C++: Is there a way to determine the file type of a given file?

gubacsek · 06-05-2009, 08:49 AM

Quote:

Originally Posted by jiml8

I am a bit surprised that worked.

Hmm... I tryed your version jiml8, and it is working also. I will compile my program that way in the future.

I have one more question: How is this linking working? If i link libmagic, and compile my program, will it run on machines, where libmagic is not present? I don't understand this part. Do i need the library only at compile time, or it is needed by the program at runtime also?

jiml8 · 06-05-2009, 08:55 AM

You need to study the manpages on the linker (ld).

By default, libraries are dynamically linked in, which means the library must be present on the target system. You can statically link a library (if there is a .a version of it) in which case the contents of the library are added to the executable and the resulting program is self-contained. Usually using dynamic linking is better; smaller executables, less bloat, and protection against future upgrades that might break your statically linked program.

gubacsek · 06-05-2009, 01:48 PM

I understand. I asked because i was trying to decide which version would be better, and more flexible (portable). To use libmagic, or the file and grep version. I will use the dinamically linked libmagic version, and if i give my great and usefull program (

) to someone, i will try the static.
I will read more about this topic...

Many many thanks for your help jiml8, and all of you! I appreciate it very much!
You are the sort of guys, that a starter needs

Have a nice weekend!