2. Invalid routine name in SVC 202 parameter list. If the routine named in the SVC 202 parameter list is invalid or cannot be fOURd, DMSITS handles the situation in the same way as it handles an error
return from a legitimate SVC routine. The error code is -3.
3. Invalid SVC 203 code. If an invalid code follows SVC 203 inline,
then an error message is displayed, and the abend routine is called
to terminate execution. SEARCH HIERARCHY FOR SVC 202 When a program issues SVC 202, passing a routine or command name in the
parameter list, then DMSITS must be searched for the specified routine
or command. (In the case of SVC 203 with a zero in the table entry for
the specified index, the same logic must be applied.)
The search algorithm is as follows:
A check is made to see if there is a routine with
name currently occupying the system transient area.
case, then control is transferred there.
the specified
If this is the
2. The system function name table is searched, to see if a command by this name is a nucleus-resident command. If the search is
successful, control goes to the specified nucleus routine. 3. A search is then made for a disk file with the specified name as
the filename, and MODULE as the filetype. The search is made in
the standard disk search order. If this search is successful, then
the specified module is loaded (via the LOADeOD command), and
control passes to the storage location now occupied by the command.
4. If all searches so far have failed, then DMSINA (ABBREV) is called,
to see if the specified routine name is a valid system abbreviation
for a system command or function. User-defined abbreviations and
synonyms are also checked. If this search is successful. then
steps 2 through 4 are repeated with the full function name.
5. If all searches fail, then an error code of -3 is issued. When a command is entered from the terminal, DeSINT processes the
command line, and calls the scan routine to convert it into a parameter
list consisting of eight-byte entries. The following search is
1. DMSINT searches for a disk file whose filename is the command name,
and whose filetype is EXEC. If this search is successful, EXEC is
invoked to process the EXEC file.
If not found, the command name is considered to be an abbreviation
and the appropriate tables are examined. If found, the abbreviation
is replaced by its full equivalent and the search for an EXEC file
is repeated. Part 3. Conversational Monitor System (CMS) 259
2. If there is no EXEC file, DMSINT executes SVC 202, passing the
scanned parameter list, with the command name in the first eight
bytes. DMSITS will perfor. the search described for SVC 202 in an
effort to execute the command. If DMSITS returns to DMSINT with a return code of -3, indicating
that the search was unsuccessful, then DMSINT uses the CP DIAGNOSE facility to attempt to execute the command as a CP command.
4. If all of these searches fail, then DMSINT displays the error
message UNKNOWN CP/CMS COMMAND. See Figure 28 for a description of this search for a command name. 260 IBM VM/370 System programmer's Guide
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