Question

I have some c code to concatenate a string.

char str_cat[strlen(str1) + strlen(str2) + 1];

How do I check the sizeof str_cat in gdb? Right now it reports 0 with:

print sizeof(str_cat)

It does print the string, but how do I print it showing the null character?

Let me reword, how do I verify that str_cat is the proper size and has enough space?

Answer 1

char str_cat[strlen(str1) + strlen(str2) + 1];

How do I check the sizeof str_cat in gdb? Right now it reports 0 with:

str_cat is a variable length array. Apparently gdb does not how to deal with variable length arrays.

There is an open ticket here regarding this issue:
http://sourceware.org/bugzilla/show_bug.cgi?id=9663

it mentions an existing patch but at least my 2012 version 7.4 of gdb does not include it.