GXBF class¶

class GXBF(handle=0)¶

GXBF class.

The GXBF class is used to access (or create) Binary files and remove (or destroy) files from use. You can also perform a variety of additional tasks, such as positioning within files, reading from files and writing to files.

ch_size(size)¶

Changes the size of a file

Parameters:	size (int) – New length in bytes

New in version 5.0.

License: Geosoft Open License

copy(b_fw)¶

Copy entire contents of a source GXBF to a destination GXBF

Parameters:	b_fw (GXBF) – Destination `GXBF`

New in version 5.0.

License: Geosoft Open License

crc(size, crc)¶

Compute CRC of a file.

Parameters:	size (int) – Number of bytes to CRC crc (int) – CRC start (use `CRC_INIT_VALUE` for new)
Returns:	CRC Value
Return type:	int

New in version 5.0.

License: Geosoft Open License

classmethod create(file, status)¶

Create GXBF object.

Parameters:	file (str) – File name to open (“” is a temporary file) status (int) – BF_OPEN_MODE constants
Returns:	`GXBF` Object
Return type:	GXBF

New in version 5.0.

License: Geosoft Open License

Note: Run-time specific directory paths may be added the the front of file names as follows:

<geosoft> the main Geosoft installation directory <geosoft2> the secondary Geosoft installation directory <geotemp> the Geosoft temporary file directory <windows> the operating system Windows directory <system> the operating system system directory <other> other environment variables

For example “<geosoft>/user/csv/datum.csv”

classmethod create_sbf(sbf, file, status)¶

Create GXBF object inside an GXSBF.

Parameters:	sbf (GXSBF) – Storage file (str) – File name to open (“” is a temporary file) status (int) – BF_OPEN_MODE constants
Returns:	`GXBF` Object
Return type:	GXBF

New in version 5.0.

License: Geosoft Open License

Note: see sbf.gxh

eof()¶

Returns 1 if at the end of the file

Returns:	1 if at the end of the file, 0 if not at the end of the file
Return type:	int

New in version 5.0.

License: Geosoft Open License

is_null()¶

Check if this is a null (undefined) instance

Returns:	True if this is a null (undefined) instance, False otherwise.
Return type:	bool

classmethod null()¶

A null (undefined) instance of GXBF

Returns:	A null `GXBF`
Return type:	GXBF

query_write()¶

Check if you can write to the GXBF.

Returns:	0 - No 1 - Yes
Return type:	int

New in version 5.1.1.

License: Geosoft Open License

read_binary_string(bytes, encoding, data)¶

Reads string data from current position in GXBF

Parameters:	bytes (int) – Number of bytes to read encoding (int) – BF_ENCODE constants data (str_ref) – Data

New in version 6.3.

License: Geosoft Open License

read_double(type, data)¶

Reads real data from current position in GXBF

Parameters:	type (int) – GS_TYPES constants and BF_BYTEORDER constants data (float_ref) – Data

New in version 5.0.

License: Geosoft Open License

Note: If the data source may be in byte order different from that required by the reader, you can add the source byte-order to the GXBF elelment type. The byte order will be swapped if required. For example, to write out a real number 3.5 with Most-Significant_Byte first (Mortorola) convention:

write_double,3.5).

If a byte order is not specified, the source is assumed to be in the native byte order of the reading/writing computer.

read_int(type, data)¶

Reads int data from current position in GXBF

Parameters:	type (int) – GS_TYPES constants and BF_BYTEORDER constants data (int_ref) – Data

New in version 5.0.

License: Geosoft Open License

Note: If the data source may be in byte order different from that required by the reader, you can add the source byte-order to the GXBF elelment type. The byte order will be swapped if required. For example, to write out a real number 3.5 with Most-Significant_Byte first (Mortorola) convention:

write_double,3.5).

If a byte order is not specified, the source is assumed to be in the native byte order of the reading/writing computer.

read_vv(type, vv)¶

Read data to a GXVV from current position in GXBF

Parameters:	type (int) – GS_TYPES constants and BF_BYTEORDER constants vv (GXVV) – `GXVV` data to read, `GXVV` length is read

New in version 5.0.

