DIBIOL/DBL - Statements

Voor mogelijke I/O statements bij de diverse OPEN modes, zie onderaan.

#      -  12345#2     > 123
##     -  12345##2    > 12300


.eq(s)(u)., etc..

"ABC" .eq.  "ABCD"  > true
"ABC" .eqs. "ABCD"  > false
"ABC" .eqs. "ABC"   > true

intgr = -1
intgr .eq.  -1     > true
intgr .equ. -1     > false
intgr .equ. 255    > true


.(b)and., etc..

int1 = %b(1010)
int2 = %b(0110)

int1 .band. int2  >  0010                   int1 .and. int2  >  1
int1 .bor.  int2  >  1110                   int1 .or.  int2  >  1
int1 .bxor. int2  >  1100                   int1 .xor. int2  >  0
     .bnot. int1  >  1001                        .not. int1  >  0
     .bnot. int2  >  0101                        .not. int2  >  0

ACCEPT inputs a character (or key sequence) from a terminal. ANSI Escape
sequence processing is set by XCALL DBL$TTFLGS(1000). Use %RTERM after
the statement when accepting chars in an alpha field. Key definitions are listed
in the includefile "KEYDEFS" in library SYS$LIBRARY:DBLTEXT.TLB.

ACCEPT (ch,field{,label}{,WAIT{:seconds}})

keywords

ch is a numeric expression that evaluates to a channel
number as specified in a previous OPEN statement.

field is an alpha field, numeric field, or record which will
contain the character input from the terminal.

label is a statement label where control is to be transferred
when a CTRL/Z is detected.

WAIT:seconds
is an integer expression which specifies the number of
seconds to wait for terminal input before generating a
timeout error.

BEGIN-END

The BEGIN-END block is a sequence of statements preceded by BEGIN and
followed by END. A BEGIN-END block may be used wherever a statement is
valid.

BEGIN
statement
.
.
.
END

CALL

CALL transfers program control to an internal subroutine.

CALL label

CLEAR

CLEAR sets variables to zeros or spaces.

CLEAR field{,...}

CLOSE terminates the use of a channel by closing the associated file
and releasing both the I/O channel and the file buffer.

CLOSE ch{,ch...}

COMMON

COMMON defines the areas in memory where variable data is stored.
This data is to be shared between the main program and external
subroutines.

{|EXTERNAL|} COMMON {name}{,X}{,NOSUFFIX}
| GLOBAL |

DECR

DECR decreases a numeric field by 1.

DECR nvar

DELETE

DELETE eliminates a record from an indexed file.

DELETE (ch)

DETACH

DETACH is ignored by VAX DIBOL.

DETACH

DISPLAY

DISPLAY outputs characters to a device or file

DISPLAY (ch,|aexp|{<output field attributes>})
|nexp|

attributes

Output field attributes apply to fields specified in DISPLAY or
WRITES.

{field}<{POS:({l}{,c})}{,VIDEO:flags}{,ERASE:code}{,FORMAT:mask}>

POS

POS:(l,c) positions the cursor at the location specified by l and c. L
and c are integer expressions. l is the line number and c is the column
number.

VIDEO

VIDEO:flags specifies the terminal video attribute. Assigned codes are:

1 - BLINK
2 - BOLD
4 - REVERSE
8 - UNDERSCORE

ERASE

ERASE:area specifies the area of the screen to be erased after the
cursor is positioned. Assigned codes are:

1 - total screen
2 - cursor to end of screen
3 - all of line
4 - cursor to end of line

FORMAT

FORMAT:mask specifies a formatting mask to be used. assigned codes
are:

C - Any character
X - Digit
Z - Zero-suppressed digit
* - Check-protected digit
money - Floating money sign
minus - Negative sign if at beginning or end else dash
decpt - Decimal point
digsp - Digit separator

DO-UNTIL

DO-UNTIL repetitively executes a statement until a condition is true.

DO statement UNTIL condition

EXIT

EXIT terminates execution of a BEGIN-END block in a structured manner.

EXIT {label}

EXITLOOP

EXITLOOP allows a structured method of leaving a DO-UNTIL, WHILE, FOR, or
REPEAT loop.

EXITLOOP

EXTERNAL FUNCTION (zie FUNCTIONS)

EXTERNAL FUNCTION declares a function to be user-defined and to have a
specified data type.

