file.hpp File Reference

Functions for interacting with the calculator's file system. More...

#include <stdint.h>

Include dependency graph for file.hpp:

Go to the source code of this file.

Classes
struct	stat
struct	findInfo

Functions
constexpr uint16_t	statDateYear (uint16_t date)
constexpr uint16_t	statDateMonth (uint16_t date)
constexpr uint16_t	statDateDay (uint16_t date)
constexpr uint16_t	statTimeHour (uint16_t time)
constexpr uint16_t	statTimeMinute (uint16_t time)
constexpr uint16_t	statTimeSecond (uint16_t time)
int	close (int fd)
int	findClose (int findHandle)
int	findFirst (const wchar_t *path, int *findHandle, wchar_t *name, struct findInfo *findInfoBuf)
int	findNext (int findHandle, wchar_t *name, struct findInfo *findInfoBuf)
int	fstat (int fd, struct stat *buf)
int	getAddr (int fd, int offset, const void **addr)
int	lseek (int fd, int offset, int whence)
int	mkdir (const char *path)
int	open (const char *path, int flags)
int	read (int fd, void *buf, int count)
int	remove (const char *path)
int	rename (const char *oldPath, const char *newPath)
int	stat (const char *path, struct stat *buf)
int	write (int fd, const void *buf, int count)

Variables
const int	SEEK_SET = 0
	Set the file offset to offset.
const int	SEEK_CUR = 1
	Set the file offset to the current position, plus offset bytes.
const int	SEEK_END = 2
	Set the file offset to the end of the file, plus offset bytes.
const int	OPEN_READ = 1 << 0
	Open the file as readable.
const int	OPEN_WRITE = 1 << 1
	Open the file as writable.
const int	OPEN_CREATE = 1 << 2
	Create the file, if it does not already exist.
const int	OPEN_APPEND = 1 << 4
	Opens the file with the file offset set to the end of the file.
Errors
Errors returned by file system functions. All negative numbers.
const int	ENOMEM = -1
const int	EINVAL = -2
const int	EDEVFAIL = -3
const int	EMOUNTED = -4
const int	EACCES = -5
const int	EBADFSID = -6
const int	ENOVOLUME = -7
const int	ENOPATH = -8
const int	EEXIST = -9
const int	ENAMETOOLONG = -10
const int	EOUTOFBOUND = -11
const int	EUNFORMAT = -12
const int	ENOSPC = -13
const int	ENOENT = -14
const int	EISDIRECTORY = -15
const int	ESHARE = -16
const int	EMFILE = -17
const int	EBADF = -18
const int	EEOF = -19
const int	ENOTEMPTY = -20
const int	ECLUSTERSIZEMISMATCH = -40
const int	ESYSTEM = -99

Detailed Description

Functions for interacting with the calculator's file system.

Provides an API similar to that of Unix.

The storage which appears when the calculator is attached to a PC is found under the path \\fls0\ (remember to escape the \ in strings!).

Example: reading 256 bytes from a file called test.txt from the USB flash

int fd = open("\\\\fls0\\test.txt", OPEN_READ);
if (fd < 0) {
    // An error occurred calling open
    goto exit;
}
 
uint8_t buf[256];
int ret = read(fd, buf, sizeof(buf));
if (ret < 0) {
    // An error occurred calling read
    close(fd);
    goto exit;
}
 
ret = close(fd);
if (ret < 0) {
    // An error occurred calling close
}
 
exit:

Example: writing 16 bytes to a non-existant file called f.bin in a folder test in the USB flash

int fd = open("\\\\fls0\\test\\f.bin", OPEN_WRITE | OPEN_CREATE);
if (fd < 0) {
    // An error occurred calling open
    goto exit;
}
 
uint8_t buf[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF};
int ret = write(fd, buf, sizeof(buf));
if (ret < 0) {
    // An error occurred calling write
    close(fd);
    goto exit;
}
 
ret = close(fd);
if (ret < 0) {
    // An error occurred calling close
}
 
exit:

Function Documentation

close()

int close

(

int

fd

)

Closes an open file.

Parameters

fd	The file descriptor for the open file.

Returns

0 on success, or a negative error code on failure.

findClose()

int findClose

(

int

findHandle

)

Closes a find handle.

Very, very, very bad things happen if a find handle is not closed.

Parameters

findHandle

The find handle to close.

Returns

0 on success, or a negative error code on failure.

findFirst()

int findFirst	(	const wchar_t *	path,
		int *	findHandle,
		wchar_t *	name,
		struct findInfo *	findInfoBuf
	)

Starts a find operation, locating files matching a specific path.

Can be used to list the contents of a directory by using a wildcard. For example, passing the path L"\\fls0\\*" or L"\\fls0\\*.*" matches all files and directories on the calculator's flash (not recursive, though).

To find the next file/directory which matches the path, call findNext, passing in the find handle returned by this function. Ensure the find handle is closed using findClose when the find operation is finished. Bad things happen if the handle is not closed.

