"Finishd all of the functions "

Assignmnt-02/starter/sdbsc.c

@@ -204,7 +204,7 @@ int del_student(int fd, int id)
     myoffset = id * STUDENT_RECORD_SIZE;
 
     off_t lseek_result = lseek(fd, myoffset, SEEK_SET);
-    if (lseek_result) {
+    if (lseek_result < 1) {
         printf(M_ERR_DB_READ);
         return ERR_DB_FILE;
     }
@@ -246,9 +246,41 @@ int del_student(int fd, int id)
  */
 int count_db_records(int fd)
 {
-    // TODO
-    printf(M_NOT_IMPL);
-    return NOT_IMPLEMENTED_YET;
+    int count = 0;
+    student_t temp;
+    ssize_t bytes;
+    
+    off_t lseek_result = lseek(fd, 0, SEEK_SET );
+
+    if (lseek_result < 0 ) {
+        printf(M_ERR_DB_READ);
+        return ERR_DB_FILE;
+    }
+
+
+    while (1)
+    {
+        bytes = read(fd, &temp, sizeof(student_t) );
+        if (bytes == -1) {
+            return ERR_DB_FILE;
+        } else if (bytes == 0) {
+            break;
+        } else if (bytes != STUDENT_RECORD_SIZE) {
+            return ERR_DB_FILE;
+        }
+        
+        if (memcmp(&temp, &EMPTY_STUDENT_RECORD, STUDENT_RECORD_SIZE) != 0) {
+            count++;
+        }
+    }
+
+    if (count == 0){
+        printf(M_DB_EMPTY);
+    } else {
+        printf(M_DB_RECORD_CNT, count);
+    }
+
+    return count;
 }
 
 /*
@@ -286,11 +318,53 @@ int count_db_records(int fd)
  */
 int print_db(int fd)
 {
-    // TODO
-    printf(M_NOT_IMPL);
-    return NOT_IMPLEMENTED_YET;
+    student_t temp;
+    ssize_t bytes;
+    int first_record = 1;
+    
+    off_t lseek_result = lseek(fd, 0, SEEK_SET );
+
+    if (lseek_result < 0 ) {
+        printf(M_ERR_DB_READ);
+        return ERR_DB_FILE;
     }
 
+
+    while (1)
+    {
+        bytes = read(fd, &temp, sizeof(student_t) );
+        if (bytes == -1) {
+            printf(M_ERR_DB_READ);
+            return ERR_DB_FILE;
+        } else if (bytes == 0) {
+            break;
+        } else if (bytes != STUDENT_RECORD_SIZE) {
+            printf(M_ERR_DB_READ);
+            return ERR_DB_FILE;
+        }
+        
+        if (memcmp(&temp, &EMPTY_STUDENT_RECORD, STUDENT_RECORD_SIZE) == 0) {
+            continue;
+        }
+
+        if (first_record) {
+            printf(STUDENT_PRINT_HDR_STRING, "ID", "FIRST NAME", "LAST_NAME", "GPA");
+            first_record = 0;
+        }
+
+        float gpa = temp.gpa / 100.0;
+        printf(STUDENT_PRINT_FMT_STRING, temp.id, temp.fname, temp.lname, gpa);
+    }
+
+    if (first_record) {
+        printf(M_DB_EMPTY) ;
+    }
+
+    return NO_ERROR;
+
+}
+
+
 /*
  *  print_student
  *      *s:   a pointer to a student_t structure that should
@@ -321,8 +395,17 @@ int print_db(int fd)
  */
 void print_student(student_t *s)
 {
-    // TODO
-    printf(M_NOT_IMPL);
+    if (s == NULL || s-> id == 0 ) {
+        printf(M_ERR_STD_PRINT);
+        return;
+    }
+
+    printf(STUDENT_PRINT_HDR_STRING, "ID", "FIRST NAME", "LAST_NAME", "GPA");
+
+    float gpa = s->gpa / 100.0;
+
+    printf(STUDENT_PRINT_FMT_STRING, s->id, s->fname, student.lname, calculated_gpa_from_s);
+
 }
 
 /*