Files in Unix systems and Windows systems, like POSIX files in BS2000 systems, have no structure and no file attributes that provide information on the coding. Although they have no structure either, Windows files can be distinguished on the basis of their file extensions (e.g. “txt” for text and “exe” for executable files).
For transfer with Windows or Unix systems, you can therefore define the following file types:
text
unstructured binary data
binary data structured in records (user format)
Text format
A file that is sent in text format from Windows or Unix systems, must be a pure text file with a record structure defined by linefeed characters in Unix systems or Carriage Return and linefeed in Windows. The length of a line is limited, e.g. 98403 bytes in Windows systems. For the transfer, the end-of-line character is removed from every line.
During transfers from BS2000 or z/OS systems to Windows or Unix systems, the end-ofline character is inserted into the sentence length already in the remote system. The text and the sentence lengths are preserved. The line length is restricted, e.g. to 98304 bytes in Windows systems. The maximum sentence length during a text file transfer depends on the operating system.
When communicating with partner systems as of openFT V10, it is also possible to transfer Unicode files; see section "Transferring 7-bit, 8-bit and Unicode files".
Tabulator and blank line expansion
During transfers of text files, openFT carries out a tabulator and blank line expansion if necessary. This means that blank characters will be transferred instead of a tabulator, and a line with a blank character will be transferred instead of a blank line. During this, the following cases will be different for openFT partners:
Initiator | Direction | Responder | Expansion (yes/no) |
Unix system, Windows system | Send | Unix system, Windows system | no, optional yes1 |
Unix system, Windows system | Fetch | Unix system, Windows system | no |
Unix system, Windows system | Send | BS2000, z/OS | yes, optional no1 |
Unix system, Windows system | Fetch | BS2000, z/OS | no (not relevant) |
BS2000, z/OS | Send | Unix system, Windows system | no (not relevant) |
BS2000, z/OS | Fetch | Unix system, Windows system | yes (at the initiator) |
BS2000, z/OS | Send and | BS2000, z/OS | no |
During file transfer with FTAM partners, there is no blank line expansion. Tabulators are expanded during transfers using the character set Graphic String, but not in the General String. For more detailed information on FTAM character sets, see also section "FTAM files".
Binary format
When “Binary format” is specified, it is assumed that the file to be transferred contains an unstructured sequence of binary data. In the receiving system, a file with an undefined record length (i.e. without end-of-line characters) is generated. The binary data remains the same.
User format
When sending a file, it is assumed that length fields divide up the file into records. The first two bytes of each record must indicate its length, including the length of the record length field. When the file is fetched, this length data is generated in accordance with the actual record lengths in the remote system. The contents of the records are treated like binary data, i.e. not converted.
Both the record structure and the binary data remain unchanged when a file is transferred. The record length fields are stored in all Unix and Windows systems starting with the most significant byte. The maximum permitted record length within a file in the user format depends on the operating system.