text: /* vi: set sw=4 ts=4: */
  /*
   * uniq implementation for busybox
   *
   * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
   *
   * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
   */
  
  /* BB_AUDIT SUSv3 compliant */
  /* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
  
  #include "libbb.h"
  
  static const char uniq_opts[] ALIGN1 = "cdu" "f:s:" "cdu\0\1\2\4";
  
  static FILE *xgetoptfile_uniq_s(char **argv, int read0write2)
  {
  	const char *n;
  
  	n = *argv;
  	if (n != NULL) {
  		if ((*n != '-') || n[1]) {
  			return xfopen(n, "r\0w" + read0write2);
  		}
  	}
  	return (read0write2) ? stdout : stdin;
  }
  
  int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int uniq_main(int argc, char **argv)
  {
  	FILE *in, *out;
  	unsigned long dups, skip_fields, skip_chars, i;
  	const char *s0, *e0, *s1, *e1, *input_filename;
  	unsigned opt;
  
  	enum {
  		OPT_c = 0x1,
  		OPT_d = 0x2,
  		OPT_u = 0x4,
  		OPT_f = 0x8,
  		OPT_s = 0x10,
  	};
  
  	skip_fields = skip_chars = 0;
  
  	opt = getopt32(argv, "cduf:s:", &s0, &s1);
  	if (opt & OPT_f)
  		skip_fields = xatoul(s0);
  	if (opt & OPT_s)
  		skip_chars = xatoul(s1);
  	argv += optind;
  
  	input_filename = *argv;
  
  	in = xgetoptfile_uniq_s(argv, 0);
  	if (*argv) {
  		++argv;
  	}
  	out = xgetoptfile_uniq_s(argv, 2);
  	if (*argv && argv[1]) {
  		bb_show_usage();
  	}
  
  	s1 = e1 = NULL;				/* prime the pump */
  
  	do {
  		s0 = s1;
  		e0 = e1;
  		dups = 0;
  
  		/* gnu uniq ignores newlines */
  		while ((s1 = xmalloc_getline(in)) != NULL) {
  			e1 = s1;
  			for (i = skip_fields; i; i--) {
  				e1 = skip_whitespace(e1);
  				e1 = skip_non_whitespace(e1);
  			}
  			for (i = skip_chars; *e1 && i; i--) {
  				++e1;
  			}
  
  			if (!s0 || strcmp(e0, e1)) {
  				break;
  			}
  
  			++dups;		 /* Note: Testing for overflow seems excessive. */
  		}
  
  		if (s0) {
  			if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_e) */
  				fprintf(out, "\0%d " + (opt & 1), dups + 1);
  				fprintf(out, "%s\n", s0);
  			}
  			free((void *)s0);
  		}
  	} while (s1);
  
  	die_if_ferror(in, input_filename);
  
  	fflush_stdout_and_exit(EXIT_SUCCESS);
  }
  