source: mainline/uspace/app/filegen/filegen.c@ db9aa04

/** @addtogroup filecheck
 * @{
 */

/**
 * @file        filecrc.c
 * @brief       Tool for generating file with random data
 *
 */


#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/time.h>
#include "crc32.h"

#define NAME    "filegen"
#define VERSION "0.0.1"

#define BUFFERSIZE 256


static void print_help(void);


int main(int argc, char **argv) {
        int rc;
        uint64_t size = 0;
        
        if (argc < 3) {
                print_help();
                return 0;
        }
        
        int fd = open(argv[1], O_WRONLY | O_CREAT);
        if (fd < 0) {
                printf("Unable to open %s for writing\n", argv[1]);
                return 1;
        }
        
        rc = str_uint64(argv[2], NULL, 10, true, &size);
        if (rc != EOK) {
                printf("Cannot convert size to number\n");
                return 1;
        }
        
        struct timeval tv;      
        gettimeofday(&tv, NULL);
        srandom(tv.tv_sec + tv.tv_usec / 100000);       

        uint64_t i=0, pbuf=0;
        uint32_t crc=~0;
        char buf[BUFFERSIZE];
        
        while (i<size) {
                pbuf=0;
                while (i<size && pbuf<BUFFERSIZE) {
                        buf[pbuf] = rand() % 255;
                        i++;
                        pbuf++;
                }
                if (pbuf) {
                        crc32(buf, pbuf, &crc);
                        write(fd, buf, pbuf);
                }
        }
        
        close(fd);
        crc = ~crc;
        printf("%s : %x\n", argv[1], crc);

        return 0;
}


/* Displays help for filegen */
static void print_help(void)
{
        printf(
           "Usage:  %s <file> <size in bytes>\n",
           NAME);
}


/**
 * @}
 */