Apr il 1, 1981
54.2 IBM VM/370 User's Guide

March 30, 1979
Filemode 2: Filemode 2 is essentially the same, for the purposes of reading-and writing files, as filemode 1. Usually a filemode of 2 is
assianed to files that are shared by users who link to a common disk, likeJthe system disk. Since you can access a disk and specify which
files on that disk you want to access, files with a filemode of 2
provide a convenient subset of all files on a disk. For example, if you
issue the command:
access 489 e/a * * e2
you can only read files with a filemode of 2 on the disk at virtual
address 489. J: Files with a filemode of 3 are erased after they are read.
If you create a file with a filemode of 3 and then request that it be
printed, the file is printed, and then erased. You can use this file.ode
if you write a program or EXEC procedure that creates files that you do
not want to maintain copies of on your virtual disks. You can create the
file,-print it, and not have to worry about erasing it later.
The language processors and some CMS commands create work files and
give these work files a file mode of 3.
Note: A filemode of 3 should not be used with EXECs. Depending on what commands are issued within it, an EXEC with a filemode of 3 may be
erased before it completes execution. Files with a filemode of 4 are in as simulated data set
format. These files are created by as macros in running in CMS. You specify that a file created by a program to have OS simulated data set format by specifying a filemode of 4 when you issue
the FILEDEF command for output file. you QO not specify a filemode of 4, the output file is created in CMS format. You can find more details about as simulated data sets in "Section 8.
Developing as programs Under CMS." !gte: There are no filemode numbers reserved for DOS or VSAM data sets,
since CMS does not simulate these file organizations.
Filemode 5: This filemode number is the same, for purposes of reading as filemode 1. You can assign a filemode of 5 to files that
you want to maintain as logical groups, so that you can manipulate thea in groups. For example, you can reserve the filemode of 5 for all files
that you are retaining for a certain period of time; then, when you want
to erase them, you could issue the command:
erase * * as You can assign filemode numbers when you use the following commands: COPYFILE: You can assign a filemode number when you create a new file wIth-the COPYFILE command. To change only the filemode number of an
existing file, you must use the REPLACE option. For exaaple:
copy file test module a1 = = a2 (replace
changes the filemode number of the file TEST MODULE A from 1 to 2.
Section 4. The CMS File System 55