EXTERNAL FUNCTION
name, t{.}
...

FIND (zie %RFA)

FIND locates a specified record in a disk file and makes it the "current"
record for a subsequent READS, WRITE, or DELETE operation.

FIND (ch{|{,mval}{,KEYNUM:iexp}{,MATCH:iexp}|}{,WAIT{:seconds}})
|{RFA:rfaddr} |

mval

mval is used to find a record in an indexed file or the record to use
in a FIND to a relative file.

KEYNUM

KEYNUM:iexp is an integer expression that specifies which key number is
to be used in a FIND from an indexed file.

MATCH

MATCH:iexp is an integer expression that determines the type of match
to use on this key lookup.

RFA

RFA:rfaddr is the alpha string containing the record file access value
that evaluates to the "record number" field.

WAIT

WAIT:seconds is an integer expression that specifies the number of
seconds to wait if a record locked condition occurs before generating a
timeout error.

FLUSH

FLUSH causes any pending disk writes to be completed on the specified
channel.

FLUSH ch

FOR

FOR repetitively executes a statement until n field is equal to final.

FOR nfield FROM initial THRU final {BY step} statement

FORMS

FORMS outputs device-dependent codes to effect forms control. These
codes are normally used by printers.

FORMS (ch,nexp)

Valid values for nexp:

1-255 Output specified number of line-feeds.
0 Output form-feed
-1 Output vertical tab character
-3 Output carriage-return character

FRETURN

FRETURN returns control to the calling program that executed the function.

FRETURN expression

FUNCTION

FUNCTION identifies a program as a function definition.

FUNCTION name {,%VAL}

GOTO

An unconditional GOTO transfers program control.

GOTO label

GOTO-Computed

A computed GOTO transfers program control based on the evaluation of
an expression.

GOTO (label{,...}), nexp

GROUP

GROUP defines a field within RECORD or COMMON and defines its subfields.

GROUP name, {n}{t}{s}{,X}
{subfield definition}
ENDGROUP

n is the dimensional field count. this can only be in the array
format:

(real array)([n{,...}])

t is the data type (A,D,I,P). the default is alpha (A).

s is the size of each data element.

RECORD
GROUP STATE, [50]A
NAME, A20
PEOPLE, D7
GROUP CAPITOL, A
NAME, A20
PEOPLE, D7

Access: STATE[1].NAME or STATE[1].CAPITOL.NAME

IF executes a statement if a condition is true.

IF condition statement

IF-THEN-ELSE

IF-THEN-ELSE executes 1 of 2 statements based on a condition.

IF condition THEN statement1 ELSE statement2

INCR

INCR increases a numeric field by 1.

INCR nfield

LITERAL (zie Argument/Field definitions)

LITERAL defines data literals that can be used in the Data or Procedure
Division.

| GLOBAL |
{|EXTERNAL|} LITERAL
| LOCAL |

name, t {*} {,value}
{n} %XTRNL (xxx)

LOCASE

LOCASE converts uppercase characters to corresponding lowercase
characters.

LOCASE afield

LPQUE

LPQUE queues a file to be printed by the printer spooler.

LPQUE(filespec{,LPNUM:exp}{,COPIES:nexp}{,FORM:exp}{,DELETE}{,ALIGN})

filespec

filespec is an alpha field containing the name of the file to be
printed.

LPNUM

LPNUM:exp is either a numeric or alpha expression that specifies the
printer. When using a numeric expression the result must match a symbol
DBL$LPx.

COPIES

COPIES:nexp is a numeric expression which specifies the number of copies
to print.

FORM

FORM:exp is either a numeric or alpha expression that specifies the type
or name of the form to be inserted into the printer before the file is
printed.

DELETE

DELETE deletes the file after all copies have been printed.

ALIGN

ALIGN queues the file in a "hold" state so that the operator can take
whatever action is necessary.

NEXTLOOP

NEXTLOOP causes the next iteration of the current loop.

NOP

NOP is the "null operation". It is used as a placeholder.

OFFERROR

OFFERROR disables trapping of run-time errors.

OFFERROR

ONERROR

ONERROR enables trapping of run-time errors which would otherwise
cause program termination.

ONERROR label

OPEN

OPEN associates a channel number with a device or with a file on a
device.
Voor mogelijke I/O statements bij de diverse OPEN modes, zie onderaan.

