Дополнительные команды AVR-DOS
Список команд AVR-DOS — список функций библиотеки AVR-DOS.
Содержание
Диск/Директория
FileDate
Возвращает дату создания или последнего изменения файла.
sDate = FileDate ()
sDate = FileDate (file)
| sDate(String) | Дата создания или изменения(?) файла |
| File(String) | Имя файла в текущей директории[1][2] |
Пример вызова:
<source lang="vb"> Print "File demo" Print Filelen( "josef.img") ; " length" ' length of file Print Filetime( "josef.img") ; " time" ' time file was changed Print Filedate( "josef.img") ; " date" ' file date </source>
FileTime
Возвращает время создания или последнего изменения файла.
sTime = FileTime ()
sTime = FileTime (file)
| sTime(String) | Время создания или изменения(?) файла |
| File(String) | Имя файла в текущей директории[1][2] |
Пример вызова:
<source lang="vb"> Print "File demo" Print Filelen( "josef.img") ; " length" ' length of file Print Filetime( "josef.img") ; " time" ' time file was changed Print Filedate( "josef.img") ; " date" ' file date </source>
Файлы
Flush
Скидывает кеш текущего файла на диск и обновляет информацию раздела, директории.
Процедура осуществляет запись всей несохраненной информации о/в файле на диск. Обычно запись на диск производится при закрытии файлового потока или переходе на другой сектор файла, однако вы можете поменять параметр cFATDirSaveAtEnd, в этом случае вам придется принудительно сбрасывать изменения файла на диск.
Flush #bFileNumber
Flush
| BFileNumber(Byte) | Идентификационный номер открытого файлового потока[3]. Если не указан, то изменения всех открытых файлов сбрасываются на диск. |
Пример вызова:
<source lang="vb"> $include "startup.inc"
'open the file in BINARY mode Open "test.biN" For Binary As #2 Put #2 , B ' write a byte Put #2 , W ' write a word Put #2 , L ' write a long Ltemp = Loc(#2) + 1 ' get the position of the next byte Print Ltemp ; " LOC" ' store the location of the file pointer Print Lof(#2) ; " length of file" Print Fileattr(#2) ; " file mode" ' should be 32 for binary Put #2 , Sn ' write a single Put #2 , Stxt ' write a string
Flush #2 ' flush to disk Close #2 </source>
Get
Reads a byte from the hardware or software UART. Reads data from a file opened in BINARY mode.
GET in combination with the software/hardware UART is provided for compatibility with BASCOM-8051. It reads one byte. GET in combination with the AVR-DOS filesystem is very flexible and versatile. It works on files opened in BINARY mode and you can reads all data types. By default you only need to provide the variable name. When the variable is a byte, 1 byte wil be read. When the variable is a word or integer, 2 bytes will be read. When the variable is a long or single, 4 bytes will be read. When the variable is a string, the number of bytes that will be read is equal to the dimensioned size of the string. DIM S as string * 10 , would read 10 bytes. Note that when you specify the length for a string, the maximum length is 255. The maximum length for a non-string array is 65535. <source lang="vb"> Example : GET #1 , var ,,2 ‘ read 2 bytes, start at current position GET #1, var , PS ‘ start at position stored in long PS GET #1, var , PS, 2 ‘ start at position stored in long PS and read 2 bytes</source>
GET #channel, var
GET #channel, var , [pos] [, length]
| #channel(...) | A channel number, which identifies an opened file. This can be a hard coded constant or a variable |
| Var(...) | The variable or variable array that will be assigned with the data from the file |
| Pos(...) | This is an optional parameter that may be used to specify the postion where the reading must start from. This must be a long variable |
| Length(...) | This is an optional parameter that may be used to specify how many bytes must be read from the file. |
Пример вызова:
<source lang="vb"> 'for the binary file demo we need some variables of different types Dim B As Byte , W As Word , L As Long , Sn As Single , Ltemp As Long Dim Stxt As String * 10 B = 1 : W = 50000 : L = 12345678 : Sn = 123.45 : Stxt = "test"
'open the file in BINARY mode Open "test.biN" For Binary As #2 Put #2 , B ' write a byte Put #2 , W ' write a word Put #2 , L ' write a long Ltemp = Loc(#2) + 1 ' get the position of the next byte Print Ltemp ; " LOC" ' store the location of the file pointer Print Seek(#2) ; " = LOC+1"
Print Lof(#2) ; " length of file" Print Fileattr(#2) ; " file mode" ' should be 32 for binary Put #2 , Sn ' write a single Put #2 , Stxt ' write a string
Flush #2 ' flush to disk Close #2
'now open the file again and write only the single Open "test.bin" For Binary As #2 L = 1 'specify the file position B = Seek(#2 , L) ' reset is the same as using SEEK #2,L Get #2 , B ' get the byte Get #2 , W ' get the word Get #2 , L ' get the long Get #2 , Sn ' get the single Get #2 , Stxt ' get the string Close #2 </source>
Put
Writes a byte to the hardware or software UART. Writes data to a file opened in BINARY mode.
