busybox/editors/cmp.c

/* vi: set sw=4 ts=4: */
/*
 * Mini cmp implementation for busybox
 *
 * Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */

#include "libbb.h"

static const char fmt_eof[] ALIGN1 = "cmp: EOF on %s\n";
static const char fmt_differ[] ALIGN1 = "%s %s differ: char %"OFF_FMT"u, line %u\n";
// This fmt_l_opt uses gnu-isms.  SUSv3 would be "%.0s%.0s%"OFF_FMT"u %o %o\n"
static const char fmt_l_opt[] ALIGN1 = "%.0s%.0s%"OFF_FMT"u %3o %3o\n";

static const char opt_chars[] ALIGN1 = "sl";
#define CMP_OPT_s (1<<0)
#define CMP_OPT_l (1<<1)

int cmp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cmp_main(int argc UNUSED_PARAM, char **argv)
{
	FILE *fp1, *fp2, *outfile = stdout;
	const char *filename1, *filename2 = "-";
	off_t skip1 = 0, skip2 = 0, char_pos = 0;
	int line_pos = 1; /* Hopefully won't overflow... */
	const char *fmt;
	int c1, c2;
	unsigned opt;
	int retval = 0;

	xfunc_error_retval = 2;	/* 1 is returned if files are different. */

	opt_complementary = "-1"
			IF_DESKTOP(":?4")
			IF_NOT_DESKTOP(":?2")
			":l--s:s--l";
	opt = getopt32(argv, opt_chars);
	argv += optind;

	filename1 = *argv;
	fp1 = xfopen_stdin(filename1);

	if (*++argv) {
		filename2 = *argv;
		if (ENABLE_DESKTOP && *++argv) {
			skip1 = XATOOFF(*argv);
			if (*++argv) {
				skip2 = XATOOFF(*argv);
			}
		}
	}

	fp2 = xfopen_stdin(filename2);
	if (fp1 == fp2) {		/* Paranoia check... stdin == stdin? */
		/* Note that we don't bother reading stdin.  Neither does gnu wc.
		 * But perhaps we should, so that other apps down the chain don't
		 * get the input.  Consider 'echo hello | (cmp - - && cat -)'.
		 */
		return 0;
	}

	if (opt & CMP_OPT_l)
		fmt = fmt_l_opt;
	else
		fmt = fmt_differ;

	if (ENABLE_DESKTOP) {
		while (skip1) { getc(fp1); skip1--; }
		while (skip2) { getc(fp2); skip2--; }
	}
	do {
		c1 = getc(fp1);
		c2 = getc(fp2);
		++char_pos;
		if (c1 != c2) {			/* Remember: a read error may have occurred. */
			retval = 1;		/* But assume the files are different for now. */
			if (c2 == EOF) {
				/* We know that fp1 isn't at EOF or in an error state.  But to
				 * save space below, things are setup to expect an EOF in fp1
				 * if an EOF occurred.  So, swap things around.
				 */
				fp1 = fp2;
				filename1 = filename2;
				c1 = c2;
			}
			if (c1 == EOF) {
				die_if_ferror(fp1, filename1);
				fmt = fmt_eof;	/* Well, no error, so it must really be EOF. */
				outfile = stderr;
				/* There may have been output to stdout (option -l), so
				 * make sure we fflush before writing to stderr. */
				fflush_all();
			}
			if (!(opt & CMP_OPT_s)) {
				if (opt & CMP_OPT_l) {
					line_pos = c1;	/* line_pos is unused in the -l case. */
				}
				fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
				if (opt) {	/* This must be -l since not -s. */
					/* If we encountered an EOF,
					 * the while check will catch it. */
					continue;
				}
			}
			break;
		}
		if (c1 == '\n') {
			++line_pos;
		}
	} while (c1 != EOF);

	die_if_ferror(fp1, filename1);
	die_if_ferror(fp2, filename2);