OPEN (ch, mode{:submode}, filespec {,ALLOC:nexp}
{,BKTSIZ:nexp}
{,BLKSIZ:nexp}
{,BUFNUM:nexp}
{,BUFSIZ:nexp}
{,CONTIG:nexp}
{,DEQ:nexp}
{,FDL:fdlstr}
{,KEY:(keylist)}
{,NUMREC:nexp})
{,PROTECT:astr}
{,RECSIZ:nexp}
{,RECTYPE:nexp}
{,SHARE:nexp}

Modes

Valid OPEN modes Valid OPEN sub-modes

I Input S Sequential
O Output R Relative
U Update I Indexed
A Append P Print
B Block
* Wildcard

The combinations indicated by the * are valid:

Submode
S R I P B *
Mode +-------------------------------+
I | * * * * * |
O | * * * * * |
U | * * * * * |
A | * * * * * * |
+-------------------------------+

ALLOC

ALLOC:nexp is a numeric expression that specifies the initial or
additional file allocation with dexp specifying the number of blocks to
be initially allocated or added to a file.

BKTSIZ

BKTSIZ:nexp is a numeric expression that specifies the bucketsize in
blocks.

BLKSIZ

BLKSIZ:nexp is a numeric expression that specifies the block size
(bytes) of magnetic tape.

BUFNUM

BUFNUM:nexp is a numeric expression that specifies the number of
process local I/O buffers to allocate.

BUFSIZ

BUFSIZ:nexp is a numeric expression that specifies the size of the
transfer buffer in blocks for this channel.

RECSIZ

RECSIZ:nexp is a numeric expression that specifies the length (bytes)
of the records in the file.

CONTIG

CONTIG:nexp is a numeric expression that specifies the desired
contiguity of the file.

DEQ

DEQ:nexp is a numeric expression that specifies the default number of
the blocks to add when a disk file is automatically extended.

PROTECT

PROTECT:astr is an alpha expression that specifies a file protection
string.

RECTYPE

RECTYPE:nexp specifies the type of records that will be written to the
file.

SHARE:nexp is a numeric expression that specifies the type of file
access allowed to this file by other programs or channels.

FDL

FDL:fdlstr is an alpha expression which specifies a File Description
Language (FDL) string or file specification containing an FDL
description.

NUMREC

NUMREC:nexp is a numeric expression that specifies the number of
logical records in lengths as defined by RECSIZ that is to be used as
the initial allocation of a file, or to be added to an existing file.

KEY

KEY:(keylist) represents a list of keys which describe the primary and
alternate keys for an indexed file.

The format for a keylist item is:

(SEG:(POS:SIZE{,TYPE:ttt}{,ATTR:aaa}){,TYPE:TTT}{,ATTR:AAA})

(POS:SIZE{,TYPE:TTT}{,ATTR:AAA})

SEG indicates segment-specific information to the compiler.

aaa indicates segment-specific attributes
ttt indicates the segment type
AAA indicates the "whole key" attributes
TTT indicates the "whole key" type

PROC-END (Zie .MAIN, .PROC en .END)

PROC-END identifies the beginning and ending of the Procedure
Division.

PROC {dliteral}
statement
.
.
.
{END}

READ-Relative-file (zie %RFA)

READ inputs a record from a relative file.

READ (ch,record|,nexp |{,WAIT{:seconds}})
|,RFA:rfaddr|

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

nexp

nexp is a numeric expression that specifies the sequence number of the
record to be read.

WAIT

WAIT:seconds is a numeric expression that specifies the number of
seconds to wait if a record locked condition occurs.

RFA

RFA:rfaddr is an alpha string containing the record file access value
that evaluates to the "record number" field.

READ-Indexed-file (zie %RFA)

READ inputs a record from an indexed file.

READ (ch,record,|keyfld{,KEYNUM:nexp}{MATCH:nexp}|{,WAIT{:seconds}})
|RFA:rfaddr |

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

keyfld

keyfld is an alpha field or record that identifies the record to be read.

WAIT

WAIT:seconds is a numeric expression that specifies the number of
seconds to wait if a record locked condition occurs.

MATCH

MATCH:nexp is a numeric expression that determines the type of match to
use on this key lookup.

KEYNUM

KEYNUM:nexp is a numeric expression that specifies which key of
reference is to be used.

RFA

RFA:rfaddr is an alpha string containing the record file access value
that evaluates to the "record number" field.

