Bee wrote: >>>>> - besize template 'aAuU', anything else tempplate I can use to >>>>> prepare fix length data ? - if yes, but how do I assuming the >>>>> block size is? In case, if I write a binary file and I wanna >>>>> use seek. >>>> >>>>You are going to have to explain that in more detail. >>> >>>In case, I am doing something like a log with User v TimesOfSignIn. >>>So, user name will set as 30 char long, and the Signin times is about >>>in scope of a normal integer. I wanna make this a simple DB for this >>>but not a list of single files for each user. So I wanna make this >>>doable for ramdom read write, so, that should be in a binary file. >> >>You want to have a look at DBM files. Read >> perldoc DB_File >>or >> perldoc SDBM_File >> >>Or you may try to install DBD::SQLite. That would give you the full >>power of SQL without having to install anything but the module. >> >> > However, as the file is in a binary, I think there could be a size >> >>>benfit for me to compress the data length. >> >> "Premature optimization is the root of all evil." >> >>How many users are we talking about? Millions? I would not sweat over >>a few KB you might save. > > > Yes, that's very right, I should have to do that with some db modules!!! I > am sorry I missed something to declare here . I just do it as an experiment > to know and learn how pack works in this ways. > > So, I still looking for a pack way to get this job done. Actaully, I am still > quite confuse on what I can expect pack and unpack can giving help to me, > in furture. I guess I would have some light to know what pack is while this > get done.
pack and unpack simply provide a way to translate the bits of a string in a specific way. eg. you can look at a string of bits as a series of 32-bit signed integers or you can look at the same string as a series of 8-bit characters. (It's sort of like a casting operator in C/C++.) It provides a way of looking at or storing data in a very specific way. It's primary use is looking at or creating binary data to be shared with other (C-like) applications. Randy. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] <http://learn.perl.org/> <http://learn.perl.org/first-response>
