One-line header enabling executable single-file C scripts (via @reddit)

hello.c

//&>/dev/null;x="${0%.*}";[ ! "$x" -ot "$0" ]||(rm -f "$x";cc -o "$x" "$0")&&"$x" $*;exit

// Usage: bash ./hello.c

#include <stdio.h>

int main(int argc, char *argv[])
{
        printf("Hello world!\n");
        return 0;
}