READ-Sequential-File (zie %RFA)

Read inputs a record from a sequential file by RFA.

READ (ch,record,RFA:rfaddr)

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

RFA

RFA:rfaddr is an alpha string containing the record file access value
that evaluates to the "record number" field.

READS

READS inputs the next available record in sequence from a file, or
requests input from a terminal.

READS (ch,record{<input field attributes>}{,label}{,WAIT{:seconds})

WAIT

WAIT:seconds is a numeric expression which specifies the number of
seconds to wait if a record locked condition or to wait for terminal
input before generating a timeout error.

attributes

Input field attributes affect how the field is input.

POS

POS:(l,c) positions the cursor at the location specified by l and c. l
is the line number and c is the column number.

VIDEO

VIDEO:vflags enables various terminal video attributes. These
attributes (codes) may be added together to enable multiple attributes.
Codes assigned are:

1 - BLINK
2 - BOLD
4 - REVERSE
8 - UNDERSCORE

ERASE

ERASE:code specifies the area of the screen to be erased after the
cursor is positioned. Codes are:

1 - All the screen
2 - Cursor to end of screen
3 - All of line
4 - Cursor to end of the line

EDIT

EDIT:mask specifies an edit mask to be used for verification of input.
mask is an alpha expression. Valid characters are:

C - Any character Y - Any alpha plus digit
P - Any printable character Space or 0 - DEFAULT string character
A - Alpha N - Period, dash, plus sign, decimal
U - Uppercase point, or numeric punctuation.
L - Lowercase
X - Digit

DEFAULT

DEFAULT:exp indicates the default value of the field if nothing input.

FLAGS

FLAGS:iexp enables/disables certain XCALL FLAGS settings. Codes may be
added together to enable multiple FLAGS settings.

1 = ECHO (enables ECHO)
2 = NOECHO (disables ECHO)
4 = AUTO (enables automatic termination)
8 = NOAUTO (disables automatic termination)
16 = UPCASE (specifies input is to be uppercased after entry)
32 = NOUPCASE (specifies input is not to be uppercased after
entry)
64 = TERMECHO (enables echo of READS terminator)
128 = NOTERMECHO
256 = TYPAHD (purges typeahead buffer before accepting input)
512 = NOTYPAHD

OFFSET

OFFSET:nexp indicates the beginning character position within DEFAULT
to start entering characters. If OFFSET is not specified, it defaults
to length of DEFAULT.

PROMPT

PROMPT:aexp indicates a prompt string (aexp) to be output to the
terminal before input is accepted.

RECORD

RECORD defines the areas of memory where variable data is stored.

RECORD {name}{,X}

REPEAT

REPEAT repetitively executes a statment until a condition occurs to divert
control out of that block.

REPEAT statement

RECV

RECV accepts a message which was sent by another program.

RECV (message,label{,size})

RETURN

RETURN transfers program control to the statement logically following
the most recently executed CALL or XCALL statement.

RETURN

SEND (zie ook %WAIT)

SEND transmits a message to another program.

SEND (message,program{,terminal})

SLEEP

SLEEP suspends program execution for a specified period of time.
Do not use in a DIBOL AST routine.

SLEEP seconds

STOP

STOP terminates program execution.

If STOP is followed by an alpha field, the current program is terminated
and a "chain" is performed to the program specified in the alpha field
(filespec). If the first character of the filespec is an '@', it indicates
that the filespec is a command file.

If STOP is followed by a numeric variable or expression, the current
program is terminated and the numeric value is returned to the
operating system as the program's exit status.

STORE

STORE adds a record to an indexed file.

STORE (ch,record)

SUBROUTINE

SUBROUTINE identifies a program as an external subroutine.

SUBROUTINE name

UNLOCK

UNLOCK clears the lock condition on a specified channel.

UNLOCK ch

UPCASE

UPCASE converts lowercase characters to corresponding uppercase
characters.

UPCASE afield

USING

USING conditionally executes one statement from a list of statements
based on the evaluation of an expression.

USING selection_value SELECT
({match-expression{,...}}), statement
.
.
.
ENDUSING

Match-expression

A match-expression takes one of the following forms:

Multiple match-expressions can be specified for each statement.
An empty match-expression list matches any selection-value.
No match will occur if the value to the left of THRU (low-value) is
greater than the value to the right of THRU (high-value).
The data types of the values within the match-expression must match
the data type of the selection-value.

