After allocating an external file, you can use the fileref
or ddname of the file as a convenient way of referring to that file
in any subsequent SAS language statement or command.
Note: The first time the ddname
of an external file is used in a SAS statement or procedure, SAS assigns
it as a fileref for the external file. Therefore, any information
provided here about filerefs also applies to the ddnames of external
files. For more information, see
Summary Table of SAS Software Files and Reserved z/OS ddnames for a list of files and ddnames that have special meanings
to SAS the operating environment.
In the following example,
the FILENAME statement associates the fileref REPORT with the sequential
data set MYID.NEWDATA. The FILE statement later uses the fileref rather
than the data set name to refer to the data set.
filename report 'myid.newdata' disp=old;
data _null_;
file report;
put ...;
run;
Here is a similar example
in which a JCL DD statement associates the ddname IN with a member
of a partitioned data set. The INFILE statement later uses the ddname
rather than the data set name and member name to refer to the PDS
member.
//IN DD DSN=MYID.NEWDATA(TRIAL1),DISP=SHR
//SYSIN DD *
data out;
infile in;
input ...;
run;
When referring to a
member of a PDS or a PDSE, you also have the option of specifying
only the data set name in the FILENAME statement (or FILENAME function)
or in the DD statement. Then, in subsequent references, you specify
the member name with the fileref. For example:
//IN DD DSN=MYID.NEWDATA,DISP=SHR
//SYSIN DD *
data out;
infile in(trial1);
input ...;
run;
If an external data
set is not cataloged, you must also provide the volume serial number.
If SAS requires that a file must be identified only by its physical
name, that name must represent a cataloged data set or HFS file. Temporary
data sets are not cataloged, and SAS cannot locate temporary data
sets if you provide only a physical name. For information about other
options that you can specify, see
FILENAME Statement: z/OS.Note: If you are using files in
the USS file system, SAS makes no distinction between the
z/OS file
system (zFS) and the Hierarchical File System (HFS).