EDT Routines
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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VMS Help EDT Routines *Conan The Librarian (sorry for the slow response - running on an old VAX) |
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On OpenVMS operating systems, the EDT editor can be called from
a program written in any language that generates calls using the
OpenVMS Calling Standard.
You can set up your call to EDT so the program handles all the
editing work, or you can make EDT run interactively so you can
edit a file while the program is running.
| 1 - EDT$EDIT |
The EDT$EDIT routine invokes the EDT editor.
Format
EDT$EDIT in_file [,out_file] [,com_file] [,jou_file]
[,options] [,fileio] [,workio] [,xlate]
1.1 - Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword condition value. Most utility routines return a
condition value in R0. Condition values that this routine can
return are listed under Condition Values Returned.
1.2 - Arguments
in_file
OpenVMS usage:char_string
type: character-coded text string
access: read only
mechanism: by descriptor
File specification of the input file that EDT$EDIT is to edit.
The in_file argument is the address of a descriptor pointing
to this file specification. The string that you enter in this
calling sequence is passed to the FILEIO routine to open the
primary input file. This is the only required argument.
out_file
OpenVMS usage:char_string
type: character-coded text string
access: read only
mechanism: by descriptor
File specification of the output file that EDT$EDIT creates.
The out_file argument is the address of a descriptor pointing
to this file specification. The default is that the input file
specification is passed to the FILEIO routine to open the output
file for the EXIT command.
com_file
OpenVMS usage:char_string
type: character-coded text string
access: read only
mechanism: by descriptor
File specification of the startup command file to be executed
when EDT is invoked. The com_file argument is the address of a
descriptor pointing to this file specification. The com_file
string is passed to the FILEIO routine to open the command file.
The default is the same as that for EDT command file defaults.
jou_file
OpenVMS usage:char_string
type: character-coded text string
access: read only
mechanism: by descriptor
File specification of the journal file to be opened when EDT is
invoked. The jou_file argument is the address of a descriptor
pointing to this file specification. The jou_file string is
passed to the FILEIO routine to open the journal file. The
default is to use the same file name as in_file.
options
OpenVMS usage:mask_longword
type: aligned bit string
access: read only
mechanism: by reference
Bit vector specifying options for the edit operation. The options
argument is the address of an aligned bit string containing this
bit vector. Only bits <5:0> are currently defined; all others
must be 0. The default options have all bits set to 0. This is
the same as the default setting when you invoke EDT to edit a
file from DCL.
Symbols and their descriptions follow:
Symbol Description
EDT$M_RECOVER If set, bit <0> causes EDT to read the journal
file and execute the commands in it, except for
the EXIT or QUIT commands, which are ignored.
After the journal file commands are processed,
editing continues normally. If bit <0> is set,
the FILEIO routine is asked to open the journal
file for both input and output; otherwise FILEIO
is asked only to open the journal file for
output. Bit <0> corresponds to the /RECOVER
qualifier on the EDT command line.
EDT$M_COMMAND If set, bit <1> causes EDT to signal if the
startup command file cannot be opened. When
bit <1> is 0, EDT intercepts the signal
from the FILEIO routine indicating that the
startup command file could not be opened.
Then, EDT proceeds with the editing session
without reading any startup command file.
If no command file name is supplied with
the call to the EDT$EDIT routine, EDT tries
to open SYS$LIBRARY:EDTSYS.EDT or, if that
fails, EDTINI.EDT. Bit <1> corresponds to the
/COMMAND qualifier on the EDT command line. If
EDT$M_NOCOMMAND (bit <4>) is set, bit <1> is
overridden because bit <4> prevents EDT from
trying to open a command file.
EDT$M_ If set, bit <2> prevents EDT from opening
NOJOURNAL the journal file. Bit <2> corresponds to the
/NOJOURNAL or /READ_ONLY qualifier on the EDT
command line.
EDT$M_NOOUTPUT If set, bit <3> prevents EDT from using the
input file name as the default output file name.
Bit <3> corresponds to the /NOOUTPUT or /READ_
ONLY qualifier on the EDT command line.
EDT$M_ If set, bit <4> prevents EDT from opening a
NOCOMMAND startup command file. Bit <4> corresponds to the
/NOCOMMAND qualifier on the EDT command line.
EDT$M_NOCREATE If set, bit <5> causes EDT to return to
the caller if the input file is not found.