	fflush_stdout_and_exit(retval);
}
1	niro	816	/* vi: set sw=4 ts=4: */
2			/*
3			* Mini cmp implementation for busybox
4			*
5			* Copyright (C) 2000,2001 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
6			*
7			* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8			*/
9
10			/* BB_AUDIT SUSv3 (virtually) compliant -- uses nicer GNU format for -l. */
11			/* http://www.opengroup.org/onlinepubs/007904975/utilities/cmp.html */
12
13			#include "libbb.h"
14
15			static const char fmt_eof[] ALIGN1 = "cmp: EOF on %s\n";
16	niro	984	static const char fmt_differ[] ALIGN1 = "%s %s differ: char %"OFF_FMT"u, line %u\n";
17			// This fmt_l_opt uses gnu-isms. SUSv3 would be "%.0s%.0s%"OFF_FMT"u %o %o\n"
18			static const char fmt_l_opt[] ALIGN1 = "%.0s%.0s%"OFF_FMT"u %3o %3o\n";
19	niro	816
20			static const char opt_chars[] ALIGN1 = "sl";
21			#define CMP_OPT_s (1<<0)
22			#define CMP_OPT_l (1<<1)
23
24			int cmp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
25			int cmp_main(int argc UNUSED_PARAM, char **argv)
26			{
27			FILE fp1, fp2, *outfile = stdout;
28			const char filename1, filename2 = "-";
29	niro	1123	off_t skip1 = 0, skip2 = 0, char_pos = 0;
30	niro	816	int line_pos = 1; /* Hopefully won't overflow... */
31			const char *fmt;
32			int c1, c2;
33			unsigned opt;
34			int retval = 0;
35
36			xfunc_error_retval = 2; /* 1 is returned if files are different. */
37
38			opt_complementary = "-1"
39	niro	984	IF_DESKTOP(":?4")
40			IF_NOT_DESKTOP(":?2")
41	niro	816	":l--s:s--l";
42			opt = getopt32(argv, opt_chars);
43			argv += optind;
44
45			filename1 = *argv;
46			fp1 = xfopen_stdin(filename1);
47
48			if (*++argv) {
49			filename2 = *argv;
50	niro	1123	if (ENABLE_DESKTOP && *++argv) {
51	niro	816	skip1 = XATOOFF(*argv);
52			if (*++argv) {
53			skip2 = XATOOFF(*argv);
54			}
55			}
56			}
57
58			fp2 = xfopen_stdin(filename2);
59			if (fp1 == fp2) { /* Paranoia check... stdin == stdin? */
60			/* Note that we don't bother reading stdin. Neither does gnu wc.
61			* But perhaps we should, so that other apps down the chain don't
62			* get the input. Consider 'echo hello \| (cmp - - && cat -)'.
63			*/
64			return 0;
65			}
66
67			if (opt & CMP_OPT_l)
68			fmt = fmt_l_opt;
69			else
70			fmt = fmt_differ;
71
72	niro	1123	if (ENABLE_DESKTOP) {
73			while (skip1) { getc(fp1); skip1--; }
74			while (skip2) { getc(fp2); skip2--; }
75			}
76	niro	816	do {
77			c1 = getc(fp1);
78			c2 = getc(fp2);
79			++char_pos;
80			if (c1 != c2) { /* Remember: a read error may have occurred. */
81			retval = 1; /* But assume the files are different for now. */
82			if (c2 == EOF) {
83			/* We know that fp1 isn't at EOF or in an error state. But to
84			* save space below, things are setup to expect an EOF in fp1
85			* if an EOF occurred. So, swap things around.
86			*/
87			fp1 = fp2;
88			filename1 = filename2;
89			c1 = c2;
90			}
91			if (c1 == EOF) {
92			die_if_ferror(fp1, filename1);
93			fmt = fmt_eof; /* Well, no error, so it must really be EOF. */
94			outfile = stderr;
95			/* There may have been output to stdout (option -l), so
96			* make sure we fflush before writing to stderr. */
97	niro	984	fflush_all();
98	niro	816	}
99			if (!(opt & CMP_OPT_s)) {
100			if (opt & CMP_OPT_l) {
101			line_pos = c1; /* line_pos is unused in the -l case. */
102			}
103			fprintf(outfile, fmt, filename1, filename2, char_pos, line_pos, c2);
104			if (opt) { /* This must be -l since not -s. */
105			/* If we encountered an EOF,
106			* the while check will catch it. */
107			continue;
108			}
109			}
110			break;
111			}
112			if (c1 == '\n') {
113			++line_pos;
114			}
115			} while (c1 != EOF);
116
117			die_if_ferror(fp1, filename1);
118			die_if_ferror(fp2, filename2);
119
120			fflush_stdout_and_exit(retval);
121			}