#!/usr/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