From 091b9cba71a77dcfb06a6ceb4d6f1d6aa40633e2 Mon Sep 17 00:00:00 2001
From: Peter Gerwinski <peter.gerwinski@hs-bochum.de>
Date: Fri, 20 Oct 2023 00:04:50 +0200
Subject: [PATCH] Beispiele 19.10.2023
---
20231019/arrays-05a.c | 9 +++++++++
20231019/arrays-05b.c | 9 +++++++++
20231019/arrays-05c.c | 15 ++++++++++++++
20231019/fhello.txt | 1 +
20231019/files-01.c | 9 +++++++++
20231019/files-02.c | 12 ++++++++++++
20231019/files-03.c | 14 +++++++++++++
20231019/files-04.c | 14 +++++++++++++
20231019/files-05.c | 15 ++++++++++++++
20231019/files-06.c | 19 ++++++++++++++++++
20231019/files-07.c | 20 +++++++++++++++++++
20231019/files-07.txt | 40 ++++++++++++++++++++++++++++++++++++++
20231019/files-08.c | 13 +++++++++++++
20231019/params-00.c | 7 +++++++
20231019/params-01.c | 9 +++++++++
20231019/params-02.c | 9 +++++++++
20231019/params-03.c | 9 +++++++++
20231019/side-effects-16.c | 12 ++++++++++++
20231019/side-effects-17.c | 12 ++++++++++++
20231019/side-effects-18.c | 13 +++++++++++++
20231019/strings-01.c | 9 +++++++++
20231019/strings-02.c | 9 +++++++++
20231019/strings-03.c | 9 +++++++++
20231019/strings-04.c | 9 +++++++++
20231019/strings-05.c | 10 ++++++++++
20231019/strings-06.c | 21 ++++++++++++++++++++
20231019/strings-07.c | 21 ++++++++++++++++++++
20231019/strings-08.c | 19 ++++++++++++++++++
20231019/structs-01.c | 15 ++++++++++++++
20231019/structs-02.c | 23 ++++++++++++++++++++++
20231019/structs-03.c | 23 ++++++++++++++++++++++
20231019/variables-01.c | 8 ++++++++
20231019/variables-02.c | 9 +++++++++
33 files changed, 446 insertions(+)
create mode 100644 20231019/arrays-05a.c
create mode 100644 20231019/arrays-05b.c
create mode 100644 20231019/arrays-05c.c
create mode 100644 20231019/fhello.txt
create mode 100644 20231019/files-01.c
create mode 100644 20231019/files-02.c
create mode 100644 20231019/files-03.c
create mode 100644 20231019/files-04.c
create mode 100644 20231019/files-05.c
create mode 100644 20231019/files-06.c
create mode 100644 20231019/files-07.c
create mode 100644 20231019/files-07.txt
create mode 100644 20231019/files-08.c
create mode 100644 20231019/params-00.c
create mode 100644 20231019/params-01.c
create mode 100644 20231019/params-02.c
create mode 100644 20231019/params-03.c
create mode 100644 20231019/side-effects-16.c
create mode 100644 20231019/side-effects-17.c
create mode 100644 20231019/side-effects-18.c
create mode 100644 20231019/strings-01.c
create mode 100644 20231019/strings-02.c
create mode 100644 20231019/strings-03.c
create mode 100644 20231019/strings-04.c
create mode 100644 20231019/strings-05.c
create mode 100644 20231019/strings-06.c
create mode 100644 20231019/strings-07.c
create mode 100644 20231019/strings-08.c
create mode 100644 20231019/structs-01.c
create mode 100644 20231019/structs-02.c
create mode 100644 20231019/structs-03.c
create mode 100644 20231019/variables-01.c
create mode 100644 20231019/variables-02.c
diff --git a/20231019/arrays-05a.c b/20231019/arrays-05a.c
new file mode 100644
index 0000000..8260614
--- /dev/null
+++ b/20231019/arrays-05a.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ int prime[6] = { 2, 3, 5, 0, 7, 11 };
+ for (int *p = prime; *p; p++)
+ printf ("%d\n", *p);
+ return 0;
+}
diff --git a/20231019/arrays-05b.c b/20231019/arrays-05b.c
new file mode 100644
index 0000000..77e4c7c
--- /dev/null
+++ b/20231019/arrays-05b.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ int prime[5] = { 2, 3, 5, 7, 11 };
+ for (int *p = prime; *p; p++)
+ printf ("%d\n", *p);
+ return 0;
+}
diff --git a/20231019/arrays-05c.c b/20231019/arrays-05c.c
new file mode 100644
index 0000000..8ba1334
--- /dev/null
+++ b/20231019/arrays-05c.c
@@ -0,0 +1,15 @@
+
+#include <stdio.h>
+
+int main (void)
+{
+ int pflll[8] = { 1, 2, 3, 4, 5, 6, 7, 8 };
+ int prime[8] = { 2, 3, 5, 7, 11, 13, 17, 19 };
+ printf ("prime:\n");
+ for (int *p = prime; *p; p++)
+ printf ("%d\n", *p);
+ printf ("pflll:\n");
+ for (int *q = pflll; *q; q++)
+ printf ("%d\n", *q);
+ return 0;
+}
diff --git a/20231019/fhello.txt b/20231019/fhello.txt
new file mode 100644
index 0000000..af5626b
--- /dev/null
+++ b/20231019/fhello.txt
@@ -0,0 +1 @@
+Hello, world!
