off_t gt_file_size(const char *file)
{
struct stat sb;
int fd;
gt_assert(file);
fd = gt_xopen(file, O_RDONLY, 0);
gt_xfstat(fd, &sb);
gt_xclose(fd);
return sb.st_size;
}
int gt_mmapandread(int argc, const char **argv, GtError *err)
{
int i, fd, parsed_args;
void *map;
struct stat sb;
unsigned long long j;
unsigned int byte = 0;
gt_error_check(err);
/* option parsing */
switch (parse_options(&parsed_args, argc, argv, err)) {
case GT_OPTION_PARSER_OK: break;
case GT_OPTION_PARSER_ERROR: return -1;
case GT_OPTION_PARSER_REQUESTS_EXIT: return 0;
}
/* iterate over all files */
for (i = parsed_args; i < argc; i++) {
/* open file */
fd = gt_xopen(argv[i], O_RDONLY, 0);
/* get file statistics */
gt_xfstat(fd, &sb);
if (sb.st_size == 0)
printf("file \"%s\" is empty\n", argv[i]);
else if (!(sb.st_mode & S_IFREG))
printf("\"%s\" is not a regular file\n", argv[i]);
else {
/* map file */
map = gt_xmmap(0, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
/* read file */
printf("reading file \"%s\"\n", argv[i]);
j = 0;
gt_progressbar_start(&j, (unsigned long long) sb.st_size);
for (; j < (unsigned long long) sb.st_size; j++)
byte |= (unsigned int) ((char*) map)[j];
gt_progressbar_stop();
/* unmap file */
gt_xmunmap(map, sb.st_size);
}
/* close file */
gt_xclose(fd);
}
if (!byte)
printf("all read files contained only null characters\n");
return 0;
}
off_t gt_file_estimate_size(const char *file)
{
off_t size;
struct stat sb;
GtFileMode gfm;
int fd;
gt_assert(file);
fd = gt_xopen(file, O_RDONLY, 0);
gt_xfstat(fd, &sb);
gfm = gt_file_mode_determine(file);
if (gfm == GT_FILE_MODE_UNCOMPRESSED)
size = sb.st_size;
else
size = sb.st_size * 4; /* expected compression rate for sequence is 0.25 */
gt_xclose(fd);
return size;
}
