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