File systems
Record-oriented files that have sequential, relative, indexed, or line-sequential organization are accessed through a file system.
- Db2® (Db2 relational database) file system
- Lets batch COBOL programs create and access CICS® files that are stored in Db2.
- SdU (SMARTdata Utilities) file system
- Files in the SdU file system can be shared with PL/I programs.
- SFS (CICS Structured File Server) file system
- One of the file systems used by CICS. CICS SFS is supplied as part of CICS. SFS files can be shared with PL/I programs.
- STL (standard language) file system
- Provides the basic facilities for local files.
- QSAM (queued sequential access method) file system
- Lets COBOL programs access QSAM files that are transferred from the mainframe to Linux using FTP.
- RSD (record sequential delimited) file system
- Lets COBOL programs share data with programs written in other languages. RSD files are sequential only, with fixed or variable-length records, and support all COBOL data types in records. Text data in records can be edited by most file editors.
You can specify the file system for a given sequential, relative, or indexed file in any of several ways. For details, see the related reference about precedence of file-system determination.
Record-oriented files that have line-sequential organization can be accessed only through the LSQ (line sequential) file system.
Db2 files are managed by the
DB2
command-line utility; SFS files are managed by the sfsadmin
command-line utility. All other files exist in the line sequential Linux file system, and are managed by standard Linux commands such as cp
, ls
,
mv
, and rm
. (Do not however use the cp
or
mv
command for SdU files, which consist of multiple component files that refer to
one another internally.)
All the file systems let you use COBOL statements to read and write COBOL files. Most programs have the same behaviors in all file systems. However, files written using one file system cannot be read using a different file system.
- Code
ASSIGN TO RSD-assignment-name
in your program. - Set the following environment variable:
export COBRTOPT=FS=RSD:
. - Set the following command:
export assignment-name=RSD-os-file-name
.
- Use the RSD file system for transaction files that are used to update the database file.
- Use the STL file system for indexed or relative database files.
- Use the RSD file system for output files.
- All other files exist in the native Linux file system.