Beispiele 21.11.2019

20191121/blink-11.c

@@ -19,7 +19,7 @@ int main (void)
   EIMSK = 1 << INT0;  /* INT0 einschalten */
   sei ();
   DDRD = 0xfb;   /* binär: 1111 1011 */
-  PORTD = 0x40;  /* binär: 0100 0000 */
+  PORTD = 0x60;  /* binär: 0100 0000 */
   while (1)
     {
       while (!key_pressed)

20191121/blink-7.c

@@ -14,7 +14,7 @@ int main (void)
   EIMSK = 1 << INT0;  /* INT0 einschalten */
   sei ();
   DDRD = 0xfb;   /* binär: 1111 1011 */
-  PORTD = 0x40;  /* binär: 0100 0000 */
+  PORTD = 0x60;  /* binär: 0110 0000 */
   while (1);
   return 0;
 }

20191121/blink-9.c

@@ -19,7 +19,7 @@ int main (void)
   EIMSK = 1 << INT0;  /* INT0 einschalten */
   sei ();
   DDRD = 0xfb;   /* binär: 1111 1011 */
-  PORTD = 0x40;  /* binär: 0100 0000 */
+  PORTD = 0x60;  /* binär: 0100 0000 */
   while (1)
     {
       while (!key_pressed)

20191121/hello-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  return 0;
+}

20191121/hello-2.c

+extern int printf (const char *__restrict __format, ...);
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  return 0;
+}

20191121/hello-3.c

+extern int pruzzel (const char *__restrict __format, ...);
+
+int main (void)
+{
+  pruzzel ("Hello, world!\n");
+  return 0;
+}

20191121/hello-4.c

+int pruzzel (const char *bla)
+{
+  printf ("%s", bla);
+  return 42;
+}
+
+int main (void)
+{
+  pruzzel ("Hello, world!\n");
+  return 0;
+}

20191121/hello-5.c

+extern int pruzzel (const char *bla);
+
+int main (void)
+{
+  pruzzel ("Hello, world!\n");
+  return 0;
+}

20191121/hello-6.c

+#include "pruzzel.h"
+
+int main (void)
+{
+  pruzzel ("Hello, world!\n");
+  return 0;
+}

20191121/hexe.h

+eine kleine Hexe.

20191121/maerchen.c

+Vor langer, langer Zeit
+gab es einmal
+#include "hexe.h"
+Die lebte in einem Wald.

20191121/pruzzel-1.txt

+cassini/home/peter/bo/2019ws/hp/20191121> cat hello-5.c
+extern int pruzzel (const char *bla);
+
+int main (void)
+{
+  pruzzel ("Hello, world!\n");
+  return 0;
+}
+cassini/home/peter/bo/2019ws/hp/20191121> cat pruzzel.c
+#include <stdio.h>
+
+int pruzzel (const char *bla)
+{
+  printf ("%s", bla);
+  return 42;
+}
+cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O pruzzel.c -o pruzzel
+/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o: In function `_start':
+(.text+0x20): undefined reference to `main'
+collect2: error: ld returned 1 exit status
+cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O hello-5.c -o hello-5
+/tmp/ccfdwwB5.o: In function `main':
+hello-5.c:(.text+0xc): undefined reference to `pruzzel'
+collect2: error: ld returned 1 exit status
+cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O hello-5.c pruzzel.c -o hello-5
+cassini/home/peter/bo/2019ws/hp/20191121> ./hello-5
+Hello, world!
+cassini/home/peter/bo/2019ws/hp/20191121>

20191121/pruzzel-2.txt

+cassini/home/peter/bo/2019ws/hp/20191121> cat hello-6.c
+#include "pruzzel.h"
+
+int main (void)
+{
+  pruzzel ("Hello, world!\n");
+  return 0;
+}
+cassini/home/peter/bo/2019ws/hp/20191121> gcc -Wall -O hello-6.c pruzzel.c -o hello-6cassini/home/peter/bo/2019ws/hp/20191121> ./hello-
+cassini/home/peter/bo/2019ws/hp/20191121> ./hello-6
+Hello, world!
+cassini/home/peter/bo/2019ws/hp/20191121> cat pruzzel.c
+#include <stdio.h>
+
+int pruzzel (const char *bla)
+{
+  printf ("%s", bla);
+  return 42;
+}
+cassini/home/peter/bo/2019ws/hp/20191121> cat pruzzel.h
+extern int pruzzel (const char *bla);
+cassini/home/peter/bo/2019ws/hp/20191121>

20191121/pruzzel.c

+#include <stdio.h>
+
+int pruzzel (const char *bla)
+{
+  printf ("%s", bla);
+  return 42;
+}

20191121/pruzzel.h

+extern int pruzzel (const char *bla);