diff --git a/20231019/files-01.c b/20231019/files-01.c
new file mode 100644
index 0000000..6548d9c
--- /dev/null
+++ b/20231019/files-01.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ return 0;
+}
diff --git a/20231019/files-02.c b/20231019/files-02.c
new file mode 100644
index 0000000..6bd3fc9
--- /dev/null
+++ b/20231019/files-02.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ if (f)
+ {
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ }
+ return 0;
+}
diff --git a/20231019/files-03.c b/20231019/files-03.c
new file mode 100644
index 0000000..dad47ea
--- /dev/null
+++ b/20231019/files-03.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ if (f)
+ {
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ }
+ else
+ printf ("Fehlermeld!\n");
+ return 0;
+}
diff --git a/20231019/files-04.c b/20231019/files-04.c
new file mode 100644
index 0000000..31e6480
--- /dev/null
+++ b/20231019/files-04.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ if (f)
+ {
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ }
+ else
+ fprintf (stderr, "Fehlermeld!\n");
+ return 0;
+}
diff --git a/20231019/files-05.c b/20231019/files-05.c
new file mode 100644
index 0000000..46b01f8
--- /dev/null
+++ b/20231019/files-05.c
@@ -0,0 +1,15 @@
+#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, "Fehler Nr. %d\n", errno);
+ return 0;
+}
diff --git a/20231019/files-06.c b/20231019/files-06.c
new file mode 100644
index 0000000..ec3e8a7
--- /dev/null
+++ b/20231019/files-06.c
@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ if (f)
+ {
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ }
+ else
+ {
+ char *msg = strerror (errno);
+ fprintf (stderr, "Fehler: %s\n", msg);
+ }
+ return 0;
+}
diff --git a/20231019/files-07.c b/20231019/files-07.c
new file mode 100644
index 0000000..607ffbd
--- /dev/null
+++ b/20231019/files-07.c
@@ -0,0 +1,20 @@
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ if (f)
+ {
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ return 0;
+ }
+ else
+ {
+ char *msg = strerror (errno);
+ fprintf (stderr, "Fehler: %s\n", msg);
+ return errno;
+ }
+}
diff --git a/20231019/files-07.txt b/20231019/files-07.txt
new file mode 100644
index 0000000..b8f268c
--- /dev/null
+++ b/20231019/files-07.txt
@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+int main (void)
+{
+ FILE *f = fopen ("fhello.txt", "w");
+ if (f)
+ {
+ fprintf (f, "Hello, world!\n");
+ fclose (f);
+ return 0;
+ }
+ else
+ {
+ char *msg = strerror (errno);
+ fprintf (stderr, "Fehler: %s\n", msg);
+ return errno;
+ }
+}
+cassini/home/peter/bo/2023ws/hp/20231019> gcc -Wall -O files-07.c -o files-07
+cassini/home/peter/bo/2023ws/hp/20231019> ./files-07
+Fehler: Permission denied
+cassini/home/peter/bo/2023ws/hp/20231019> echo $?
+13
+cassini/home/peter/bo/2023ws/hp/20231019> rm fhello.txt
+rm: reguläre Datei (schreibgeschützt) 'fhello.txt' entfernen? y
+cassini/home/peter/bo/2023ws/hp/20231019> ./files-07
+cassini/home/peter/bo/2023ws/hp/20231019> echo $?
+0
+cassini/home/peter/bo/2023ws/hp/20231019> ls -l fhello.txt
+-rw-r--r-- 1 peter peter 14 19. Okt 15:56 fhello.txt
+cassini/home/peter/bo/2023ws/hp/20231019> chmod -w fhello.txt
+cassini/home/peter/bo/2023ws/hp/20231019> ls -l fhello.txt
+-r--r--r-- 1 peter peter 14 19. Okt 15:56 fhello.txt
+cassini/home/peter/bo/2023ws/hp/20231019> ./files-07
+Fehler: Permission denied
+cassini/home/peter/bo/2023ws/hp/20231019> echo $?
