4.2.3.2.1 Assignment Name for Non-Environment Variables and Literals
If a literal or non-data-name word is specified for the name, the
assignment name is processed as follows:
___ ASSIGNment name format _____________________________________________
| |
| >>__ __________ __ _________________ ________________________________> |
| |_comment-_| |_file system ID-_| |
| |
| >__ _system file name__ _______________ _ __________________________>< |
| | |_| alt_index |_| | |
| |_environment variable name___________| |
| |
| alt_index: |
| <______________________________ |
| |__(__alt-inx-file-name-1___ ____________________________ |__)_______| |
| |_,__ _____________________ _| |
| |_alt-inx-file-name-2_| |
| |
|________________________________________________________________________|
Comment
All characters to the left of the system-file ID are treated as
comments. Comments can be hyphenated, for example, my-comment
or this-is-my-comment.
File-system ID
The first three characters of the file-system ID are used to
determine the file-system identifier. If the character string
for the file-system ID is less than three characters, then the
entire character string (along with any character strings to the
left of it) is treated as a comment. If you include comments
(hyphenated or not), you must include the separating hyphen
between the comment and the file-system ID.
For example, take the following two assignment-name formats:
my-comment-vsam-myfile
In this example, my-comment is the comment, vsam is the
file-system ID, and myfile is the system file or environment
variable name.
my-comment-am-myfile
In this example, my-comment-am is the comment, and myfile is the
system file or environment variable name.
System file name / Environment variable name
If the assignment name is not specified in the literal form and
the environment variable matching the character string is found
at run time, the environment variable value is used to identify
the file system and the system file name. Otherwise, the
character string is used as the system file name.
Specifying alternate indexes-- The compiler normally assigns
default alternate index file names; however, you must override
the default assignment when:
- The file is not a local VSAM file and has different
alternate index file name specification rules. For example,
an SFS file where SFS requires an alternate index file name
to start with the base file name followed by ; followed by a
character string of your choice.
- The file already exists and has alternate index files with
names not corresponding to the default alternate index file
names that are assigned by the compiler. For example, a
remote OS/390 VSAM file or a local VSAM file create through
a different language, such as PL/I.
If specifying alternate index names, they must be specified in
the same order as the alternate record keys are specified in the
source program. You can omit alternate index names, but any
other alternate index names must correspond to the position in
the file definition. The following example shows how to specify
the first and third alternate index names:
base-file-name(first-index-file-name,,third-index-file-name)
In the above example, the compiler will assign a default file
name for the second alternate index file.
Alternate index file names are ignored for file systems that do
not require separate alternate index files, such as the STL file
system.
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