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+/*
+ * Copyright (C) 2007, 2008 Nokia Corporation
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * This file contains various common stuff.
+ *
+ * Authors: Artem Bityutskiy
+ * Adrian Hunter
+ */
+
+#define PROGRAM_NAME "mtd-utils"
+
+#include <sys/time.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "common.h"
+
+/**
+ * get_multiplier - convert size specifier to an integer multiplier.
+ * @str: the size specifier string
+ *
+ * This function parses the @str size specifier, which may be one of
+ * 'KiB', 'MiB', or 'GiB' into an integer multiplier. Returns positive
+ * size multiplier in case of success and %-1 in case of failure.
+ */
+static int get_multiplier(const char *str)
+{
+ if (!str)
+ return 1;
+
+ /* Remove spaces before the specifier */
+ while (*str == ' ' || *str == '\t')
+ str += 1;
+
+ if (!strcmp(str, "KiB"))
+ return 1024;
+ if (!strcmp(str, "MiB"))
+ return 1024 * 1024;
+ if (!strcmp(str, "GiB"))
+ return 1024 * 1024 * 1024;
+
+ return -1;
+}
+
+/**
+ * util_get_bytes - convert a string containing amount of bytes into an
+ * integer
+ * @str: string to convert
+ *
+ * This function parses @str which may have one of 'KiB', 'MiB', or 'GiB'
+ * size specifiers. Returns positive amount of bytes in case of success and %-1
+ * in case of failure.
+ */
+long long util_get_bytes(const char *str)
+{
+ char *endp;
+ long long bytes = strtoull(str, &endp, 0);
+
+ if (endp == str || bytes < 0) {
+ fprintf(stderr, "incorrect amount of bytes: \"%s\"\n", str);
+ return -1;
+ }
+
+ if (*endp != '\0') {
+ int mult = get_multiplier(endp);
+
+ if (mult == -1) {
+ fprintf(stderr, "bad size specifier: \"%s\" - "
+ "should be 'KiB', 'MiB' or 'GiB'\n", endp);
+ return -1;
+ }
+ bytes *= mult;
+ }
+
+ return bytes;
+}
+
+/**
+ * util_print_bytes - print bytes.
+ * @bytes: variable to print
+ * @bracket: whether brackets have to be put or not
+ *
+ * This is a helper function which prints amount of bytes in a human-readable
+ * form, i.e., it prints the exact amount of bytes following by the approximate
+ * amount of Kilobytes, Megabytes, or Gigabytes, depending on how big @bytes
+ * is.
+ */
+void util_print_bytes(long long bytes, int bracket)
+{
+ const char *p;
+
+ if (bracket)
+ p = " (";
+ else
+ p = ", ";
+
+ printf("%lld bytes", bytes);
+
+ if (bytes > 1024 * 1024 * 1024)
+ printf("%s%.1f GiB", p, (double)bytes / (1024 * 1024 * 1024));
+ else if (bytes > 1024 * 1024)
+ printf("%s%.1f MiB", p, (double)bytes / (1024 * 1024));
+ else if (bytes > 1024 && bytes != 0)
+ printf("%s%.1f KiB", p, (double)bytes / 1024);
+ else
+ return;
+
+ if (bracket)
+ printf(")");
+}
+
+/**
+ * util_srand - randomly seed the standard pseudo-random generator.
+ *
+ * This helper function seeds the standard libc pseudo-random generator with a
+ * more or less random value to make sure the 'rand()' call does not return the
+ * same sequence every time UBI utilities run. Returns zero in case of success
+ * and a %-1 in case of error.
+ */
+int util_srand(void)
+{
+ struct timeval tv;
+ struct timezone tz;
+ unsigned int seed;
+
+ /*
+ * Just assume that a combination of the PID + current time is a
+ * reasonably random number.
+ */
+ if (gettimeofday(&tv, &tz))
+ return -1;
+
+ seed = (unsigned int)tv.tv_sec;
+ seed += (unsigned int)tv.tv_usec;
+ seed *= getpid();
+ seed %= RAND_MAX;
+ srand(seed);
+ return 0;
+}