of going via /usr/bin/env) fixes it for me:

#! /bin/pdflatex \catcode35=14 \input

Change /bin/pdflatex if needed to the full path for pdflatex. The command:

which pdflatex

will tell you what this is.