sgetopt.c

linux下qmail的源码 本人加了一些注释

/* sgetopt.c, sgetopt.h: (yet another) improved getopt clone, outer layer
D. J. Bernstein, [e-mail].
Depends on subgetopt.h, substdio.h, subfd.h.
No system requirements.
19970208: Cleanups.
931201: Baseline.
No known patent problems.

Documentation in sgetopt.3.
*/

#include "substdio.h"
#include "subfd.h"
#define SGETOPTNOSHORT
#include "sgetopt.h"
#define SUBGETOPTNOSHORT
#include "subgetopt.h"

#define getopt sgetoptmine
#define optind subgetoptind
#define opterr sgetopterr
#define optproblem subgetoptproblem
#define optprogname sgetoptprogname

int opterr = 1;
char *optprogname = 0;

int getopt(argc,argv,opts)
int argc;
char **argv;
char *opts;
{
  int c;
  char *s;

  if (!optprogname) {
    optprogname = *argv;
    if (!optprogname) optprogname = "";
    for (s = optprogname;*s;++s) if (*s == '/') optprogname = s + 1;
  }
  c = subgetopt(argc,argv,opts);
  if (opterr)
    if (c == '?') {
      char chp[2]; chp[0] = optproblem; chp[1] = '\n';
      substdio_puts(subfderr,optprogname);
      if (argv[optind] && (optind < argc))
        substdio_puts(subfderr,": illegal option -- ");
      else
        substdio_puts(subfderr,": option requires an argument -- ");
      substdio_put(subfderr,chp,2);
      substdio_flush(subfderr);
    }
  return c;
}