The status returned is the error code EDT$_
INPFILNEX.
fileio
OpenVMS usage:vector_longword_unsigned
type: bound procedure value
access: function call
mechanism: by reference
User-supplied routine called by EDT to perform file I/O
functions. The fileio argument is the address of a bound
procedure value containing the user-supplied routine. When you
do not need to intercept any file I/O, either use the entry point
EDT$FILEIO for this argument or omit it. When you only need to
intercept some amount of file I/O, call the EDT$FILEIO routine
for the other cases.
To avoid confusion, note that EDT$FILEIO is a routine provided by
EDT whereas FILEIO is a routine that you provide.
In order to accommodate routines written in high-level languages
that do up-level addressing, this argument must have a data type
of BPV (bound procedure value). BPV is a two-longword entity
in which the first longword contains the address of a procedure
value and the second longword is the environment value. When the
bound procedure is called, EDT loads the second longword into R1.
If you use EDT$FILEIO for this argument, set the second longword
to <0>. You can pass a <0> for the argument, and EDT will set up
EDT$FILEIO as the default and set the environment word to 0.
workio
OpenVMS usage:vector_longword_unsigned
type: bound procedure value
access: function call
mechanism: by reference
User-supplied routine called by EDT to perform I/O between the
work file and EDT. The workio argument is the address of a bound
procedure value containing the user-supplied routine. Work file
records are addressed only by number and are always 512 bytes
long. If you do not need to intercept work file I/O, you can
either use the entry point EDT$WORKIO for this argument or omit
it.
In order to accommodate routines written in high-level languages
that do up-level addressing, this argument must have a data type
of BPV (bound procedure value). This means that EDT loads R1 with
the second longword addressed before calling it. If EDT$WORKIO
is used for this argument, set the second longword to 0. You can
pass a 0 for this argument, and EDT will set up EDT$WORKIO as the
default and set the environment word to 0.
xlate
OpenVMS usage:vector_longword_unsigned
type: bound procedure value
access: function call
mechanism: by reference
User-supplied routine that EDT calls when it encounters the
nokeypad command XLATE. The xlate argument is the address of a
bound procedure value containing the user-supplied routine. The
XLATE routine allows you to gain control of your EDT session. If
you do not need control of EDT during the editing session, you
can either use the entry point EDT$XLATE for this argument or
omit it.
In order to accommodate routines written in high-level languages
that do up-level addressing, this argument must have a data type
of BPV (bound procedure value). This means that EDT loads R1 with
the second longword addressed before calling it. If EDT$XLATE
is used for this argument, set the second longword to 0. You can
pass a 0 for this argument, and EDT will set up EDT$XLATE as the
default and set the environment word to 0.
1.3 - Description
If the EDT session is terminated by EXIT or QUIT, the status will
be a successful value (bit <0> = 1). If the session is terminated
because the file was not found and if the /NOCREATE qualifier
was in effect, the failure code EDT$_INPFILNEX is returned. In an
unsuccessful termination caused by an EDT error, a failure code
corresponding to that error is returned. Each error status from
the FILEIO and WORKIO routines is explained separately.
Three of the arguments to the EDT$EDIT routine, fileio, workio,
and xlate are the entry point names of user-supplied routines.
1.4 - Condition Values Returned
SS$_NORMAL Normal successful completion.
EDT$_INPFILNEX /NOCREATE specified and input file does not
exist.
This routine also returns any condition values returned by user-
supplied routines.
| 2 - FILEIO |
The user-supplied FILEIO routine performs file I/O functions.
Call it by specifying it as an argument in the EDT$EDIT routine.
It cannot be called independently.
Format
FILEIO code ,stream ,record ,rhb
2.1 - Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
A status code that your FILEIO routine returns to EDT$EDIT. The
fileio argument is a longword containing the status code. The
only failure code that is normally returned is RMS$_EOF from
a GET call. All other OpenVMS RMS errors are signaled, not
returned. The RMS signal should include the file name and both
longwords of the RMS status. Any errors detected with the FILEIO
routine can be indicated by setting status to an error code.
That special error code will be returned to the program by the
EDT$EDIT routine. There is a special status value EDT$_NONSTDFIL
for nonstandard file opening.
Condition values are returned in R0.
2.2 - Arguments
code
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
A code from EDT that specifies what function the FILEIO routine
is to perform. The code argument is the address of a longword
integer containing this code. Following are the valid function
codes:
Function Code Description
EDT$K_OPEN_INPUT The record argument names a file to be
opened for input. The rhb argument is the
default file name.
