aboutsummaryrefslogtreecommitdiff
path: root/coreutils/sum.c
blob: 68a85781625950677eafb26e9891cb140a8c3c60 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* vi: set sw=4 ts=4: */
/*
 * sum -- checksum and count the blocks in a file
 *     Like BSD sum or SysV sum -r, except like SysV sum if -s option is given.
 *
 * Copyright (C) 86, 89, 91, 1995-2002, 2004 Free Software Foundation, Inc.
 * Copyright (C) 2005 by Erik Andersen <andersen@codepoet.org>
 * Copyright (C) 2005 by Mike Frysinger <vapier@gentoo.org>
 *
 * Written by Kayvan Aghaiepour and David MacKenzie
 * Taken from coreutils and turned into a busybox applet by Mike Frysinger
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "busybox.h"

/* 1 if any of the files read were the standard input */
static int have_read_stdin;

/* Calculate and print the rotated checksum and the size in 1K blocks
   of file FILE, or of the standard input if FILE is "-".
   If PRINT_NAME is >1, print FILE next to the checksum and size.
   The checksum varies depending on sizeof (int).
   Return 1 if successful.  */
static int bsd_sum_file(const char *file, int print_name)
{
	FILE *fp;
	int checksum = 0;          /* The checksum mod 2^16. */
	uintmax_t total_bytes = 0; /* The number of bytes. */
	int ch;                    /* Each character read. */
	int ret = 0;

	if (LONE_DASH(file)) {
		fp = stdin;
		have_read_stdin++;
	} else {
		fp = fopen_or_warn(file, "r");
		if (fp == NULL)
			goto out;
	}

	while ((ch = getc(fp)) != EOF) {
		++total_bytes;
		checksum = (checksum >> 1) + ((checksum & 1) << 15);
		checksum += ch;
		checksum &= 0xffff;             /* Keep it within bounds. */
	}

	if (ferror(fp)) {
		bb_perror_msg(file);
		fclose_if_not_stdin(fp);
		goto out;
	}

	if (fclose_if_not_stdin(fp) == EOF) {
		bb_perror_msg(file);
		goto out;
	}
	ret++;
	printf("%05d %5ju ", checksum, (total_bytes+1023)/1024);
	if (print_name > 1)
		puts(file);
	else
		puts("");
out:
	return ret;
}

/* Calculate and print the checksum and the size in 512-byte blocks
   of file FILE, or of the standard input if FILE is "-".
   If PRINT_NAME is >0, print FILE next to the checksum and size.
   Return 1 if successful.  */
#define MY_BUF_SIZE 8192
static int sysv_sum_file(const char *file, int print_name)
{
	RESERVE_CONFIG_BUFFER(buf, MY_BUF_SIZE);
	int fd;
	uintmax_t total_bytes = 0;

	/* The sum of all the input bytes, modulo (UINT_MAX + 1).  */
	unsigned int s = 0;

	if (LONE_DASH(file)) {
		fd = 0;
		have_read_stdin = 1;
	} else {
		fd = open(file, O_RDONLY);
		if (fd == -1)
			goto release_and_ret;
	}

	while (1) {
		size_t bytes_read = safe_read(fd, buf, MY_BUF_SIZE);

		if (bytes_read == 0)
			break;

		if (bytes_read == -1) {
release_and_ret:
			bb_perror_msg(file);
			RELEASE_CONFIG_BUFFER(buf);
			if (NOT_LONE_DASH(file))
				close(fd);
			return 0;
		}

		total_bytes += bytes_read;
		while (bytes_read--)
			s += buf[bytes_read];
	}

	if (NOT_LONE_DASH(file) && close(fd) == -1)
		goto release_and_ret;
	else
		RELEASE_CONFIG_BUFFER(buf);

	{
		int r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
		s = (r & 0xffff) + (r >> 16);

		printf("%d %ju ", s, (total_bytes+511)/512);
	}
	puts(print_name ? file : "");

	return 1;
}

int sum_main(int argc, char **argv)
{
	int flags;
	int ok;
	int (*sum_func)(const char *, int) = bsd_sum_file;

	/* give the bsd func priority over sysv func */
	flags = getopt32(argc, argv, "sr");
	if (flags & 1)
		sum_func = sysv_sum_file;
	if (flags & 2)
		sum_func = bsd_sum_file;

	have_read_stdin = 0;
	if ((argc - optind) == 0)
		ok = sum_func("-", 0);
	else
		for (ok = 1; optind < argc; optind++)
			ok &= sum_func(argv[optind], 1);

	if (have_read_stdin && fclose(stdin) == EOF)
		bb_perror_msg_and_die("-");

	exit(ok ? EXIT_SUCCESS : EXIT_FAILURE);
}