File_Manipulation modified by Hugh Greene

Hugh Greene — Fri, 20 Jan 2023 12:15:44 -0000

The nice thing about emulating such a file manipulation library as Game
Maker's is that the method of identifying a file is an integer, like
everything else, which remains compliant with a 2-component variant data
type. Though many may prefer to keep track of the FILE pointer
themselves, this is a convenient method for those who don't wish to
concern themselves with such.

Classes

Achieving a unified storage class between text, binary, and ini file
manipulation is relatively simple due to the range of functions offered
by the original Game Maker library. The binary file
functions offered a method to clear
the file and start anew; this requires reopening the file by its
original name, which would need to be stored in that case. Text files
likewise require a string to store the last line read. Neither category
needs use of both.

That being the case, text and binary files are stored in a single
structure containing a FILE* member and a string member.

Text File Functions

Opens a text file for reading.
Opens a text file for writing.
Opens a text file for writing, but begins at the end of the file if
it exists.

Differences

For efficiency concerns, a slight modification was made to text file
behavior. While Game Maker does its reading in
file_text_read_string/real, and just sets variables in
file_text_readln and file_text_open, ENIGMA reads the first line in
the file as soon as a call to open is made. This saves a check in calls
to file_text_read_ string()/_real() down the road, but causes
file_text_open_read() itself to take slightly longer. Typical use of
these functions will introduce no visible difference, save minute
speedup.

Binary File Functions

opens the file fname as a binary file with the given mode, which is
an integer from the table below.

Name	Value	Description
Read	0	Opens the file for reading.
Write	1	Opens the file for writing.
Both	2	Opens the file with read and write permissions.

C/C++ File Functions