EDT$K_OPEN_OUTPUT_SEQ The record argument names a file to be
opened for output as a sequenced file. The
rhb argument is the default file name.
EDT$K_OPEN_OUTPUT_ The record argument names a file to be
NOSEQ opened for output. The rhb argument is the
default file name.
EDT$K_OPEN_IN_OUT The record argument names a file to be
opened for both input and output. The rhb
argument is the default file name.
EDT$K_GET The record argument is to be filled with
data from the next record of the file.
If the file has record prefixes, rhb is
filled with the record prefix. If the
file has no record prefixes, rhb is not
written. When you attempt to read past the
end of file, status is set to RMS$_EOF.
EDT$K_PUT The data in the record argument is to be
written to the file as its next record. If
the file has record prefixes, the record
prefix is taken from the rhb argument. For
a file opened for both input and output,
EDT$K_PUT is valid only at the end of the
file, indicating that the record is to be
appended to the file.
EDT$K_CLOSE_DEL The file is to be closed and then deleted.
The record and rhb arguments are not used
in the call.
EDT$K_CLOSE The file is to be closed. The record and
rhb arguments are not used in the call.
stream
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
A code from EDT that indicates which file is being used. The
stream argument is the address of a longword integer containing
the code. Following are the valid codes:
Function Code Description
EDT$K_COMMAND_ The command file.
FILE
EDT$K_INPUT_FILE The primary input file.
EDT$K_INCLUDE_ The secondary input file. Such a file is
FILE opened in response to an INCLUDE command. It
is closed when the INCLUDE command is complete
and will be reused for subsequent INCLUDE
commands.
EDT$K_JOURNAL_ The journal file. If bit 0 of the options is
FILE set, it is opened for both input and output
and is read completely. Otherwise, it is
opened for output only. After it is read
or opened for output only, it is used for
writing. On a successful termination of the
editing session, the journal file is closed
and deleted. EXIT/SAVE and QUIT/SAVE close the
journal file without deleting it.
EDT$K_OUTPUT_FILE The primary output file. It is not opened
until you enter the EXIT command.
EDT$K_WRITE_FILE The secondary output file. Such a file is
opened in response to a WRITE or PRINT
command. It is closed when the command is
complete and will be reused for subsequent
WRITE or PRINT commands.
record
OpenVMS usage:char_string
type: character-coded text string
access: modify
mechanism: by descriptor
Text record passed by descriptor from EDT to the user-supplied
FILEIO routine; the code argument determines how the record
argument is used. The record argument is the address of a
descriptor pointing to this argument. When the code argument
starts with EDT$K_OPEN, the record is a file name. When the code
argument is EDT$K_GET, the record is a place to store the record
that was read from the file. For code argument EDT$K_PUT, the
record is a place to find the record to be written to the file.
This argument is not used if the code argument starts with EDT$K_
CLOSE.
Note that for EDT$K_GET, EDT uses a dynamic or varying string
descriptor; otherwise, EDT has no way of knowing the length of
the record being read. EDT uses only string descriptors that can
be handled by the Run-Time Library routine STR$COPY_DX.
rhb
OpenVMS usage:char_string
type: character-coded text string
access: modify
mechanism: by descriptor
Text record passed by descriptor from EDT to the user-supplied
FILEIO routine; the code argument determines how the rhb argument
is used. When the code argument starts with EDT$K_OPEN, the rhb
argument is the default file name. When the code is EDT$K_GET
and the file has record prefixes, the prefixes are put in this
argument. When the code is EDT$K_PUT and the file has record
prefixes, the prefixes are taken from this argument. Like the
record argument, EDT uses a dynamic or varying string descriptor
for EDT$K_GET and uses only string descriptors that can be
handled by the Run-Time Library routine STR$COPY_DX.
2.3 - Description
If you do not need to intercept any file I/O, you can use the
entry point EDT$FILEIO for this argument or you can omit it. If
you need to intercept only some file I/O, call the EDT$FILEIO
routine for the other cases.
When you use EDT$FILEIO as a value for the fileio argument, files
are opened as follows:
o The record argument is always the RMS file name.
o The rhb argument is always the RMS default file name.
o There is no related name for the input file.
o The related name for the output file is the input file with
OFP (output file parse). EDT passes the input file name, the
output file name, or the name from the EXIT command in the
record argument.
o The related name for the journal file is the input file name
with the OFP RMS bit set.
o The related name for the INCLUDE file is the input file name
with the OFP set. This is unusual because the file is being
opened for input.
