1 /*
2 *
3 * Copyright (c) International Business Machines Corp., 2003
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20 /*
21 * FILE : create_datafile.c
22 * PURPOSE : Creates a file of specified size.
23 * HISTORY :
24 * 10/17/2003 Robbie Williamson
25 * -Written
26 */
27
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 #include <unistd.h>
33 #include <fcntl.h>
34 #include <string.h>
35
36 /* set write buffer size to whatever floats your boat. I usually use 1M */
37 #define BSIZE 1048576L
38
main(int argc,char * argv[])39 int main(int argc, char *argv[])
40 {
41 off_t i;
42 long bufnum;
43 char buf[BSIZE];
44 off_t fd;
45
46 if (argc != 3 || atoi(argv[1]) < 1) {
47 printf
48 ("usage:\n\tcreate_file <# of %ld buffers to write> <name of file to create>\n\t ex. # create_file 10 /tmp/testfile\n",
49 BSIZE);
50 exit(3);
51 }
52 bufnum = strtol(argv[1], NULL, 0);
53 printf("Started building a %lu megabyte file\n", bufnum);
54 buf[0] = 'A';
55 for (i = 1; i < BSIZE; i++)
56 buf[i] = buf[i - 1] + 1;
57 buf[BSIZE - 1] = 'Z';
58
59 if ((fd = creat(argv[2], 0755)) == -1)
60 perror("lftest: ");
61
62 for (i = 0; i < bufnum; i++) {
63 if (write(fd, buf, BSIZE) == -1)
64 return -1;
65 else {
66 printf(".");
67 fflush(stdout);
68 }
69 fsync(fd);
70 }
71 close(fd);
72 printf("\nFinished building a %lu megabyte file\n", bufnum);
73 return (0);
74 }
75