There are many extensions available to SDA. Most of these are not documented. Some may be supplied with third-party applications. To determine which extensions are available, use the DIRECTORY command. The portion of the file name before the dollar sign ($) is the command. To get help on each extension, when available, use one of the following methods.

Enter the name of the extension - some extensions will automatically display help information if no subcommands are provided.
Enter the name of the extension followed by the command HELP.
For the pthread extension, the process context must first be set to a multi-threaded process before entering the PTHREAD HELP command.

$ directory sys$share:*$sda.exe

Directory SYS$COMMON:[SYSLIB]

CLUE$SDA.EXE;1
CNX$SDA.EXE;1
DECDTM$SDA.EXE;1
DKLOG$SDA.EXE;1
EXC$SDA.EXE;1
FC$SDA.EXE;1
FLT$SDA.EXE;1
IO$SDA.EXE;1
IPC$SDA.EXE;1
ISCSI$SDA.EXE;1
LAN$SDA.EXE;1
LCK$SDA.EXE;1
LNM$SDA.EXE;1
MTX$SDA.EXE;1
OCLA$SDA.EXE;1
PCS$SDA.EXE;1
PE$SDA.EXE;1
PKM$SDA.EXE;1
PRF$SDA.EXE;1
PSH$SDA.EXE;1
PTHREAD$SDA.EXE;1
PWIP$SDA.EXE;1
RMS$SDA.EXE;1
SHAD$SDA.EXE;1
SPL$SDA.EXE;1
TCPIP$SDA.EXE;1
TQE$SDA.EXE;1
TR$SDA.EXE;1
USB$SDA.EXE;1
XFC$SDA.EXE;1
XX$SDA.EXE;1

Total of 31 files.


There may also be some extensions residing in different directories and pointed to by logical names. Issueing the command SHOW LOGICAL *$SDA will show those logical names.

Note: Unlike the traditional thinking of SDA being a look only access to the system; with some of these extensions, it is possible that SDA is making changes to the system. Use with extreme caution.