EDT contains support for VFC files. Normally, EDT will zero the
length of the RHB field if the file is not a VFC file. However,
when the user supplies the FILEIO routines, they are responsible
for performing this operation.
EDT checks for a VFC file with the following algorithm:
IF FAB$B_RFM = FAB$C_VFC
AND FAB$B_RAT <> FAB$M_PRN
THEN
VFC file
ELSE
not VFC file, zero out RHB descriptor length field.
2.4 - Condition Values Returned
SS$_NORMAL Normal successful completion.
EDT$_NONSTDFIL File is not in standard text format.
RMS$_EOF End of file on a GET.
| 3 - WORKIO |
The user-supplied WORKIO routine is called by EDT when it
needs temporary storage for the file being edited. Call it by
specifying it as an argument in the EDT$EDIT routine. It cannot
be called independently.
Format
WORKIO code ,recordno ,record
3.1 - Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by immediate value
Longword value returned as a status code. It is generally a
success code, because all OpenVMS RMS errors should be signaled.
The signal should include the file name and both longwords of the
RMS status. Any errors detected within work I/O can be indicated
by setting status to an error code, which will be returned by the
EDT$EDIT routine.
The condition value is returned in R0.
3.2 - Arguments
code
OpenVMS usage:longword_unsigned
type: longword (unsigned)
access: read only
mechanism: by reference
A code from EDT that specifies the operation to be performed.
The code argument is the address of a longword integer containing
this argument. The valid function codes are as follows:
Function Code Description
EDT$K_OPEN_IN_ Open the work file for both input and output.
OUT Neither the record nor recordno argument is
used.
EDT$K_GET Read a record. The recordno argument is the
number of the record to be read. The record
argument gives the location where the record is
to be stored.
EDT$K_PUT Write a record. The recordno argument is the
number of the record to be written. The record
argument tells the location of the record to be
written.
EDT$K_CLOSE_DEL Close the work file. After a successful close,
the file is deleted. Neither the record nor
recordno argument is used.
recordno
OpenVMS usage:longword_signed
type: longword integer (signed)
access: read only
mechanism: by reference
Number of the record to be read or written. The recordno argument
is the address of a longword integer containing this argument.
EDT always writes a record before reading that record. This
argument is not used for open or close calls.
record
OpenVMS usage:char_string
type: character string
access: modify
mechanism: by descriptor
Location of the record to be read or written. This argument
always refers to a 512-byte string during GET and PUT calls.
This argument is not used for open or close calls.
3.3 - Description
Work file records are addressed only by number and are always 512
bytes long. If you do not need to intercept work file I/O, you
can use the entry point EDT$WORKIO for this argument or you can
omit it.
3.4 - Condition Value Returned
SS$_NORMAL Normal successful completion.
| 4 - XLATE |
The user-supplied XLATE routine is called by EDT when it
encounters the nokeypad command XLATE. You cause it to be called
by specifying it as an argument in the EDT$EDIT routine. It
cannot be called independently.
Format
XLATE string
4.1 - Returns
OpenVMS usage:cond_value
type: longword (unsigned)
access: write only
mechanism: by value
Longword value returned as a status code. It is generally a
success code. If the XLATE routine cannot process the passed
string for some reason, it sets status to an error code.
Returning an error code from the XLATE routine aborts the current
key execution and displays the appropriate error message.
The condition value is returned in R0.
4.2 - Argument
string
OpenVMS usage:char_string
type: character-coded text string
access: modify
mechanism: by descriptor
Text string passed to the nokeypad command XLATE. You can use the
nokeypad command XLATE by defining a key to include the following
command in its definition:
XLATEtext^Z
The text is passed by the string argument. The string argument
can be handled by the Run-Time Library routine STR$COPY_DX.
This argument is also a text string returned to EDT. The string
is made up of nokeypad commands that EDT is to execute.
4.3 - Description
The nokeypad command XLATE allows you to gain control of the
EDT session. (See the OpenVMS EDT Reference Manual for more
information about the XLATE command.) If you do not need to gain
control of EDT during the editing session, you can use the entry
point EDT$XLATE for this argument or you can omit it.
4.4 - Condition Value Returned
SS$_NORMAL Normal successful completion.
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