This file concept supports the concept of a file pointer. In line 49, the printf statement prints the number of items successfully written to the file. After the write operation the file position indicator is moved to point at the next structure.
A write operation will write to the currently pointed-to structure. In this C programming tutorial we are going to talk about the use of binary files. The only disadvantage is the slowness that comes from disk access time. The return value of fwrite is then assigned to the chars variable.
Getting data using fseek If you have many records inside a file and need to access a record at a specific position, you need to loop through all the records before it to get the record.
You can change the contents of a structure anywhere in the file at any time. Generally, you move the pointer in sizeof struct rec increments to keep the pointer at record boundaries. We already know that on success fwrite returns the number of items written to the file.
Reading and writing to a binary file Functions fread and fwrite are used for reading from and writing to a file on the disk respectively in case of binary files.
Prev NEXT Binary files are very similar to arrays of structures, except the structures are in a disk file rather than in an array in memory. Only one block is requested.