The input and output files read and written by the Tachyon Linkage Editor are similar in concept, use and format with those read and written by IBMs z/OS Binder. The primary input (SYSIN) is from one or more files containing control statements and/or object records. The primary input can cause files to be read from secondary sources (SYSLIB and SYSLMOD). The output files include the load modules (SYSLMOD), the listing (SYSPRINT) and the messages (SYSTERM).
The z/OS Binder defines SYSLIB and SYSLMOD as partitioned data sets. The Tachyon Linkage Editor simulates partitioned data sets as groups of workstation files in a directory. The names of files accessed like partitioned data set (PDS) members must follow the rules for PDS member names and have a common file name extention. The Tachyon Linkage Editor requires that a path pattern be provided to define the group of files to be treated as a simulated partitioned data set. The path pattern starts with the directory name followed by either &M or &m which is then followed by the file name extension. e.g. C:\MACLIB\&M.MAC If the directory name is omitted, the current working directory is used. The file name extension is also optional. The actual file name is generated by the Tachyon Linkage Editor by replacing the &M or &m with the member name whenever a PDS member is to be accessed. &M is replaced by the member name in upper case. &m is replaced by the member name in lower case.
The files accessed by the Tachyon Update Utility are:
The Tachon Linkage Editor detects if a file contains ASCII by checking the first character of the file. If the first character is an ASCII blank, an ASCII asterisk, an ASCII line feed or ASCII carriage return character, the entire file is processed as an ASCII text file. If the first character is an EBCDIC blank, an EBCDIC asterisk or an EBCDIC new line character and an EBCDIC new line character appears in the first 81 bytes, the entire file is processed as an EBCDIC text file. If none of these are true, the file is processed as fixed-length 80-byte EBCDIC records. If a text line is shorter than 80 characters, it is padded with blanks. If a text line is longer than 80 characters, the extra characters are ignored.
The primary input files must be specified on the command line or via the SYSIN DD JCL statement.
When a member is to be read from SYSLIB, the &m or &M in each path pattern is in turn replaced by the requested member name and the Tachyon Linkage Editor checks if the resulting file name exists. The first valid file name stops the search. Like the primary input files, the secondary input files may also contain EBCDIC object records and ASCII or EBCDIC control statements.
When the Tachyon Linkage Editor is invoked via JCL, the SYSLMOD DD statement is required to define the output simulated partitioned data set. A member name may be specified with the SYSLMOD data set name to set the default load module name. When the Tachyon Linkage Editor is invoked via the command line, the path pattern and default member name are specified via the -syslmod and -o parameters.
When the Tachyon Linkage Editor is invoked via JCL, the SYSPRINT DD statement is required to define the listing file. When the Tachyon Linkage Editor is invoked via the command line, the listing file is optional and is specified via the -sysprint command line parameter.