Initial commit

kapitel13/filinfo-portabel.c

@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#if __STDC_VERSION__ >= 199901L
+#define C99
+#include <inttypes.h>
+#endif
+
+int main(int argc, char *argv[])
+{
+    struct stat fileinfo;
+    if (argc != 2)
+    {
+        fprintf(stderr, "Usage: %s path/to/file\n", argv[0]);
+        return 1;
+    }
+
+    stat(argv[1], &fileinfo);
+
+    #ifdef C99
+    printf("C99 (or newer)\n");
+    printf("Inode number: %ju\n",
+           (uintmax_t)fileinfo.st_ino);
+    printf("Size in bytes: %jd (%.2f kilobytes)\n",
+           (intmax_t)fileinfo.st_size,
+           (double)fileinfo.st_size / 1024);
+    #else
+    printf("C89\n");
+    printf("Inode number: %lu\n", (unsigned long int)fileinfo.st_ino);
+    printf("Size in bytes: %lu (%.2f kilobytes)\n",
+           (unsigned long int)fileinfo.st_size,
+           (float)fileinfo.st_size / 1024);
+    #endif
+    printf("User-ID: %d\n", fileinfo.st_uid);
+    printf("Group-ID: %d\n", fileinfo.st_gid);
+
+    return 0;
+}

kapitel13/filinfo.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+int main(int argc, char *argv[])
+{
+    struct stat fileinfo;
+    if (argc != 2)
+    {
+        fprintf(stderr, "Usage: %s path/to/file\n", argv[0]);
+        return 1;
+    }
+
+    stat(argv[1], &fileinfo);
+
+    printf("Inode number: %lu\n", (unsigned long int)fileinfo.st_ino);
+    printf("Size in bytes: %lu (%.2f kilobytes)\n",
+           (unsigned long int)fileinfo.st_size,
+           (float)fileinfo.st_size / 1024);
+    printf("User-ID: %d\n", fileinfo.st_uid);
+    printf("Group-ID: %d\n", fileinfo.st_gid);
+
+    return 0;
+}

kapitel13/mychown-felhantering-ex1.c

@@ -0,0 +1,42 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+int main(int argc, char *argv[])
+{
+    uid_t uid;
+    gid_t gid;
+
+    if (argc != 4)
+    {
+        fprintf(stderr, "Usage: %s <file> <uid> <gid>\n", argv[0]);
+        return 1;
+    }
+
+    uid = (uid_t)atoi(argv[2]);
+    gid = (gid_t)atoi(argv[3]);
+    
+    if (chown(argv[1], uid, gid) == -1)
+    {
+        switch (errno)
+        {
+        case EPERM:
+            fprintf(stderr, "Operation not permitted\n");
+            break;
+        case ENOENT:
+            fprintf(stderr, "No such file or directory\n");
+            break;
+        case ENAMETOOLONG:
+            fprintf(stderr, "Filename too long\n");
+            break;
+        default:
+            fprintf(stderr, "Unknown error\n");
+            break;
+        }
+        return 1;
+    }
+
+    return 0;
+}

kapitel13/mychown-felhantering-ex2.c

@@ -0,0 +1,30 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+int main(int argc, char *argv[])
+{
+    uid_t uid;
+    gid_t gid;
+
+    if (argc != 4)
+    {
+        fprintf(stderr, "Usage: %s <file> <uid> <gid>\n", argv[0]);
+        return 1;
+    }
+
+    uid = (uid_t)atoi(argv[2]);
+    gid = (gid_t)atoi(argv[3]);
+    
+    if (chown(argv[1], uid, gid) == -1)
+    {
+        printf("%i\n", errno); /* Visar vad errno innehåller */
+        printf("%s\n", strerror(errno)); /* Meddelandet i klartext */
+        return 1;
+    }
+
+    return 0;
+}

kapitel13/mychown-felhantering-ex3.c

@@ -0,0 +1,27 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+
+int main(int argc, char *argv[])
+{
+    uid_t uid;
+    gid_t gid;
+
+    if (argc != 4)
+    {
+        fprintf(stderr, "Usage: %s <file> <uid> <gid>\n", argv[0]);
+        return 1;
+    }
+
+    uid = (uid_t)atoi(argv[2]);
+    gid = (gid_t)atoi(argv[3]);
+    
+    if (chown(argv[1], uid, gid) == -1)
+    {
+        perror("chown");
+        return 1;
+    }
+    return 0;
+}

kapitel13/mychown.c

@@ -0,0 +1,27 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[])
+{
+    uid_t uid;
+    gid_t gid;
+
+    if (argc != 4)
+    {
+        fprintf(stderr, "Usage: %s <file> <uid> <gid>\n", argv[0]);
+        return 1;
+    }
+
+    uid = (uid_t)atoi(argv[2]);
+    gid = (gid_t)atoi(argv[3]);
+    
+    if (chown(argv[1], uid, gid) == -1)
+    {
+        fprintf(stderr, "Could not change UID or GID\n");
+        return 1;
+    }
+
+    return 0;
+}

kapitel13/mytouch.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+int main(int argc, char *argv[])
+{
+    if (argc != 2)
+    {
+        fprintf(stderr, "Usage: %s <file>\n", argv[0]);
+        return 1;
+    }
+    /* Rättigheterna nedan blir 644, Read/Write user, 
+       Read group, Read others */
+    creat(argv[1], S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+    if (errno != 0)
+    {
+        perror("creat");
+        return 1;
+    }
+    return 0;
+}

kapitel13/write-ex1.c

@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main(void)
+{
+    write(1, "Hejsan\n", 7);
+    return 0;
+}

kapitel13/write-ex2.c

@@ -0,0 +1,8 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main(void)
+{
+    write(STDOUT_FILENO, "Hejsan\n", 7);
+    return 0;
+}