C90: How do I globally initialize this struct in C without C99 extensions

c struct global declare c89
Jack picture Jack · Jul 8, 2011 · Viewed 8.2k times · Source

I was wondering what the best way to initialize this struct is with C90, while still keeping it neat.

In my header file, call it test.h, I have the following struct defined:

 struct s_test_cfg{
      char *a[3];
      char *b[3];
      char *c[3];
 }

Then I have it declared as an extern struct so that I can initialize it globally in the .c file:

 extern struct s_test_cfg test_cfg;

Now in my .c file, I want to be able to declare something like this globally (obviously what I'm about to write is unsupported in C90):

 struct s_test_cfg test_cfg =
 { .a = {"a", "b", "c"},\
   .b = {"d", "e", "f"},\
   .c = {"g", "h", "i"} };

This obviously makes it very neat and transparent as to what you're trying to do. How can I initialize the global struct in my C file that is also as clean as this syntax? Thanks.

Answer

Fred Foo picture Fred Foo · Jul 8, 2011 
struct s_test_cfg test_cfg = {
    { "a", "b", "c" },  /* .a */
    { "d", "e", "f" },  /* .b */
    { "g", "h", "i" },  /* .c */
};

is probably the cleanest option (short of getting yourself a C99 compiler; GCC and Intel C both support C99).

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