Module 06 - File Management
Lesson 01 - Reading Files
Once a file has been opened in read mode (or one of the random modes), each line of the file can be read one at a time with FREAD. You must again send the filepath of the file you want to read as an argument.
FREAD will read one line of the file each time it is called. The end of line characters (CR and LF) will be omitted.
If FREAD is successful, the return will be either the string of text for that line of the file, or -1 if it has reached the end of the file. If it fails, it will return an empty string.
OnReadFile
{
_file = "examplefiles/readexample.txt"
_hellos_found = 0
if FOPEN(_file,"r") == 1
{
for _f = FREAD(_file); _f != -1; _f = FREAD(_file)
{
if "Hello, world!" _in_ _f
{
_hellos_found++
}
}
void FCLOSE(_file)
}
"Number of ""Hello, world!""s found in file: %(_hellos_found)"
}
Click to run the above code in the Ghost Guides companion ghost.
The above function will output Number of "Hello, world!"s found in file: , followed by the number of lines containing the string “Hello, world!” in the example file.
Further Context
The loop in the above function is a way to read every single line in a file. It initializes the variable _f to the first line of the file, and each time the loop repeats, it reads a new line, until FREAD returns -1 which causes the loop to stop.
You don’t have to use FREAD in a loop! If you’re expecting a file with a very particular format, where you know what data will be on each line, you can just write the exact number of FREAD commands you need.
Here’s another example that reads a playlist file, and copies the playlist into an array.
OnLoadPlaylist
{
PlaylistArray = IARRAY
_file = "../../playlists/myplaylist.m3u"
void FOPEN(_file,"r")
for _f = FREAD(_file); _f != -1; _f = FREAD(_file)
{
PlaylistArray ,= _f
}
void FCLOSE(_file)
}