License: Geosoft Open License

Note: If the data source may be in byte order different from that required by the reader, you can add the source byte-order to the GXBF elelment type. The byte order will be swapped if required. For example, to write out a real number 3.5 with Most-Significant_Byte first (Mortorola) convention:

write_double,3.5).

If a byte order is not specified, the source is assumed to be in the native byte order of the reading/writing computer.

seek(offset, ref)¶

Moves file position

Parameters:	offset (int) – Number of bytes from reference point ref (int) – BF_SEEK constants

New in version 5.0.

License: Geosoft Open License

Note: Terminates if attempt to move past the end of a read-only file.

set_destroy_status(status)¶

Set the flag to delete the file on close

Parameters:	status (int) – BF_CLOSE constants

New in version 6.0.

License: Geosoft Open License

size()¶

Returns the file length

Returns:	File size in bytes.
Return type:	int

New in version 5.0.

License: Geosoft Open License

tell()¶

Returns current position of file pointer in bytes

Returns:	Current file pointer location
Return type:	int

New in version 5.0.

License: Geosoft Open License

write_binary_string(encoding, data)¶

Write a binary string to a GXBF

Parameters:	encoding (int) – BF_ENCODE constants data (str) – String to write out

New in version 6.3.

License: Geosoft Open License

write_data_null()¶

Writes a null byte (0) to GXBF

New in version 5.0.

License: Geosoft Open License

write_double(type, data)¶

Writes real to the GXBF

Parameters:	type (int) – GS_TYPES constants and BF_BYTEORDER constants data (float) – Data

New in version 5.0.

License: Geosoft Open License

Note: See comments on byte order for the Read.. functions if you want to enforce a certain byte order.

If a byte order is not specified, the data is written in the native byte order of the writing computer.

write_int(type, data)¶

Writes int to the GXBF

Parameters:	type (int) – GS_TYPES constants and BF_BYTEORDER constants data (int) – Data

New in version 5.0.

License: Geosoft Open License

Note: See comments on byte order for the Read.. functions if you want to enforce a certain byte order.

If a byte order is not specified, the data is written in the native byte order of the writing computer.

write_vv(type, vv)¶

Writes GXVV to the GXBF

Parameters:	type (int) – GS_TYPES constants and BF_BYTEORDER constants vv (GXVV) – Data

New in version 5.0.

License: Geosoft Open License

Note: See comments on byte order for the Read.. functions if you want to enforce a certain byte order.

If a byte order is not specified, the data is written in the native byte order of the writing computer.

BF_BYTEORDER constants¶

Byte order for read/write

BF_BYTEORDER_LSB¶

Least significant byte first (Intel, Windows)

gxapi.BF_BYTEORDER_LSB = 256

BF_BYTEORDER_MSB¶

Most significant byte first (Mororola, Sun)

gxapi.BF_BYTEORDER_MSB = 512

BF_CLOSE constants¶

Close Flags

BF_KEEP¶

Bf keep

gxapi.BF_KEEP = 0

BF_DELETE¶

Bf delete

gxapi.BF_DELETE = 1

BF_ENCODE constants¶

The way a string is encoded

BF_ENCODE_ANSI¶

String is stored as ANSI code page

gxapi.BF_ENCODE_ANSI = 0

BF_ENCODE_UTF8¶

String is stored as UTF8 constants

gxapi.BF_ENCODE_UTF8 = 1

BF_OPEN_MODE constants¶

Open Status

BF_READ¶

Read only

gxapi.BF_READ = 0

BF_READWRITE_NEW¶

Erases existing file

gxapi.BF_READWRITE_NEW = 1

BF_READWRITE_OLD¶

File must pre-exist

gxapi.BF_READWRITE_OLD = 2

BF_READWRITE_APP¶

Open and append onto pre-existing file (cannot be read from)

gxapi.BF_READWRITE_APP = 4

BF_SEEK constants¶

Seek Location

BF_SEEK_START¶

Start

gxapi.BF_SEEK_START = 0

BF_SEEK_CURRENT¶

Current

gxapi.BF_SEEK_CURRENT = 1

BF_SEEK_EOF¶

Eof

gxapi.BF_SEEK_EOF = 2

Table Of Contents

This Page

GXBF class¶

BF_BYTEORDER constants¶

BF_CLOSE constants¶

BF_ENCODE constants¶

BF_OPEN_MODE constants¶

BF_SEEK constants¶