-#ifdef __VISUALC__
- int iRc = _filelength(m_fd);
-#else // !VC++
- int iRc = wxTell(m_fd);
- if ( iRc != -1 ) {
- // @ have to use const_cast :-(
- int iLen = ((wxFile *)this)->SeekEnd();
- if ( iLen != -1 ) {
+ // we use a special method for Linux systems where files in sysfs (i.e.
+ // those under /sys typically) return length of 4096 bytes even when
+ // they're much smaller -- this is a problem as it results in errors later
+ // when we try reading 4KB from them
+#ifdef __LINUX__
+ struct stat st;
+ if ( fstat(m_fd, &st) == 0 )
+ {
+ // returning 0 for the special files indicates to the caller that they
+ // are not seekable
+ return st.st_blocks ? st.st_size : 0;
+ }
+ //else: failed to stat, try the normal method
+#endif // __LINUX__
+
+ wxFileOffset iRc = Tell();
+ if ( iRc != wxInvalidOffset ) {
+ // have to use const_cast :-(
+ wxFileOffset iLen = ((wxFile *)this)->SeekEnd();
+ if ( iLen != wxInvalidOffset ) {