The TMReadFile API call reads from the file specified by the file handle number 'file_handle' and copies it into the buffer 'read_buffer', not to exceed ‘buff_size’ bytes (which should be the size of the read_buffer being provided). 'file_handle' must be set as a result of a call to TMOpenFile. If the file to read is an ‘add’ file with extension 100 decimal then the file length will be in page increments. For example if the last data byte is in the 30th byte of the file, the length will go to the end of the page which would give a length of (2*28) or 56 bytes. If the file to read is a ‘Monetary File ‘ with extension 101, the length of the buffer is at least 36 bytes long (28 bytes for the ‘Monetary File’ + 8 bytes for the Counter and Tamper bytes to append).
For a description of the above types, see the TMEX Type Descriptions.
Parameters
session_handle
Specifies the session handle returned from the API function TMExtendedStartSession that specifies the desired 1-Wire network port. This parameter is required by most TMEX API functions.
state_buffer
Specifies a pointer to a memory location that TMEX keeps all of the state information for the 1-Wire networks. This parameter is required by most TMEX API functions.
file_handle
Specifies a file handle of the file to read.
read_buffer
Specifies a pointer to a buffer that will hold the data read from the file. It must be at least ‘max_read’ bytes long.
buff_size
Specifies the size of ‘read_buffer’ in bytes. If the file length is longer than ‘buff_size’, an error is returned.
Return Value
>= 0 => file read, and this is the number of bytes
<0 => TMEX File Operations Error Return Code
See Also