COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

Other rules depend on the category of the system file name. The categories are:
• Permanent Disk File Names
• Temporary Disk File Names
• Nondisk File (Device) Names
For information about process file names, see Processes Handled as Files.
Permanent Disk File Names
Permanent disk files are named when they are created. After being created, a permanent disk file
remains on the disk until explicitly purged.
node-name
is a backward slash (\) followed by an alphabetic character and up to six alphanumeric
characters. Example: \mynode. Default: default node.
volume-name
is a dollar sign ($) followed by an alphabetic character and up to six alphanumeric characters.
Example: $volume3. Default: default volume.
subvolume-name
is an alphabetic character followed by up to seven alphanumeric characters. Example: subvol10.
Default: default subvolume.
file-id
is an alphabetic character followed by up to seven alphanumeric characters. Example: file1234.
An example of a permanent disk file name is \mynode.$volume3.subvol10.file1234. If
\mynode.$volume3.subvol10 is the default subvolume, then these are equivalent:
\mynode.$volume3.subvol10.file1234
$volume3.subvol10.file1234
subvol10.file1234
file1234
The default node, volume, and subvolume are established with the =_DEFAULTS DEFINE and can
be changed with TACL commands. For details, see the TACL Reference Manual.
Temporary Disk File Names
The two ways to create a temporary disk file are:
• In the file-control entry, with the clause SELECT … ASSIGN #TEMP
• With the TACL command ASSIGN … #TEMP
Temporary disk files are named by the file system when a program creates them. The program
cannot specify a system file name for a temporary file. When the program closes a temporary disk
file, the file system purges it. For more information about temporary disk files, see the Guardian
Programmer’s Guide.
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