1/* vi: set sw=4 ts=4: */
2/*
3 * Mini comm implementation for busybox
4 *
5 * Copyright (C) 2005 by Robert Sullivan <cogito.ergo.cogito@gmail.com>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
10#include "libbb.h"
11
12#define COMM_OPT_1 (1 << 0)
13#define COMM_OPT_2 (1 << 1)
14#define COMM_OPT_3 (1 << 2)
15
16/* writeline outputs the input given, appropriately aligned according to class */
17static void writeline(char *line, int class)
18{
19	int flags = option_mask32;
20	if (class == 0) {
21		if (flags & COMM_OPT_1)
22			return;
23	} else if (class == 1) {
24		if (flags & COMM_OPT_2)
25			return;
26		if (!(flags & COMM_OPT_1))
27			putchar('\t');
28	} else /*if (class == 2)*/ {
29		if (flags & COMM_OPT_3)
30			return;
31		if (!(flags & COMM_OPT_1))
32			putchar('\t');
33		if (!(flags & COMM_OPT_2))
34			putchar('\t');
35	}
36	puts(line);
37}
38
39int comm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
40int comm_main(int argc UNUSED_PARAM, char **argv)
41{
42	char *thisline[2];
43	FILE *stream[2];
44	int i;
45	int order;
46
47	opt_complementary = "=2";
48	getopt32(argv, "123");
49	argv += optind;
50
51	for (i = 0; i < 2; ++i) {
52		stream[i] = xfopen_stdin(argv[i]);
53	}
54
55	order = 0;
56	thisline[1] = thisline[0] = NULL;
57	while (1) {
58		if (order <= 0) {
59			free(thisline[0]);
60			thisline[0] = xmalloc_fgetline(stream[0]);
61		}
62		if (order >= 0) {
63			free(thisline[1]);
64			thisline[1] = xmalloc_fgetline(stream[1]);
65		}
66
67		i = !thisline[0] + (!thisline[1] << 1);
68		if (i)
69			break;
70		order = strcmp(thisline[0], thisline[1]);
71
72		if (order >= 0)
73			writeline(thisline[1], order ? 1 : 2);
74		else
75			writeline(thisline[0], 0);
76	}
77
78	/* EOF at least on one of the streams */
79	i &= 1;
80	if (thisline[i]) {
81		/* stream[i] is not at EOF yet */
82		/* we did not print thisline[i] yet */
83		char *p = thisline[i];
84		writeline(p, i);
85		while (1) {
86			free(p);
87			p = xmalloc_fgetline(stream[i]);
88			if (!p)
89				break;
90			writeline(p, i);
91		}
92	}
93
94	if (ENABLE_FEATURE_CLEAN_UP) {
95		fclose(stream[0]);
96		fclose(stream[1]);
97	}
98
99	return EXIT_SUCCESS;
100}
101