before lec 5

section01/Lec05/bug.c

+#include <stdio.h>
+#include <string.h>
+
+int main(void)
+{
+    char str[80] = "csci206";
+    int i = 42;
+    int *pi = &i;
+
+    printf("step1\n"); 
+    strcat(str, " is cool");
+
+    printf("step2"); fflush(stdout);
+    pi[5] = 0;
+
+    printf("\n%s (%d)\n", str, i);
+}

section01/Lec05/file_cstd.c

+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char* argv[])
+{
+    FILE *file;
+
+    if (argc <= 1){
+        printf("please speficy filename on the command line.\n");
+        exit(1);
+    } else {
+        printf ("writing to %s\n", argv[1]);
+    }
+
+    file = fopen(argv[1], "w");
+    
+    fprintf(file, "Hello file world!\n");
+
+    fclose(file);
+}

section01/Lec05/file_syscall.c

+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[])
+{
+    if (argc <= 1){
+        printf("Please supply a filename on the command line.\n");
+        exit(1);
+    } else {
+        printf("writing to %s\n", argv[1]);
+    }
+
+    char *message = "Hello file world!\n";
+    int file_handle = open(argv[1], 
+                           O_WRONLY | O_CREAT, 
+                           S_IRWXU | S_IRWXG | S_IROTH);
+    
+    write (file_handle, message, strlen(message));
+    close (file_handle);
+
+    return 0;
+}