1 /* 2 * extend.c --- extend a file so that it has at least a specified 3 * number of blocks. 4 * 5 * Copyright (C) 1993, 1994, 1995 Theodore Ts'o. 6 * 7 * This file may be redistributed under the terms of the GNU Public 8 * License. 9 */ 10 11 #include "config.h" 12 #include <stdio.h> 13 #include <unistd.h> 14 #include <stdlib.h> 15 #include <string.h> 16 #include <sys/types.h> 17 #include <fcntl.h> 18 #include "../misc/nls-enable.h" 19 20 static void usage(char *progname) 21 { 22 fprintf(stderr, _("%s: %s filename nblocks blocksize\n"), 23 progname, progname); 24 exit(1); 25 } 26 27 28 int main(int argc, char **argv) 29 { 30 char *filename; 31 int nblocks, blocksize; 32 int fd; 33 char *block; 34 int ret; 35 36 if (argc != 4) 37 usage(argv[0]); 38 39 filename = argv[1]; 40 nblocks = strtoul(argv[2], 0, 0) - 1; 41 blocksize = strtoul(argv[3], 0, 0); 42 43 if (nblocks < 0) { 44 fprintf(stderr, _("Illegal number of blocks!\n")); 45 exit(1); 46 } 47 48 block = malloc(blocksize); 49 if (block == 0) { 50 fprintf(stderr, _("Couldn't allocate block buffer (size=%d)\n"), 51 blocksize); 52 exit(1); 53 } 54 memset(block, 0, blocksize); 55 56 fd = open(filename, O_RDWR); 57 if (fd < 0) { 58 perror(filename); 59 exit(1); 60 } 61 ret = lseek(fd, nblocks*blocksize, SEEK_SET); 62 if (ret < 0) { 63 perror("lseek"); 64 exit(1); 65 } 66 ret = read(fd, block, blocksize); 67 if (ret < 0) { 68 perror("read"); 69 exit(1); 70 } 71 ret = lseek(fd, nblocks*blocksize, SEEK_SET); 72 if (ret < 0) { 73 perror("lseek #2"); 74 exit(1); 75 } 76 ret = write(fd, block, blocksize); 77 if (ret < 0) { 78 perror("read"); 79 exit(1); 80 } 81 exit(0); 82 } 83
