Migration

Execution: Migrate Files

Special Topic: Migrating Files with Short Extensions on PC Operating Environments

In Versions 7 and 8, the SHORTFILEEXT option creates a file with a shortened, three-character extension on PC operating environments only. This feature is necessary for operating environments that use a FAT (file allocation table) file system, which is also referred to as "8.3" because a file name can include up to eight characters and a file extension can include up to three characters.

Determining Whether a Library Contains Short-Extension Files

These files should only be found on PC operating environments. They are unusable by SAS on other environments.

Version 6 files: Although they all have three-character extensions, Version 6 files are not affected by this issue. You can distinguish Version 6 files because their extensions do not contain the number 7. See the PROC MIGRATE Calculator for migration instructions.

Version 7 and 8 files: Below is a list of the short and standard extensions for Version 7 and 8 files. To determine whether a library contains files with short extensions, look at the filenames in the SAS Explorer or use the file management tools of your operating environment.

Memtype	Short Extension	Standard Extension
ACCESS	sa7	sas7bacs
AUDIT	st7	sas7baud
CATALOG	sc7	sas7bcat
DATA	sd7	sas7bdat
DMDB	s7m	sas7bdmd
FDB	sf7	sas7bfdb
INDEX	si7	sas7bndx
ITEMSTOR	sr7	sas7bitm
MDDB	sm7	sas7bmdb
PROGRAM	ss7	sas7bpgm
PUTILITY	sp7	sas7bput
UTILITY	su7	sas7butl
VIEW	sv7	sas7bvew

SAS®9 Compatibility with Short-Extension Files

SAS 9.0 supports the SHORTFILEEXT option, although it is not documented. If you use the option, you have read and write access to your existing short-extension files.
SAS 9.1 and 9.1.2 do not support any access to short-extension files.
SAS 9.1.3 supports the SHORTFILEEXT option for read-only (input) access.

Deciding Whether to Migrate

If the above compatibility is adequate for your short-extension files, use the Compatibility Calculator to be certain that you have no other reason to migrate.

If the above compatibility is not adequate, then you have two choices:

To migrate the files to SAS®9 format, use the instructions in the following sections for migrating to SAS 9.1.3 or to SAS 9.1 or SAS 9.1.2.
If you want to keep the files in SAS 8.2 format, you can use one of the two methods in the section below for SAS 9.1 and SAS 9.1.2 to simply change the short file extensions to standard file extensions and omit the PROC MIGRATE step. However, because the files remain in SAS 8.2 format, you are still subject to cross-release compatibility. Therefore, before you make this decision, use the Compatibility Calculator to be certain that you have no other reason to migrate.

Migrating Files to SAS 9.1.3

Migrate the library to SAS 9.1.3 by using PROC MIGRATE. You must specify the SHORTFILEEXT option on the LIBNAME statement for the source library. The files are written to the SAS 9.1.3 library with standard extensions. See the PROC MIGRATE Calculator to learn whether you can use PROC MIGRATE. If so, then remember to specify SHORTFILEEXT as noted above. If you can't use PROC MIGRATE, then follow the instructions given below for SAS 9.1 and 9.1.2.

Here is an example that uses PROC MIGRATE in SAS 9.1.3. A library named MYLIB contains two files with short extensions: a data set named mydata.sd7 and a catalog named mycat.sc7. The following code migrates the library to SAS®9:

libname mylib v8 'path-name' shortfileext;
libname newlib v9 'another-path-name';

proc migrate in=mylib out=newlib;
run;

After migration, the target library NEWLIB contains two files with standard extensions: a data set named mydata.sas7bdat and a catalog named mycat.sas7bcat.

If your library also contains standard-extension files, then perform an additional migration without the SHORTFILEEXT option on the LIBNAME statement to migrate those files. In this case, take care with filenames. In the target library, all files will have a standard extension. If, in the source library, a short-extension file and a standard-extension file have the same name, then in the target library, the second one will fail to migrate because a name and member of the same type already exists.

Migrating Files to SAS 9.1 or SAS 9.1.2

The SHORTFILEEXT option is not supported in SAS 9.1 or SAS 9.1.2. Instead, you can use PROC COPY in Version 8 to copy the short file extensions to standard file extensions before migrating your files to SAS®9. See the PROC MIGRATE Calculator for the remainder of your migration instructions.

As an alternative to PROC COPY, if you are comfortable using operating environment commands or file management tools, you can manually change the file's extension to the standard extension shown in the table above. The contents of a short-extension file are completely identical to those of a standard-extension file. The use of operating system commands is not supported by SAS.

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