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 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