+13
+cassini/home/peter/bo/2023ws/hp/20231019>
diff --git a/20231019/files-08.c b/20231019/files-08.c
new file mode 100644
index 0000000..383cb35
--- /dev/null
+++ b/20231019/files-08.c
@@ -0,0 +1,13 @@
+#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;
+}
diff --git a/20231019/params-00.c b/20231019/params-00.c
new file mode 100644
index 0000000..c1e45bf
--- /dev/null
+++ b/20231019/params-00.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+int main (int argc, char **argv)
+{
+ printf ("%s\n", *argv);
+ return 0;
+}
diff --git a/20231019/params-01.c b/20231019/params-01.c
new file mode 100644
index 0000000..e6e64ba
--- /dev/null
+++ b/20231019/params-01.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (int argc, char **argv)
+{
+ printf ("argc = %d\n", argc);
+ for (int i = 0; i < argc; i++)
+ printf ("argv[%d] = \"%s\"\n", i, argv[i]);
+ return 0;
+}
diff --git a/20231019/params-02.c b/20231019/params-02.c
new file mode 100644
index 0000000..3a52b55
--- /dev/null
+++ b/20231019/params-02.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (int argc, char *argv[])
+{
+ printf ("argc = %d\n", argc);
+ for (int i = 0; i < argc; i++)
+ printf ("argv[%d] = \"%s\"\n", i, argv[i]);
+ return 0;
+}
diff --git a/20231019/params-03.c b/20231019/params-03.c
new file mode 100644
index 0000000..0e932b3
--- /dev/null
+++ b/20231019/params-03.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (int argc, char **argv)
+{
+ printf ("argc = %d\n", argc);
+ for (int i = 0; *argv; i++, argv++)
+ printf ("argv[%d] = \"%s\"\n", i, *argv);
+ return 0;
+}
diff --git a/20231019/side-effects-16.c b/20231019/side-effects-16.c
new file mode 100644
index 0000000..09d985f
--- /dev/null
+++ b/20231019/side-effects-16.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+void add_verbose (int a, int b)
+{
+ printf ("%d + %d = %d\n", a, b, a + b);
+}
+
+int main (void)
+{
+ add_verbose (3, 7);
+ return 0;
+}
diff --git a/20231019/side-effects-17.c b/20231019/side-effects-17.c
new file mode 100644
index 0000000..11d4d45
--- /dev/null
+++ b/20231019/side-effects-17.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int add_verbose (int a, int b)
+{
+ printf ("%d + %d = %d\n", a, b, a + b);
+}
+
+int main (void)
+{
+ add_verbose (3, 7);
+ return 0;
+}
diff --git a/20231019/side-effects-18.c b/20231019/side-effects-18.c
new file mode 100644
index 0000000..5b4322f
--- /dev/null
+++ b/20231019/side-effects-18.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int add_verbose (int a, int b)
+{
+ printf ("%d + %d = %d\n", a, b, a + b);
+ return 42;
+}
+
+int main (void)
+{
+ add_verbose (3, 7);
+ return 0;
+}
diff --git a/20231019/strings-01.c b/20231019/strings-01.c
new file mode 100644
index 0000000..81bc3cd
--- /dev/null
+++ b/20231019/strings-01.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ char hello[] = "Hello, world!\n";
+ for (char *p = hello; *p; p++)
+ printf ("%d", *p);
+ return 0;
+}
diff --git a/20231019/strings-02.c b/20231019/strings-02.c
new file mode 100644
index 0000000..f1332bc
--- /dev/null
+++ b/20231019/strings-02.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ char hello[] = "Hello\x00, world!\n";
+ for (char *p = hello; *p; p++)
+ printf ("%d", *p);
+ return 0;
+}
diff --git a/20231019/strings-03.c b/20231019/strings-03.c
new file mode 100644
index 0000000..4df3297
--- /dev/null
+++ b/20231019/strings-03.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ char hello[] = "Hello, world!\n";
+ for (char *p = hello; *p; p++)
+ printf ("%c", *p);
+ return 0;
+}
diff --git a/20231019/strings-04.c b/20231019/strings-04.c
new file mode 100644
index 0000000..5c36db9
--- /dev/null
+++ b/20231019/strings-04.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int main (void)
+{
+ char hello[] = { 72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33, 10, 0 };
+ for (char *p = hello; *p; p++)