PUT in combination with the software/hardware UART is provided for compatibility with BASCOM-8051. It writes one byte PUT in combination with the AVR-DOS filesystem is very flexible and versatile. It works on files opened in BINARY mode and you can write all data types. By default you only need to provide the variable name. When the variable is a byte, 1 byte wil be written. When the variable is a word or integer, 2 bytes will be written. When the variable is a long or single, 4 bytes will be written. When the variable is a string, the number of bytes that will be written is equal to the dimensioned size of the string. DIM S as string * 10 , would write 10 bytes. Note that when you specify the length for a string, the maximum length is 255. The maximum length for a non-string array is 65535. Example: <source lang="vb"> PUT #1, var PUT #1, var , , 2 ‘ write 2 bytes at default position PUT #1, var ,PS, 2 ‘ write 2 bytes at location storied in variable PS</source>
PUT #channel, var
PUT #channel, var ,[pos] [,length]
| #channel(...) | A channel number, which identifies an opened file. This can be a hard coded constant or a variable. |
| Var(...) | The variable or variable array that will be written to the file |
| Pos(...) | This is an optional parameter that may be used to specify the postion where the data must be written to. This must be a long variable. |
| Length(...) | This is an optional parameter that may be used to specify how many bytes must be written to the file. |
Пример вызова:
<source lang="vb"> 'for the binary file demo we need some variables of different types Dim B As Byte , W As Word , L As Long , Sn As Single , Ltemp As Long Dim Stxt As String * 10 B = 1 : W = 50000 : L = 12345678 : Sn = 123.45 : Stxt = "test"
'open the file in BINARY mode Open "test.biN" For Binary As #2 Put #2 , B ' write a byte Put #2 , W ' write a word Put #2 , L ' write a long Ltemp = Loc(#2) + 1 ' get the position of the next byte Print Ltemp ; " LOC" ' store the location of the file pointer Print Seek(#2) ; " = LOC+1"
Print Lof(#2) ; " length of file" Print Fileattr(#2) ; " file mode" ' should be 32 for binary Put #2 , Sn ' write a single Put #2 , Stxt ' write a string
Flush #2 ' flush to disk Close #2
'now open the file again and write only the single Open "test.bin" For Binary As #2 L = 1 'specify the file position B = Seek(#2 , L) ' reset is the same as using SEEK #2,L Get #2 , B ' get the byte Get #2 , W ' get the word Get #2 , L ' get the long Get #2 , Sn ' get the single Get #2 , Stxt ' get the string Close #2 </source>
Seek
Function: Returns the position of the next Byte to be read or written. Statement: Sets the position of the next Byte to be read or written.
This function returns the position of the next Byte to be read or written. If an error occures, 0 is returned. Check DOS-Error in variable gbDOSError[4].. The statetement also returns an error in the gbDOSerror variable in the event that an error occurs. You can for example not set the fileposition behinds the filesize. In QB/VB the file is filled with 0 bytes when you set the filepointer behind the size of the file. For embedded systems this does not seem a good idea. Seek and Loc seems to do the same function, but take care : the seek function will return the position of the next read/write, while the Loc function returns the position of the last read/write. You may say that Seek = Loc+1. Difference with QB In QB/VB you can use seek to make the file bigger. When a file is 100 bytes long, setting the filepointer to 200 will increase the file with 0 bytes. By design this is not the case in AVR-DOS.
