[Openmcl-devel] Running ccl as a shebang script

[Ron Garret]

Running ccl as a shebang script is not a supported feature.  It turns out that it’s possible to do it, but it requires some horrible hackery: you have to define a reader macro that treats #! as a comment delimiter, and you have to put that in your ccl-init file.  That seemed too ugly to me, so I wrote a little C program that reads past the first line of the script and pipes the rest into ccl’s stdin.  That seemed like a cleaner solution.  Just in case anyone else cared about this I thought I’d share the code:


➔ cat cclsh.c
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>

char *args[] = {"cclsh", "-Q", "-b"};

int main(int argc, char *argv[], char *envp[]) {
  if (argc!=3) {
    fprintf(stderr, "Usage: %s [path-to-ccl-executable] [path-to-script]",
	    argv[0]);
    exit(-1);
  }
  int fd = open(argv[argc-1], O_RDONLY);
  char c = ' ';
  while (c!='\n') read(fd, &c, 1);
  fclose(stdin);
  dup(fd);
  close(fd);
  execve(argv[1], args, envp);
}


Example:

➔ cat test
#!cclsh /Users/ron/devel/ccl/active/dx86cl64
(list 1 2 3)
➔ ./test
(1 2 3)

rg