[SPCA] Continue summary

semester3/spca/code-examples/00_c/00_basics/02_declarations.c

@@ -1,6 +1,7 @@
 int my_int;              // Allocates memory on the stack.
                          // Variable is global (read / writable by entire program)
 static int my_local_int; // only available locally (in this file)
+extern const char *var;  // Defined in some other file
 const int MY_CONST = 10; // constant (immutable), convention: SCREAM_CASE
 
 enum { ONE, TWO } num; // Enum. ONE will get value 0, TWO has value 1

semester3/spca/code-examples/00_c/01_preprocessor/00_macros.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <stdlib.h>
+#define FOO      BAZ
+#define BAR( x ) ( x + 3 )
+#define SKIP_SPACES( p )                                        \
+    do {                                                        \
+        while ( p > 0 ) { p--; }                                \
+    } while ( 0 )
+#define COMMAND( c ) { #c, c##_command } // Produces { "<val(c)>", "<val(c)>_command" }
+
+#ifdef FOO // If macro is defined, ifndef for if not defined
+    #define COURSE "SPCA"
+#else
+    #define COURSE "Systems Programming and Computer Architecture"
+#endif
+
+#if 1
+    #define OUT HELLO // if statement
+#endif
+
+int main( int argc, char *argv[] ) {
+    int i = 10;
+    SKIP_SPACES( i );
+
+    printf( "%s", COURSE );
+
+    return EXIT_SUCCESS;
+}