Open PL/I supports a number of non-standard TITLE options that can be used to indicate the type of file being opened. These are as follows:
-SAM [n]
-DAM [n]
-NOSIZE
-APPEND [n]
-DELABORT [n]
where n is an integer indicating that the file has fixed-length records of length n bytes.
These options are included in the operand of the TITLE option immediately following the filename and separated from it by one or more spaces, as shown in the following examples:
TITLE('recfile.dat -SAM 80')
TITLE('keyfile -DAM')
The -SAM and -APPEND options can be used with stream files, in which case the length, if specified, is ignored. -SAM is never required for stream files.
-SAM [n] specifies that the file is a consecutive file. If n is specified when the file is created, the file is created with records of fixed length n. The maximum value for n is 131,017 bytes. If n is not specified when the file is created, records written to the file can be of any length and of varying lengths. If -SAM is used when opening a file for OUTPUT, if the file already exists, it is deleted and a new file is created.
-DAM [n] specifies that the file is a relative record I/O file. If n is specified when the file is created, the file is created with records of fixed length n. If n is not specified when the file is created, the file is created as a variable-length record file. If -NOSIZE is not also specified, this length n includes the two bytes that are added as a halfword of length information at the beginning of each record.
-NOSIZE can be used alone or in combination with -DAM [n]. It specifies that the length halfword is not included at the beginning of each record. If -NOSIZE is used without -DAM [n], -DAM is implied.
-APPEND [n] has the same meaning as -SAM, except that when used in opening a file for OUTPUT, it causes an already existing file to be appended to rather than replaced.
-DELABORT causes the file to be deleted when it is closed.
If a file is opened for OUTPUT and none of these TITLE options is specified, and there is no ENVIRONMENT attribute in the file declaration, if the opening is for a DIRECT file, -DAM is assumed, and if the opening is not for a DIRECT file, -SAM is assumed.