/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Case Larsen.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)uniq.c	5.1 (Berkeley) 05/28/89";
#endif /* not lint */

#include <stdio.h>
#include <ctype.h>

int cflag, dflag, uflag;
int numchars, numfields, repeats;

#define	MAXLINELEN	(2048 + 1)

main (argc,argv)
	int argc;
	char **argv;
{
	extern int optind;
	FILE *ifp, *ofp, *file();
	int ch;
	register char *t1, *t2;
	char *prevline, *thisline, *malloc(), *skip();

	while ((ch = getopt(argc, argv, "-cdu123456789")) != EOF)
		switch (ch) {
		case '-':
			--optind;
			goto done;
		case 'c':
			cflag = 1;
			break;
		case 'd':
			dflag = 1;
			break;
		case 'u':
			uflag = 1;
			break;
		/*
		 * since -n is a valid option that could be picked up by
		 * getopt, but is better handled by the +n and -n code, we
		 * break out.
		 */
		case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			--optind;
			goto done;
		case '?':
		default:
			usage();
	}

done:	argc -= optind;
	argv +=optind;

	/* if no flags are set, default is -d -u */
	if (cflag) {
		if (dflag || uflag)
			usage();
	} else if (!dflag && !uflag)
		dflag = uflag = 1;

	/* because of the +, getopt is messed up */
	for (; **argv == '+' || **argv == '-'; ++argv, --argc)
		switch (**argv) {
		case '+':
			if ((numchars = atoi(*argv + 1)) < 0)
				goto negerr;
			break;
		case '-':
			if ((numfields = atoi(*argv + 1)) < 0) {
negerr:				(void)fprintf(stderr,
				    "uniq: negative field/char skip value.\n");
				usage();
			}
			break;
		}
    
	switch(argc) {
	case 0:
		ifp = stdin;
		ofp = stdout;
		break;
	case 1:
		ifp = file(argv[0], "r");
		ofp = stdout;
		break;
	case 2:
		ifp = file(argv[0], "r");
		ofp = file(argv[1], "w");
		break;
	default:
		usage();
	}

	prevline = malloc(MAXLINELEN);
	thisline = malloc(MAXLINELEN);
	(void)fgets(prevline, MAXLINELEN, ifp);

	while (fgets(thisline, MAXLINELEN, ifp)) {
		/* if requested get the chosen fields + character offsets */
		if (numfields || numchars) {
			t1 = skip(thisline);
			t2 = skip(prevline);
		} else {
			t1 = thisline;
			t2 = prevline;
		}

		/* if different, print; set previous to new value */
		if (strcmp(t1, t2)) {
			show(ofp, prevline);
			t1 = prevline;
			prevline = thisline;
			thisline = t1;
			repeats = 0;
		}
		else
			++repeats;
	}
	show(ofp, prevline);
	exit(0);
}

/*
 * show --
 *	output a line depending on the flags and number of repetitions
 *	of the line.
 */
show(ofp, str)
	FILE *ofp;
	char *str;
{
	if (cflag)
		(void)fprintf(ofp, "%4d %s", repeats + 1, str);
	if (dflag && repeats || uflag && !repeats)
		(void)fprintf(ofp, "%s", str);
}

char *
skip(str)
	register char *str;
{
	register int infield, nchars, nfields;

	for (nfields = numfields, infield = 0; nfields && *str; ++str)
		if (isspace(*str)) {
			if (infield) {
				infield = 0;
				--nfields;
			}
		} else if (!infield)
			infield = 1;
	for (nchars = numchars; nchars-- && *str; ++str);
	return(str);
}

FILE *
file(name, mode)
	char *name, *mode;
{
	FILE *fp;

	if (!(fp = fopen(name, mode))) {
		(void)fprintf(stderr, "uniq: can't open %s.\n", name);
		exit(1);
	}
	return(fp);
}

usage()
{
	(void)fprintf(stderr,
	    "usage: uniq [-c | -du] [- #fields] [+ #chars] [input [output]]\n");
	exit(1);
}