Initial commit

kapitel11/simple-ls-ver1.c

@@ -0,0 +1,100 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <string.h>
+#include <dirent.h>
+#include <sys/stat.h>
+
+void printUsage(char *arg);
+
+int main(int argc, char **argv)
+{
+    unsigned int typ;
+    char opt[4] = { 0 };
+    
+    /* Skapa pekare och struct */
+    DIR           *d;
+    struct dirent *dir;
+    struct stat s;
+
+    /* Läs in aktuell katalog */
+    d = opendir(".");
+    /* Om 'd' INTE är sant (! = inte sant) */
+    if (!d)
+    {
+        printf("Kan inte läsa aktuell katalog\n");
+        return 1;
+    }
+    
+    /* Behandla arugment */
+    if (argc == 1)
+    {
+        strncpy(opt, "-a", 3);
+    }
+    else if (argc == 2)
+    {
+        strncpy(opt, argv[1], 3);
+    
+        /* Hjälptext */
+        if ( strcmp(opt, "-h") == 0 )
+            printUsage(argv[0]);
+
+        /* Visa endast filer */
+        else if ( strcmp(opt, "-f") == 0 )
+        {
+            typ = S_IFREG;
+        }
+
+        /* Visa endast kataloger */
+        else if ( strcmp(opt, "-d") == 0 )
+        {
+            typ = S_IFDIR;
+        }
+
+        /* Visa alla filer */
+        else if ( strcmp(opt, "-a") == 0 )
+        {
+            ;
+        }
+
+        /* Om vi angav ett felaktigt argument */
+        else
+        {
+            printUsage(argv[0]);
+            return 1;
+        }
+    }
+    /* Om vi angav fel antal argument */
+    else
+    {
+        printUsage(argv[0]);
+        return 1;
+    }
+
+    /* Skriv ut innehållet i katalogen */
+    while ((dir = readdir(d)) != NULL)
+    {
+        if ( strcmp(opt, "-a") == 0 )
+        {
+            printf("%s\n", dir->d_name);
+        }
+        else
+        {
+            stat(dir->d_name, &s);
+            /* Se kapitlet om 'Bitvisa operationer' */
+            if ((s.st_mode & S_IFMT) == typ)
+                printf("%s\n", dir->d_name);
+        }
+    }
+        
+    /* Stäng "d" och returnera noll */
+    closedir(d);
+    return 0;
+}
+
+void printUsage(char *arg)
+{
+    printf("Usage: %s [-a] [-f] [-d]\n"
+       "    -a to list all types (default)\n"
+       "    -f to list only files\n"
+       "    -d to list only directories\n", arg);
+}