grab sum from coreutils, clean it up, and make it busybox happy

1 files changed, 182 insertions, 0 deletions

diff --git a/coreutils/sum.c b/coreutils/sum.c
new file mode 100644
index 000000000..2618648b2
--- /dev/null
+++ b/coreutils/sum.c
@@ -0,0 +1,182 @@
+/*
+ * 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);
+}