Programmatic way to get variable name in C?

c variables variable-names
Alphaneo picture Alphaneo · Oct 26, 2009 · Viewed 41.1k times · Source

I am developing a tool to dump data from variables. I need to dump the variable name, and also the values.

My solution: Store variable name as a string, and print the "variable name", followed by its value.

Is there any programmatic way to know the variable name?

Answer

Matt Joiner picture Matt Joiner · Oct 26, 2009

You could try something like this:

#define DUMP(varname) fprintf(stderr, "%s = %x", #varname, varname);

I used to use this header I wrote, when I was new to C, it might contain some useful ideas. For example this would allow you to print a C value and provide the format specifier in one (as well as some additional information):

#define TRACE(fmt, var) \
        (error_at_line(0, 0, __FILE__, __LINE__, "%s : " fmt, #var, var))

If you're using C++, you could use the type of the passed value and output it appropriately. I can provide a much more lucrative example for how to "pretty print" variable values if this is the case.

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