Filename Conventions

A file is identified in a COBOL program by a filename which is a user-defined word. Outside the COBOL system it is identified by a filename which must be in an external, operating-system format. There are four components:

A drive
A path
A base-name
An extension

The maximum length of the filename is 259 characters (Windows) and 1023 characters (UNIX).

COBOL imposes no other limits, but in order for the operating system to handle the filename correctly, any operating system limits must be observed when the program is run.

The following restrictions apply when naming your files:

Avoid using the following characters when you are creating Internet applications: % # ( ) @.
The Micro Focus COBOL products available on UNIX contain components that do not handle long filenames and filenames and folder names containing spaces. Avoid using long names and names containing spaces for files that will be published to UNIX.
The Oracle 1.8 version of Pro*Cobol does not support filenames that contain spaces.