File system syscalls

• Note: More read and write fs instructions will be added in the future for ease of use (Read all, write X bytecount)

• Another note: The f macro will be used a lot here, so learn how it works first!

Syscalls for interacting with ComputerCraft’s file system. Like CC’s file system, all paths are absolute, which is why many syslib functions include a “currentDir” parameter for ease of use.

Opened file handles are stored in a “file slot” table. To interact with most of the functions regarding file manipulation you will need to know the file slot of the file you have opened.

OPEN : 2 chars for mode, null terminated string for filename.

Returns a file slot number. You can open up to 255 files at once.

The modes are made out of the operation, ‘a’, ‘w’, ‘r’, and if it’s in text more or not ‘t’, ‘b’ (Replicates CraftOS’ FS)

//Example code with syslib.h
int file = fsopen(currentDir, filename, 'w', 'b');

//Example code with only lib.h
f(syssend, "OPEN");
write_char('w');
write_char('b');
syssend(filename);
sysend();
int file = read_char();

CLOS : 1 char for the file slot.

Closes file slot, freeing it for future use, saving all changes.

//Example code with syslib.h
fsclose(fileslot);

//Example code with only lib.h
f(syssend, "CLOS");
write_char(fileslot);

REAB : 1 char for the file slot, 1 short for how many bytes to read.

Read bytes from an open file slot. (Current C implementation doesn’t support reading more than 255 chars at once, but the syscall supports reading up to 65536 bytes at once)

//Example code with syslib.h
fsclose(fileslot);

//Example code with only lib.h
int out[size];
f(syssend, "REAB");
write_char(fileslot);
write_short(size);
sysread(out, size);

SIZE : 1 null terminated string for the filename.

Get the size of a file as a short.

//Example code with syslib.h
int size = fssize(currentDir, filename);

//Example code with only lib.h
f(syssend, "SIZE");
syssend(filename);
sysend();
int size = read_short();

LSSZ : 1 null terminated string for the filename.

Get the amount of files in a directory as a char.

//Example code with syslib.h
int count = fslist(name, currentDir);

//Example code with only lib.h
f(syssend, "LSSZ");
syssend(name);
sysend();
int count = read_char();

GTLS : 1 char for the index.

Index the current directory. Designed to be used with LSSZ to list a directory’s files. Returns: null terminated string with filetype + filename examples: Fim_a_file.txt - Dim_a_directory

//Example code with syslib.h
fsgetindex(currentDir, x, filename, DIR_SIZE);

//Example code with only lib.h
f(syssend, "GTLS");
write_char(index+1); //Because, Lua
syssend(currentDir);
sysend();
sysread(out, size);

EXEC : 1 null terminated string for filename.

Executes given filename with the bfk.lua Brainfuck interpreter the OS uses.

//Example code with syslib.h
execInDir(currentDir, command);

//Example code with only lib.h
f(syssend, "EXEC");
syssend(filename);
sysend();

MDIR : 1 null terminated string for path name.

Creates the given path.

//Example code with syslib.h
makeDir(currentDir, dirName);

//Example code with only lib.h
f(syssend, "MDIR");
syssend(path);
sysend();

DELF : 1 null terminated string for path name.

Deletes the given path.

//Example code with syslib.h
deletePath(currentDir, dirName);

//Example code with only lib.h
f(syssend, "DELF");
syssend(path);
sysend();

WRTE : 1 char for fileslot, null terminated string for what to write

Writes a string to the given fileslot

//Example code with syslib.h
fswrite(file, text);

//Example code with only lib.h
f(syssend, "WRTE");
write_char(fileslot);
syssend(string);
sysend();

EDIR : null terminated string for path

Check if path exists and if it’s a directory, returns either 0 or 1

//Example code with syslib.h
bool exists = fsexists(name, currentDir);

//Example code with only lib.h
f(syssend, "EDIR");
syssend(path);
sysend();
bool exists = (read_char() == 1);

EFIL : null terminated string for path

Check if path exists and if it’s a file, returns either 0 or 1

//Example code with syslib.h
bool exists = fsexistsfile(name, currentDir);

//Example code with only lib.h
f(syssend, "EFIL");
syssend(path);
sysend();
bool exists = (read_char() == 1);

FCPY : 1 char, size of the source filename, string for source filename, null terminated string for the destination filename.

Copies a file from a source path to a destination path

//Example code with syslib.h
fscopy(currentDir, fileA, fileB);

//Example code with only lib.h
f(syssend, "FCPY");
int i=0;
while (fileA[i]!=0) {
    i = i + 1;
}
write_char(i);
syssend(currentDir);
syssend(fileA);
syssend(currentDir);
syssend(fileB);
sysend();

FMOV : 1 char, size of the source filename, string for source filename, null terminated string for the destination filename.

Moves a file from a source path to a destination path

//Example code with syslib.h
fsmove(currentDir, fileA, fileB);

//Example code with only lib.h
f(syssend, "FMOV");
int i=0;
while (fileA[i]!=0) {
    i = i + 1;
}
write_char(i);
syssend(currentDir);
syssend(fileA);
syssend(currentDir);
syssend(fileB);
sysend();