hush/coreutils/sum.c

183 lines
4.6 KiB
C

/*
* 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
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <getopt.h>
#include "libbb.h"
/* 1 if any of the files read were the standard input */
static int have_read_stdin;
/* make a little more readable and avoid using strcmp for just 2 bytes */
#define IS_STDIN(s) (s[0] == '-' && s[1] == '\0')
/* 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)
{
register FILE *fp;
register int checksum = 0; /* The checksum mod 2^16. */
register uintmax_t total_bytes = 0; /* The number of bytes. */
register int ch; /* Each character read. */
if (IS_STDIN(file)) {
fp = stdin;
have_read_stdin = 1;
} else {
fp = fopen(file, "r");
if (fp == NULL) {
bb_perror_msg("%s", file);
return 0;
}
}
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("%s", file);
if (!IS_STDIN(file))
fclose(fp);
return 0;
}
if (!IS_STDIN(file) && fclose(fp) == EOF) {
bb_perror_msg("%s", file);
return 0;
}
printf("%05d %5s", checksum,
make_human_readable_str(total_bytes, 1, 1024));
if (print_name > 1)
printf(" %s", file);
putchar('\n');
return 1;
}
/* 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. */
static int sysv_sum_file(const char *file, int print_name)
{
int fd;
unsigned char buf[8192];
uintmax_t total_bytes = 0;
int r;
int checksum;
/* The sum of all the input bytes, modulo (UINT_MAX + 1). */
unsigned int s = 0;
if (IS_STDIN(file)) {
fd = 0;
have_read_stdin = 1;
} else {
fd = open(file, O_RDONLY);
if (fd == -1) {
bb_perror_msg("%s", file);
return 0;
}
}
while (1) {
size_t i;
size_t bytes_read = safe_read(fd, buf, sizeof(buf));
if (bytes_read == 0)
break;
if (bytes_read == -1) {
bb_perror_msg("%s", file);
if (!IS_STDIN(file))
close(fd);
return 0;
}
for (i = 0; i < bytes_read; i++)
s += buf[i];
total_bytes += bytes_read;
}
if (!IS_STDIN(file) && close(fd) == -1) {
bb_perror_msg("%s", file);
return 0;
}
r = (s & 0xffff) + ((s & 0xffffffff) >> 16);
checksum = (r & 0xffff) + (r >> 16);
printf("%d %s", checksum,
make_human_readable_str(total_bytes, 1, 512));
if (print_name)
printf(" %s", file);
putchar('\n');
return 1;
}
int sum_main(int argc, char **argv)
{
int flags;
int ok;
int files_given;
int (*sum_func)(const char *, int) = bsd_sum_file;
/* give the bsd func priority over sysv func */
flags = bb_getopt_ulflags(argc, argv, "sr");
if (flags & 1)
sum_func = sysv_sum_file;
if (flags & 2)
sum_func = bsd_sum_file;
have_read_stdin = 0;
files_given = argc - optind;
if (files_given <= 0)
ok = sum_func("-", files_given);
else
for (ok = 1; optind < argc; optind++)
ok &= sum_func(argv[optind], files_given);
if (have_read_stdin && fclose(stdin) == EOF)
bb_perror_msg_and_die("-");
exit(ok ? EXIT_SUCCESS : EXIT_FAILURE);
}