Hi,
I have a C header file which have arrays of predefined(known) structure type. But i dont have names of arrays and their size. when i include that file and compile my application, i want to know the names and sizesof those arrays.
purpose of application is to get the content of those arrays and to explain it in descriptive words instead of hex numbers.ofcourse this can be done by file pointers and reading also with out header file inclusion, but as i am working in C, once compiled, those variables are in my address space in i include header file.

any suggestion to get variable names is welcome.

yours vijay

That can't really be done in C without e.g. parsing the header file.

Are you speaking of the content of the file, or the memory content at runtime?

For the former I remember General Edit for Mac, and there might be something similar for Linux.

Thanks Mr Graham and Mr Reuti,

I want to get whats there in those array elements in run time Just like GDB and Valgrind pointing to particular variable or function in case of any fault. That indicates me we may be able to read what variables are there in process address space when it is running. similarly can we know address of arrays and number of elements in it.


Hope that this will clarify my requirement.

yours vijay

Do you know python? If so, gdb has an API for python. I don't know python, but this looks like a good start:
http://sourceware.org/gdb/wiki/PythonGdbTutorial

Kevin Barry

Your requirement was quite clear from the beginning. valgrind doesn't (to my knowledge...?) tell you the types of variables etc. and gdb does exactly what I said before - it uses debugging information to find the source files the program uses and (I believe) a program called addr2line (see `man 1 addr2line') to tell what line of the program it is.

At run-time, variables in C don't have "types" - they are simply memory addresses you use as if they were certain types. These addresses are known as "symbols" in the ELF file you run. You can take the address of variables you're interested in or even parse the ELF file to find the symbols, but finding the type of them at run-time will require you to find the source/header file and parse it.

Go with another method, like ta0kira suggests.