Example

USING VAR SELECT
(M1),
RSLT = 5
(M4 THRU M9, M15, M20 THRU M30),
RSLT = 10
(),
BEGIN
DISPLAY (15,10,"NO MATCH",13)
CLEAR RSLT
END
ENDUSING

USING-RANGE

USING with a specified range conditionally executes one statement from a
list of statements based on the value of an expression.

USING sexp RANGE low THRU high SELECT
({mexp{,...}}), statement
.
.
.
ENDUSING

Match-expression

mexp is one or more match expressions in the following format:

compile-time-expression
cte THRU cte
.LT. cte
.LE. cte
.GT. cte
.GE. cte

Example

USING VAR RANGE 10 THRU 14 SELECT
(10), RSLT = 5
(11), RSLT = 10
(12), RSLT = 4
(13), RSLT = 17
(14), RSLT = 7
(%INRANGE), RSLT = 99
(%OUTRANGE), RSLT = 88
ENDUSING

WHILE

WHILE repetitively executes a statement as long as a condition is
true.

WHILE condition statement

WRITE-Relative-file (zie %RFA)

WRITE outputs a record into a specified position in a relative file.

WRITE (ch,record|,nexp |)
|,RFA:rfaddr|

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

nexp

nexp is a numeric expression that specifies the sequence number of the
record to be written.

RFA

RFA:rfaddr is an alpha string containing the record file access value or
"record number" field.

WRITE-Indexed-file

WRITE updates a record in an indexed file.

WRITE (ch,record)

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

WRITE-Sequential-file (zie %RFA)

WRITE updates a record in a sequential file.

WRITE (ch,record,RFA:rfaddr)

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

RFA

RFA:rfaddr is an alpha string containing the record file access value or
"record number" field.

WRITES

WRITES outputs a record to the next available position in a file.

WRITES (ch,record{<output attributes>})

ch is a numeric expression that evaluates to a channel number as
specified in a previous OPEN statement.

record

record is an alpha field or record which will contain the data.

Attributes (see DISPLAY)

WRITES output attributes add enhancements to the record. If the channel is
not opened to a terminal, the escape sequences are inserted in the file.

XCALL

XCALL transfers program control to an external program.

XCALL name {(arg{,...})}

%DESCR

%DESCR causes the argument to be passed by descriptor. This is the
default passing mechanism for VAX DIBOL.

XCALL subr (%DESCR(arg))

%REF

%REF causes the argument to be passed by reference.

XCALL subr (%REF(arg))

%VAL

%VAL causes the argument to be passed by value.

XCALL subr (%VAL(arg))

%XTRNL

%XTRNL causes the value of an externally-defined symbol to be passed.

|+|
|-||arg |
XCALL subr %XTRNL(arg{|*||dlit|})
|/|

XRETURN

XRETURN transfers program control to the statement logically following the
most recently executed XCALL statement.

XRETURN {status}



Parameter schema ACCEPT, FIND, READ en READS:

                         mval    KEYNUM     MATCH    WAIT    RFA
                        -----------------------------------------
         mval             -         X         X       X       0
                        -----------------------------------------
         KEYNUM           X         -         X       X       0
                        -----------------------------------------
         MATCH            X         X         -       X       0
                        -----------------------------------------
         WAIT             X         X         X       -       X
                        -----------------------------------------
         RFA              0         0         0       X       -
                        -----------------------------------------


I/O schema:

          Sequential     Relative       Block          Indexed        Terminal   Printer  
          I  O  U  A     I  O  U  A     I  O  U  A     I  O  U  A     I  O       O        
reads     x  x  x  x     x  x  x  x     x  x  x  x     x  x  x  x     x  x
writes       x  x  x        x  x  x        x  x  x        x  x  x     x  x       x
read            x        x  x  x  x     x  x  x  x     x  x  x  x
write           x           x  x  x        x  x  x        x  x  x
delete                                                       x  x
store                                                     x  x  x
accept                                                                x  x
display      *                                                        x  x       x
forms        x  x  x                                                  x  x       x
find      x  x  x  x     x  x  x  x     x  x  x  x      x  x  x  x    x  x
flush        x  x  x        x  x  x        x  x  x         x  x  x 

*O:P only

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DIBIOL/DBL - Statements