Libs-dev/libio

Right now, libio provides API to only work with files (although other communication types like pipes were also planned initially)

By default, library is compiled to use OEM file names. Support for Unicode file names is also present but requires include file to be changed and library to be recompiled.

In most cases, libio follows POSIX function prototypes. POSIX equivalents are specified for each function, where applicable.

Functions (enumerating files)

file_find_first

Find first file with matching attributes and mask in specified directory.

Prototype:

proc file.find_first _dir, _mask, _attr

Arguments:

_dir → asciiz

directory path to search in

_mask → asciiz

file mask, with use of wildcards (a.k.a. shell patterns)

_attr → dword

file attributes mask (combination of FA_* constants)

Result:

eax → FileInfo*

0 (error) / matched file data pointer (acts as find descriptor)

file_find_next

Find next file matching criteria.

Prototype:

proc file.find_next _findd

Arguments:

_findd → FileInfo*

find descriptor (see file_find_first)

Result:

eax → FileInfo*

0 (error) / matched file data pointer (acts as find descriptor)

file_find_close

Close find descriptor and free memory.

Prototype:

proc file.find_close _findd

Arguments:

_findd → FileInfo*

find descriptor (see file_find_first)

Result:

eax → dword

result of memory freeing routine

Functions (working with specific file)

file_size

Get file size.

Prototype:

proc file.size _name

Arguments:

_name → asciiz

path to file (full or relative)

Result:

ebx (attention: ebx, not eax) → dword

-1 (error) / file size (in bytes, up to 2G)

Notes:

call file_err to obtain extended error information

file_open

Open file.

Prototype:

proc file.open _name, _mode

Arguments:

_name → asciiz

path to file (full or relative)

_mode → dword

mode to open file in (combination of O_* constants)

Result:

eax → InternalFileInfo*

0 (error) / file descriptor

Notes:

call file_err to obtain extended error information

POSIX equivalent:

FILE *result = fopen(_name, _mode);

file_read

Read data from file.

Prototype:

proc file.read _filed, _buf, _buflen

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

_buf → byte*

buffer to put read data to

_buflen → dword

buffer size (number of bytes to be read from file)

Result:

eax → dword

-1 (error) / number of bytes read

Notes:

call file_err to obtain extended error information

POSIX equivalent:

size_t result = fread(_buf, _buflen, 1, _filed);

file_write

Write data to file.

Prototype:

proc file.write _filed, _buf, _buflen

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

_buf → byte*

buffer to get write data from

_buflen → dword

buffer size (number of bytes to be written to file)

Result:

eax → dword

-1 (error) / number of bytes written

Notes:

call file_err to obtain extended error information

POSIX equivalent:

size_t result = fwrite(_buf, _buflen, 1, _filed);

file_seek

Set file pointer position.

Prototype:

proc file.seek _filed, _where, _origin

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

_where → dword

position in file (in bytes) counted from specified origin

_origin → dword

origin from where to set the position (one of SEEK_* constants)

Result:

eax → dword

-1 (error) / 0

Notes:

call file_err to obtain extended error information

POSIX equivalent:

int result = fseek(_filed, _where, _origin);

file_iseof

Determine if file pointer is at the end of file.

Prototype:

proc file.eof? _filed

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

Result:

eax → dword

false / true

Notes:

call file_err to obtain extended error information

POSIX equivalent:

int result = feof(_filed);

file_truncate (file_seteof)

Truncate file size to current file pointer position:

Prototype:

proc file.truncate _filed

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

Result:

eax → dword

-1 (error) / 0

Notes:

call file_err to obtain extended error information

POSIX equivalent:

int result = ftruncate(fileno(_filed), ftell(_filed));

file_tell

Get current file pointer position.

Prototype:

proc file.tell _filed

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

Result:

eax → dword

-1 (error) / file pointer position

Notes:

call file_err to obtain extended error information

POSIX equivalent:

long result = ftell(_filed);

file_close

Close file.

Prototype:

proc file.close _filed

Arguments:

_filed → InternalFileInfo*

file descriptor (see file_open)

Result:

eax → dword

-1 (error) / 0

Notes:

call file_err to obtain extended error information

POSIX equivalent:

int result = fclose(_filed);

file_err

Not yet implemented. It was planned to give an extended information about errors that occur.