#!/bin/sh

# TODO: handle "#!/usr/bin/env foo" somehow

while read filename; do

    # common cases 

    sed -n -e '1s:^#![[:space:]]*\(/[^[:space:]]\{1,\}\).*:\1:p' "$filename"

    #!/usr/bin/env /foo/bar

    sed -n -e '1s:^#![[:space:]]*[^[:space:]]*/bin/env[[:space:]]\{1,\}\(/[^[:space:]]\{1,\}\):\1:p' "$filename"

done