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Diffstat (limited to 'lib/common.c')
| -rw-r--r-- | lib/common.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/lib/common.c b/lib/common.c new file mode 100644 index 0000000..69b03b3 --- /dev/null +++ b/lib/common.c @@ -0,0 +1,158 @@ +/* + * 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; +} |