Read LaTeX source from standard input, render to PNG and move to clipboard. Paste nice equations anywhere.

tex2clip.sh

#!/usr/bin/env bash
tmpdir="$(mktemp -d)"
texfile="$tmpdir/tmp.tex"

echo "\documentclass[varwidth]{standalone}
\usepackage{amsmath,amsfonts,amssymb,amsthm}
\usepackage{color}
\usepackage[utf8]{inputenc}
\begin{document}
" > "$texfile"

cat >> "$texfile"
echo "\end{document}" >> "$texfile"

pdflatex -output-directory "$tmpdir" tmp.tex
pdftocairo -r 600 -png -transp -singlefile "$tmpdir/tmp.pdf" "$tmpdir/tmp"
xclip -selection clipboard -t image/png -i "$tmpdir/tmp.png"

rm -r "$tmpdir"