14- RPGLE - Using C procedures to manipulate IFS files

To manipulate IFS files in RPGLE using C procedures, you can utilize C APIs like open(), read(), write(), and close(). These APIs allow you to perform operations such as creating, opening, reading, writing, and closing IFS stream files. Here’s a brief overview:

1. Creating and Opening Files: Use the open() API to create or open an IFS file. It returns a file descriptor that you can use for subsequent operations. You can specify flags like O_RDONLY (read-only), O_WRONLY (write-only), or O_RDWR (read and write).
2. Reading Files: The read() API reads data from an IFS file into a buffer. You need to specify the file descriptor, buffer, and the number of bytes to read.
3. Writing Files: The write() API writes data from a buffer to an IFS file. Similar to read(), you provide the file descriptor, buffer, and the number of bytes to write.
4. Closing Files: Always use the close() API to close the file descriptor after completing your operations.

These APIs are typically part of the service program QP0LLIB1 in the QSYS library. You can prototype these APIs in your RPGLE program to call them effectively.