static FILE *dump(FILE *in, const char *filename, int follow, FILE *out)
{
struct utmp ut;
if (follow)
ignore_result( fseek(in, -10 * sizeof(ut), SEEK_END) );
while (fread(&ut, sizeof(ut), 1, in) == 1)
print_utline(ut, out);
if (!follow)
return in;
#ifdef HAVE_INOTIFY_INIT
if (follow_by_inotify(in, filename, out) == 0)
return NULL; /* file already closed */
else
#endif
/* fallback for systems without inotify or with non-free
* inotify instances */
for (;;) {
while (fread(&ut, sizeof(ut), 1, in) == 1)
print_utline(ut, out);
sleep(1);
}
return in;
}
static void roll_file(const char *filename, off_t *size, FILE *out)
{
FILE *in;
struct stat st;
struct utmp ut;
off_t pos;
if (!(in = fopen(filename, "r")))
err(EXIT_FAILURE, _("cannot open %s"), filename);
if (fstat(fileno(in), &st) == -1)
err(EXIT_FAILURE, _("%s: stat failed"), filename);
if (st.st_size == *size)
goto done;
if (fseek(in, *size, SEEK_SET) != (off_t) -1) {
while (fread(&ut, sizeof(ut), 1, in) == 1)
print_utline(ut, out);
}
pos = ftello(in);
/* If we've successfully read something, use the file position, this
* avoids data duplication. If we read nothing or hit an error,
* reset to the reported size, this handles truncated files.
*/
*size = (pos != -1 && pos != *size) ? pos : st.st_size;
done:
fclose(in);
}
void
dump(FILE *fp, int forever, int oldfmt)
{
struct utmp ut;
struct oldutmp uto;
if (forever)
fseek(fp, -10 * (oldfmt ? sizeof uto : sizeof ut), SEEK_END);
do {
if (oldfmt)
while (fread(&uto, sizeof uto, 1, fp) == 1)
print_utline(oldtonew(uto));
else
while (fread(&ut, sizeof ut, 1, fp) == 1)
print_utline(ut);
if (forever) sleep(1);
} while (forever);
}
