/*
 * As its sole author, I explicitly place this program in the public domain.
 * It may be used by anyone in any way for any purpose, though I would
 * appreciate credit where it's due.
 *		der Mouse, mouse@rodents.montreal.qc.ca, 1998-08-05
 */

#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <strings.h>

extern const char *__progname;

static int fd;
static int have_fd = 0;
static int op = 0;
static int vflag = 0;

static void handleargs(int ac, char **av)
{
 int skip;
 int errs;
 char *ep;

 skip = 0;
 errs = 0;
 for (ac--,av++;ac;ac--,av++)
  { if (skip > 0)
     { skip --;
       continue;
     }
    if (**av != '-')
     { if (! have_fd)
	{ fd = strtol(*av,&ep,0);
	  if ((fd < 0) || *ep || (ep == *av))
	   { fprintf(stderr,"%s: invalid file descriptor argument `%s'\n",__progname,*av);
	     errs ++;
	   }
	  else
	   { have_fd = 1;
	   }
	}
       else
	{ fprintf(stderr,"%s: extra argument `%s'\n",__progname,*av);
	  errs ++;
	}
       continue;
     }
    if (!strcmp(*av,"-sh"))
     { op |= LOCK_SH;
       continue;
     }
    if (!strcmp(*av,"-ex"))
     { op |= LOCK_EX;
       continue;
     }
    if (!strcmp(*av,"-nb"))
     { op |= LOCK_NB;
       continue;
     }
    if (!strcmp(*av,"-un"))
     { op |= LOCK_UN;
       continue;
     }
    if (!strcmp(*av,"-v"))
     { vflag = 1;
       continue;
     }
    fprintf(stderr,"%s: unrecognized option `%s'\n",__progname,*av);
    errs ++;
  }
 if (errs) exit(2);
}

int main(int, char **);
int main(int ac, char **av)
{
 int ec;

 handleargs(ac,av);
 if (flock(fd,op) >= 0) exit(0);
 switch (errno)
  {
#ifdef EAGAIN
    case EAGAIN:
#endif
#if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EAGAIN != EWOULDBLOCK))
    case EWOULDBLOCK:
#endif
       ec = 1;
       break;
    default:
       ec = 2;
       break;
  }
 if (vflag || (ec != 1)) fprintf(stderr,"%s: %s\n",__progname,strerror(errno));
 exit(ec);
}