+ printf ("%c", *p);
+ return 0;
+}
diff --git a/20231019/strings-05.c b/20231019/strings-05.c
new file mode 100644
index 0000000..5c9a710
--- /dev/null
+++ b/20231019/strings-05.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main (void)
+{
+ char hello[] = { 72, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100, 33, 10, 0 };
+ for (char *p = hello; *p; p++)
+ printf (" %02x", *p);
+ printf ("\n");
+ return 0;
+}
diff --git a/20231019/strings-06.c b/20231019/strings-06.c
new file mode 100644
index 0000000..268aa0d
--- /dev/null
+++ b/20231019/strings-06.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <string.h>
+
+int main (void)
+{
+ char hello[] = "Hello, world!\n";
+
+ printf ("%s\n", hello);
+ printf ("%zd\n", strlen (hello));
+
+ return 0;
+
+ printf ("%s\n", hello + 7);
+ printf ("%zd\n", strlen (hello + 7));
+
+ hello[5] = 0;
+ printf ("%s\n", hello);
+ printf ("%zd\n", strlen (hello));
+
+ return 0;
+}
diff --git a/20231019/strings-07.c b/20231019/strings-07.c
new file mode 100644
index 0000000..d9bbb48
--- /dev/null
+++ b/20231019/strings-07.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <string.h>
+
+int main (void)
+{
+ char hello[] = "Hello, world!\n";
+
+ printf ("%s\n", hello);
+ printf ("%zd\n", strlen (hello));
+
+ printf ("%s\n", hello + 7);
+ printf ("%zd\n", strlen (hello + 7));
+
+ return 0;
+
+ hello[5] = 0;
+ printf ("%s\n", hello);
+ printf ("%zd\n", strlen (hello));
+
+ return 0;
+}
diff --git a/20231019/strings-08.c b/20231019/strings-08.c
new file mode 100644
index 0000000..dd05111
--- /dev/null
+++ b/20231019/strings-08.c
@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <string.h>
+
+int main (void)
+{
+ char hello[] = "Hello, world!\n";
+
+ printf ("%s\n", hello);
+ printf ("%zd\n", strlen (hello));
+
+ printf ("%s\n", hello + 7);
+ printf ("%zd\n", strlen (hello + 7));
+
+ hello[5] = 0;
+ printf ("%s\n", hello);
+ printf ("%zd\n", strlen (hello));
+
+ return 0;
+}
diff --git a/20231019/structs-01.c b/20231019/structs-01.c
new file mode 100644
index 0000000..4e01487
--- /dev/null
+++ b/20231019/structs-01.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+typedef struct
+{
+ char day, month;
+ int year;
+}
+date;
+
+int main (void)
+{
+ date today = { 19, 10, 2023 };
+ printf ("%d.%d.%d\n", today.day, today.month, today.year);
+ return 0;
+}
diff --git a/20231019/structs-02.c b/20231019/structs-02.c
new file mode 100644
index 0000000..00e0bfe
--- /dev/null
+++ b/20231019/structs-02.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+typedef struct
+{
+ char day, month;
+ int year;
+}
+date;
+
+void set_date (date *d)
+{
+ (*d).day = 17;
+ (*d).month = 10;
+ (*d).year = 2022;
+}
+
+int main (void)
+{
+ date today;
+ set_date (&today);
+ printf ("%d.%d.%d\n", today.day, today.month, today.year);
+ return 0;
+}
diff --git a/20231019/structs-03.c b/20231019/structs-03.c
new file mode 100644
index 0000000..7decf4b
--- /dev/null
+++ b/20231019/structs-03.c
@@ -0,0 +1,23 @@
+#include <stdio.h>
+
+typedef struct
+{
+ char day, month;
+ int year;
+}
+date;
+
+void set_date (date *d)
+{
+ d->day = 17;
+ d->month = 10;
+ d->year = 2022;
+}
+
+int main (void)
+{
+ date today;
+ set_date (&today);
+ printf ("%d.%d.%d\n", today.day, today.month, today.year);
+ return 0;
+}
diff --git a/20231019/variables-01.c b/20231019/variables-01.c
new file mode 100644
index 0000000..fe8f18a
--- /dev/null
+++ b/20231019/variables-01.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+ int a;
+ printf ("a = %d\n", a);
+ return 0;
+}
diff --git a/20231019/variables-02.c b/20231019/variables-02.c
new file mode 100644
index 0000000..dd0c808
--- /dev/null
+++ b/20231019/variables-02.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+int a;
+
+int main (void)
+{
+ printf ("a = %d\n", a);
+ return 0;
+}
--
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