c version of file operations

section_1/funcs/fops.c

@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+
+int main(int argc, char **argv) {
+    char * fname = "test.txt";
+    char * p_legend = NULL;
+    int fd = open(fname, O_RDWR | O_CREAT, 00600);
+    int retval = 0;
+    off_t seek_return;
+    char buffer[80];
+
+    if (fd < 0) {
+        p_legend = fname;
+        goto out;
+    } else {
+        printf("Flags used to open file: %o\n", O_RDWR | O_CREAT);
+        for (int counter = 0; counter < 10; counter++) {
+            if (write(fd, "data\n", 5) != 5) {
+                p_legend = "On writing";
+				goto out;
+			}
+        }
+
+        if (seek_return = lseek(fd, 0, SEEK_SET) != 0) {
+            p_legend = "On seeking";
+            goto out;
+        }
+        
+        for (int counter = 0; counter < 10; counter++) {
+            memset(buffer, 0, 80);
+            if (read(fd, buffer, 5) != 5) {
+                p_legend = "On reading";
+                goto out;
+            }
+            printf("%d %s", counter, buffer);
+        }
+
+out:    if (fd >= 0) {
+            close(fd);
+            if (unlink(fname)) {
+                p_legend = "On unlinking";
+            }
+        }
+
+        if (p_legend != NULL) {
+            perror(p_legend);
+            retval = 1;
+        }
+	}
+    return retval;
+}