Function: NextReadWrite = Seek (#bFileNumber)
Statement: Seek #bFileNumber, NewPos)
| bFileNumber(Byte) | Filenumber, which identifies an opened file |
| NextReadWrite(Long) | A Long Variable, which is assigned with the Position of the next Byte to be read or written (1-based) |
| NewPos(Long) | A Long variable that holds the new position the filepointer must be set too. |
Пример вызова:
<source lang="vb"> Open "test.biN" For Binary As #2 Put #2 , B ' write a byte Put #2 , W ' write a word Put #2 , L ' write a long Ltemp = Loc(#2) + 1 ' get the position of the next byte Print Ltemp ; " LOC" ' store the location of the file pointer Print Seek(#2) ; " = LOC+1"
Close #2
'now open the file again and write only the single Open "test.bin" For Binary As #2 Seek #2 , Ltemp ' set the filepointer Sn = 1.23 ' change the single value so we can check it better Put #2 , Sn = 1 'specify the file position Close #2 </source>
Свойства файла
LOC
Returns the position of last read or written Byte of the file.
This function returns the position of the last read or written Byte. If an error occurs, 0 is returned. Check DOS-Error in variable gbDOSError[4].. If the file position pointer is changed with the command SEEK, this function can not be used till the next read/write operation. Difference with QB This function differs from QB. In QB the byte position is divided by 128.
lLastReadWritten = Loc (#bFileNumber)
| bFileNumber(Byte) | Filenumber, which identifies an opened file |
| lLastReadWritten(Long) | Variable, whichsigned with the Position of last read or written Byte (1-based) |
Пример вызова:
<source lang="vb"> 'open the file in BINARY mode Open "test.biN" For Binary As #2 Put #2 , B ' write a byte Put #2 , W ' write a word Put #2 , L ' write a long Ltemp = Loc(#2) + 1 ' get the position of the next byte Print Ltemp ; " LOC" ' store the location of the file pointer Print Lof(#2) ; " length of file" Print Fileattr(#2) ; " file mode" ' should be 32 for binary Put #2 , Sn ' write a single Put #2 , Stxt ' write a string
Flush #2 ' flush to disk Close #2 </source>
FileAttr
Возвращает режим открытия файлового потока.
bFileAttribut = FileAttr (bFileNumber)
| bFileAttribut(Long) | Режим:
1 - INPUT |
| bFileNumber(Byte) | Идентификационный номер открытого файлового потока[3] |
Пример вызова:
<source lang="vb"> 'open the file in BINARY mode Open "test.biN" For Binary As #2 Print Fileattr(#2) ; " file mode" ' should be 32 for binary Put #2 , Sn ' write a single Put #2 , Stxt ' write a string Close #2 </source>
Другие
Bload
Writes the Content of a File into SRAM.
This function writes the content of a file to a desired space in SRAM. A free handle is needed for this function.
BLoad sFileName, wSRAMPointer
| sFileName(Long) | Name of the File to be read |
| wSRAMPointer(Word) | Variable, which holds the SRAM Address to which the content of the file should be written |
Пример вызова:
<source lang="vb"> 'now the good old bsave and bload Dim Ar(100) As Byte , I As Byte For I = 1 To 100 Ar(i) = I ' fill the array Next
Wait 2
W = Varptr(ar(1)) Bsave "josef.img" , W , 100 For I = 1 To 100 Ar(i) = 0 ' reset the array Next
Bload "josef.img" , W ' Josef you are amazing !
For I = 1 To 10 Print Ar(i) ; " " ; Next Print </source>
Bsave
Save a range in SRAM to a Fileю
This function writes a range from the SRAM to a file. A free file handle is needed for this function.
BSave sFileName, wSRAMPointer, wLength
| sFileName(Long) | Name of the File to be written |
| wSRAMPointer(Word) | Variable, which holds the SRAM Address, from where SRAM should be written to a File |
| wLength(Word) | Count of Bytes from SRAM, which should be written to the file |
Пример вызова:
<source lang="vb">'now the good old bsave and bload Dim Ar(100) As Byte , I As Byte For I = 1 To 100 Ar(i) = I ' fill the array Next
Wait 2
W = Varptr(ar(1)) Bsave "josef.img" , W , 100 For I = 1 To 100 Ar(i) = 0 ' reset the array Next
Bload "josef.img" , W ' Josef you are amazing !
For I = 1 To 10 Print Ar(i) ; " " ; Next Print </source>
Сноски
- ↑ 1 2 8.3: имя - 8 символов, расширение - 3 символа, разделитель(точка) - 1 символ, всего не более 12 символов
- ↑ 1 2 Если не указано, параметром считается последний файл, выбранный с помощью DIR
- ↑ 1 2 Принадлежит целому множеству 0..255, может быть переменной или константой. Используйте числа 1..127 для пользовательских идентификаторов. Для получения свободного идентификатора используйте функцию FreeFile(возвращает 128..255)
- ↑ 1 2 Коды ошибок
