User`s guide

CREATE
sure that there is enough unused space on the volume for the size you specify
(use the DIRECTORY/FULL command to do this).
Procedure for Extending a File
The following example illustrates the procedure for extending a file with the
CREATE command. In this example, BUILD.MAC is extended by 20 blocks.
1. A DIRECTORY/FULL command determines whether there is available space
adjacent to BUILD.MAC:
.DIRECTORY/FULL DU1:
09-FEB-90
MYPROG.MAC 36P 19-JAN-90 TM .MAC 25 27-JAN-90
VTMAC .MAC 7 19-JAN-90 MYPRO2.MAC 41 19-JAN-90
< UNUSED > 25 TEST .MAC 67P 19-JAN-90
LELA .LBM 1 09-FEB-90 BUILD .MAC 80 19-JAN-90
< UNUSED > 604
7 Files, 257 Blocks
629 Free blocks
2. The CREATE command extends BUILD.MAC by 20 blocks:
.CREATE DU1:BUILD.MAC/EXTENSION:20
/START:value
Specifies the starting block number of the file you are creating. The value
argument specifies a decimal block number. If you do not use /START, RT–11
uses the first available space on the volume.
Procedure for Creating a File with CREATE
The following example illustrates the procedure for creating a file with the
CREATE command. In this example, SWAP.SYS is restored after having been
deleted.
Note that you can restore a deleted file only if it has not been written over by
a new file. So, if you should ever have to restore a deleted file, you should do it
before you create any new files.
1. A DIRECTORY/DELETED command establishes the starting block numbers
of the deleted files on DU1:
.DIRECTORY/DELETED DU1:
09-FEB-90
SWAP .SYS 28 19-JAN-90 117 EMPTY.FIL 179 31-JAN-90 315
0 Files, 0 Blocks
204 Free blocks
2. The CREATE command restores SWAP.SYS, starting at block 117, and the
/ALLOCATE:size option allocates 28 blocks:
.CREATE DU1:SWAP.SYS/START:117/ALLOCATE:28
See the RT–11 Volume and File Formats Manual for a detailed description of the
RT–11 file structure.
RT–11 Command Descriptions 59