[Alibava-general] Segmentation fault

[Daniel C. <da...@ce...>]

Dear all,

we've had some trouble running ALiBaVa DAQ software and consequently the
provided ROOT macros on different PCs. You can verify that a part of the
macros responsible for reading data files (the AsciiRoot class,
specifically the open() method) does so on a read-sizeof-something-bytes
basis. With the first thing to be read being a time stamp saved as
time_t data type specified in the ISO C standard. However, this standard
does not specify any particular size. Usually 32-bit systems use a
32-bit integer or floating type variables for time_t, while 64-bit
systems use 64-bit variables. I believe (maybe someone here can confirm
this or correct me) that the ALiBaVa software uses the same approach
when creating the data files. Therefore, acquiring data on a 32-bit
system and analyzing them on a 64-bit system results in a segmentation
fault. For anyone having the same problem, a quick and dirty solution is
to use:

ifile->read((char *)&_t0, 4*sizeof(char));

instead of 

ifile->read((char *)&_t0, sizeof(time_t));

in the open() method of the AsciiRoot class.


Kind regards,

Daniel Cervenkov
--
Charles University in Prague
Faculty of Mathematics and Physics
Institute of Particle and Nuclear Physics