Parameters

[in]	path	The path to search. May contain wildcards.
[out]	findHandle	The find handle created. Must be closed when the find operation is finished.
[out]	name	The name of the file/directory found.
[out]	findInfoBuf	Information about the found file.

Returns

0 on success, or a negative error code on failure.

findNext()

int findNext	(	int	findHandle,
		wchar_t *	name,
		struct findInfo *	findInfoBuf
	)

Returns information about the next matching file/directory in a find operation.

Parameters

	findHandle	The find handle returned from findFirst.
[out]	name	The name of the file/directory found.
[out]	findInfoBuf	Information about the found file.

Returns

0 on success, or a negative error code on failure.

fstat()

int fstat	(	int	fd,
		struct stat *	buf
	)

Retrieves information about an open file.

Parameters

	fd	The file descriptor of an open file to retrieve the information of.
[out]	buf	The retrieved information about the file.

Returns

0 on success, or a negative error code on failure.

getAddr()

int getAddr	(	int	fd,
		int	offset,
		const void **	addr
	)

Retrieves the memory address of a file.

If the file is empty or the offset would point outside of the file, EINVAL is returned.

Parameters

	fd	The file descriptor of an open file.
	offset	An offset to apply to the pointer to the file's data.
[out]	addr	The address of the file's data.

Returns

0 on success, or a negative error code on failure.

lseek()

int lseek	(	int	fd,
		int	offset,
		int	whence
	)

Repositions the file offset of the file descriptor. The new position depends on the value of both offset and whence. See lseek whence Values.

Parameters

fd	The file descriptor of an open file to change the file offset of.
offset	The new offset, relative to some point.
whence	Where offset is relative to.

Returns

The new file offset on success, or a negative error code on failure.

mkdir()

int mkdir

(

const char *

path

)

Creates a directory.

Parameters

[in]

path

The path to the directory to be created.

Returns

0 on success, or a negative error code on failure.

open()

int open	(	const char *	path,
		int	flags
	)

Opens a file on the file system.

The argument flags is fed a bitwise OR'd combination of flags. See open flags Values.

Parameters

[in]	path	The path to the file to open.
	flags	A bitfield describing the mode in which to open the file.

Returns

A file descriptor on success, or a negative error code on failure.

read()

int read	(	int	fd,
		void *	buf,
		int	count
	)

Reads up to count bytes from a file, and stores them in buf.

If count bytes cannot be read from the file, as many bytes as possible are read (i.e. between 0 and count - 1 bytes are read and stored in buf).

Parameters

	fd	The file descriptor of an open file to read from.
[out]	buf	A buffer to place the read bytes into.
	count	The maximum number of bytes to read.

Returns

The number of bytes read on success, or a negative error code on failure.

remove()

int remove

(

const char *

path

)

Deletes a file or directory.

Parameters

[in]

path

The path to the file or directory to be deleted.

Returns

0 on success, or a negative error code on failure.

rename()

int rename	(	const char *	oldPath,
		const char *	newPath
	)

Renames a file or directory.

Parameters

[in]	oldPath	The path to the file or directory to be renamed.
[in]	newPath	The path to the new name for the file or directory.

Returns

0 on success, or a negative error code on failure.

stat()

int stat	(	const char *	path,
		struct stat *	buf
	)

Retrieves information about a file.

Parameters

[in]	path	The path to the file to retrieve the information of.
[out]	buf	The retrieved information about the file.

Returns

0 on success, or a negative error code on failure.

statDateDay()

constexpr uint16_t statDateDay ( uint16_t  date )

constexpr

Retrieves the day from a struct stat date field.

Parameters

date	The date field from a struct stat.

Returns

The day encoded in the date field.

statDateMonth()

constexpr uint16_t statDateMonth ( uint16_t  date )

constexpr

Retrieves the month from a struct stat date field.

Parameters

date	The date field from a struct stat.

Returns

The month encoded in the date field.

statDateYear()

constexpr uint16_t statDateYear ( uint16_t  date )

constexpr

Retrieves the year from a struct stat date field.

Parameters

date	The date field from a struct stat.

Returns

The year encoded in the date field.

statTimeHour()

constexpr uint16_t statTimeHour ( uint16_t  time )

constexpr

Retrieves the hour from a struct stat time field.

Parameters

time	The time field from a struct stat.

Returns

The hour encoded in the time field.

statTimeMinute()

constexpr uint16_t statTimeMinute ( uint16_t  time )

constexpr

Retrieves the minute from a struct stat time field.

Parameters

time	The time field from a struct stat.

Returns

The minute encoded in the time field.

statTimeSecond()

constexpr uint16_t statTimeSecond ( uint16_t  time )

constexpr

Retrieves the second from a struct stat time field.

Has a maximum resolution of 2 seconds.

Parameters

time	The time field from a struct stat.

Returns

The second encoded in the time field.

write()

int write	(	int	fd,
		const void *	buf,
		int	count
	)

Writes count bytes from buf to a file.

Parameters

	fd	The file descriptor of an open file to write to.
[in]	buf	A buffer of bytes to write to the file.
	count	The number of bytes from buf to write to the file.

Returns

The number of bytes written on success, or a negative error code on failure.