Beispielprogramme und Praktikumstermine 23.10.2017

20171023/fhello.txt

+Hello, world!

20171023/files-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  FILE *f = fopen ("fhello.txt", "w");
+  fprintf (f, "Hello, world!\n");
+  fclose (f);
+  return 0;
+}

20171023/files-2.c

+#include <stdio.h>
+
+int main (void)
+{
+  FILE *f = fopen ("fhello.txt", "w");
+  if (f)
+    {
+      fprintf (f, "Hello, world!\n");
+      fclose (f);
+    }
+  return 0;
+}

20171023/files-3.c

+#include <stdio.h>
+#include <errno.h>
+
+int main (void)
+{
+  FILE *f = fopen ("fhello.txt", "w");
+  if (f)
+    {
+      fprintf (f, "Hello, world!\n");
+      fclose (f);
+    }
+  else
+    fprintf (stderr, "error #%d\n", errno);
+  return 0;
+}

20171023/files-4.c

+#include <stdio.h>
+#include <errno.h>
+#include <error.h>
+
+int main (void)
+{
+  FILE *f = fopen ("fhello.txt", "w");
+  if (!f)
+    error (1, errno, "cannot open file");
+  fprintf (f, "Hello, world!\n");
+  fclose (f);
+  return 0;
+}

20171023/files-5.c

+#include <stdio.h>
+#include <errno.h>
+#include <error.h>
+
+int main (void)
+{
+  FILE *f = fopen ("fhello.txt", "w");
+  if (!f)
+    error (errno, errno, "cannot open file");
+  fprintf (f, "Hello, world!\n");
+  fclose (f);
+  return 0;
+}

20171023/praktikum.txt

+PRAKTIKUMSTERMINE
+=================
+
+
+
+Mi 08.11.2017
+Mi 15.11.2017
+
+(Versuch 2)

20171023/strings-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  char hello_world[] = "Hello, world!\n";
+  int i = 0;
+  while (hello_world[i])
+    printf ("%d", hello_world[i++]);
+  return 0;
+}

20171023/strings-10.c

+#include <stdio.h>
+
+int main (void)
+{
+  char p[] = "Hello!\n";
+  p[1] = 'a';
+  printf ("%s", p);
+  return 0;
+}

20171023/strings-11.c

+#include <stdio.h>
+
+int main (void)
+{
+  const char *p = "Hello!\n";
+  p[1] = 'a';
+  printf ("%s", p);
+  return 0;
+}

20171023/strings-2.c

+#include <stdio.h>
+
+int main (void)
+{
+  char hello_world[] = "Hello, world!\n";
+  int i = 0;
+  while (hello_world[i])
+    printf ("%c", hello_world[i++]);
+  return 0;
+}

20171023/strings-3.c

+#include <stdio.h>
+
+int main (void)
+{
+  char hello_world[] = { 72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33, 10, 0 };
+  int i = 0;
+  while (hello_world[i])
+    printf ("%c", hello_world[i++]);
+  return 0;
+}

20171023/strings-4.c

+#include <stdio.h>
+
+int main (void)
+{
+  char hello_world[] = { 72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33, 10 };
+  int i = 0;
+  while (hello_world[i])
+    printf ("%c", hello_world[i++]);
+  return 0;
+}

20171023/strings-5.c

+#include <stdio.h>
+
+int main (void)
+{
+  int hello_world[] = "Hello, world!\n";
+  int i = 0;
+  while (hello_world[i])
+    printf ("%c", hello_world[i++]);
+  return 0;
+}

20171023/strings-6.c

+#include <stdio.h>
+
+int main (void)
+{
+  char hello_world[] = "Hello, world!\n";
+  char *p = hello_world;
+  while (*p)
+    printf ("%c", *p++);
+  return 0;
+}

20171023/strings-7.c

+#include <stdio.h>
+
+int main (void)
+{
+  char *p = "Hello, world!\n";
+  while (*p)
+    printf ("%c", *p++);
+  return 0;
+}

20171023/strings-8.c

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

20171023/strings-9.c

+#include <stdio.h>
+
+int main (void)
+{
+  char *p = "Hello!\n";
+  p[1] = 'a';
+  printf ("%s", p);
+  return 0;
+}

20171023/structs-1.c

+#include <stdio.h>
+
+typedef struct
+{
+  char day, month;
+  int year;
+}
+date;
+
+void set_date (date *d)
+{
+  (*d).day = 23;
+  (*d).month = 10;
+  (*d).year = 2017;
+}
+
+int main (void)
+{
+  date today;
+  set_date (&today);
+  printf ("%d.%d.%d\n", today.day, today.month, today.year);
+  return 0;
+}

20171023/structs-2.c

+#include <stdio.h>
+
+typedef struct
+{
+  char day, month;
+  int year;
+}
+date;
+
+void set_date (date *d)
+{
+  d->day = 23;
+  d->month = 10;
+  d->year = 2017;
+}
+
+int main (void)
+{
+  date today;
+  set_date (&today);
+  printf ("%d.%d.%d\n", today.day, today.month, today.year);
+  return 0;
+}