Some standard content:
1.1 Function
National Standard of the People's Republic of China
Programming language COBOL
Indexed I-0 module
GB/T 4092.6—92
Replaces GIB 4092. 6—83
The indexed I-0 module provides the function of accessing records in a mass storage file in a random or sequential manner. Each record in the indexed file is uniquely identified by the value of one or more keys in the record. 1.2 Level characteristics
Level 1 indexed IO provides partial functions for file control clauses, file description clauses, and clauses in the IO CONTROL section. In the procedure section, level 1 indexed IO provides partial functions for CLOSE, OPEN, READ, REWRITE, USE, and WRITE statements, and provides full functions for DELETE statements.
Level 2 index IO provides complete functionality for file control, file description clauses, and clauses in the IO CONTROL section. In the procedural section, level 2 index IO provides complete functionality for CLOSE, DELETE, OPEN, READ, REWRITE, START, USE, and WRITE statements.
1.3 Language concepts
1.3.1 Organization
Files organized by indexing are mass storage files that can access any record in the file by giving a specified record key value. Each key data item defined in a record of the file is associated with an index. Each such index represents a set of values for the corresponding key data item in each record. Therefore, each index is a mechanism that can provide access to any record in the file. Each index file has a primary index that represents the primary record key of each record in the file. Each record is added to the file, or is changed, or is deleted from the file entirely depending on the value of the primary record key. The primary record key must be unique for each record in a file and cannot be changed when a record is modified. The primary record key is specified in the RECORDKEY clause of the file control clause of the file. Secondary record keys provide secondary paths for retrieving records in the file. Such keys are named in the ALTERNATE RECORDKEY clause of the file control clause. The values of a particular secondary record key in each record may not be unique. When these values may not be unique, the DUPLICATES phrase must be used in the ALTER-NATE RECORDKEY clause to indicate this. 1.3-2 Access Modes
For indexed organizations, the order of sequential access is in ascending order of the reference key values according to the collation sequence of the file. During file processing, any key associated with a file may be used as a reference key. [In the case of a set of records with multiple key reference values, the reference order of the records is the order in which the records are written to the set. The START statement can be used to establish a starting point in an indexed file for a series of subsequent sequential retrievals.
When accessing files in random mode, input-output statements access records in the order specified by the programmer. For indexed organization, the programmer specifies the desired record by placing a value of the record key into the record key or sub-record key data item. For dynamic storage, the programmer can arbitrarily change from sequential access mode to random access mode using the appropriate format of the input-output statement.
1.3.3: File position indicator
The file position indicator is a conceptual entity used in this standard to simplify the exact instructions for accessing the next record from a given file during an input-output operation. The value of the file position indicator is affected only by CLOSE, OPEN, READ, and START statements. The concept of a file position indicator has no meaning for files opened in output or expansion mode. 1.3.4 I-0 Status
IO status is a two-character conceptual entity whose value indicates the status of an input/output operation during the execution of a CLOSE, DELETE, OPEN, READ, REWRITE, START, or WRITE statement and before the execution of any command statement associated with that input/output statement or before the execution of any applicable USE AFTER STANDARD EXCEPTION procedure. The IO status value is made available to COBOL programs by using the FILESTATUS clause in the file control clause of the corresponding file.
IO status is also used to determine whether an applicable USE AFTER STANDARD EXCEPTION procedure is to be executed. If conditions other than those covered under the heading "Successful Completion" occur, such a procedure may be executed according to the rules specified elsewhere. If the conditions present are those covered under the heading "Successful Completion", such procedures are not executed (see 4.8 USE Sentences).
Certain [-0 status values indicate critical error conditions. These are the error conditions beginning with the digits 3 or 4 and any error condition beginning with the digit 9 defined as critical by the implementer. If the I-0 status value for an input-output operation indicates such an error condition, it is up to the implementer to determine whether to execute any applicable USE AFTER STANDARD The action to be taken after the EXCEPTION procedure, or if no USEAFTERSTANDARDEXCEPTION procedure is available, the implementer determines what action to take after the standard processing of the input and output control system errors.
IO status indicates one of the following conditions based on the completion of the input and output operation: (1) Successful completion. The input and output statement is executed successfully. (2) Reach the end. The sequential READ statement is not executed successfully due to the hand end condition. (3) Invalid key. The input and output statement is not executed successfully due to the invalid key condition. (4) Permanent error. The input and output statement is not executed successfully due to an error, which makes the processing of the file unable to continue. The specified exception procedure is executed. Unless the implementer-defined technique is used to correct the permanent error condition, the permanent error condition will have an impact on all subsequent input and output operations of the file. (5) Logical error. The round-trip statement is caused by an incorrect sequence of input and output operations performed on the file, or a conflict with user-defined restrictions. Execution failed. (6) Implementer defined. The input/output statement failed to execute due to a condition specified by the implementer. The following table lists the values that are placed in the I-0 state when an input/output operation is performed on the prime document and the conditions named above occur. If more than one value is applicable, it is up to the implementer to determine which applicable value is placed in the IO state. (1) Successful completion
, 1I-0 state = 00. The input/output statement was executed successfully and no further information about the input/output operation is available. bI-0 state = 02. The input/output statement was executed successfully, but a duplicate key was detected. 13 For a READ statement, the key value of the current reference key is equal to the value of the same key in the next record in the current reference key. 2) For a REWRITE or WRITE statement, the record just written has at least one secondary record key that allows duplicates and establishes a duplicate chain value.
cI-0 state = 04. The READ statement was executed successfully, but the length of the record being processed is inconsistent with the fixed-length document attribute of the corresponding document.
GB/T 4092.6--92
dI-O status -05. The OPEN statement was successfully executed, but the referenced optional file did not exist when the OPEN statement was executed. If the merge mode was 1O or the expansion mode, the file has been created. (2) Unsuccessful termination of the end condition
I: IO status = 10. An attempt was made to execute a sequential READ statement, but the next logical record did not exist in the file due to the following reasons: 1) The end of the file has been reached,
2) This is the first attempt to execute a sequential READ statement for an optional input file that does not yet exist. (3) Unsuccessful termination of the invalid key condition
: T-() status = 21. A sequence error exists for a sequential access index file. Between the successful execution of the READ statement and the execution of the next REWRITE statement for that file, the program changed the value of the primary record key, or violated the requirement that the values of successive record keys are in reverse ascending order (see 4.9 WRITE statement). b.IO Status = 22. An attempt to write or rewrite a record of the index file will result in a single duplicate primary record chain or duplicate secondary record keys in the absence of the DUPLICATE phrase.
c. I-0 Status = 23. This condition occurs due to the following: 1) An attempt to access a record that does not exist in the file randomly. 2) An attempt to execute a START or random READ statement on an optional input file that does not exist. d. IO Status = 24. An attempt to write outside the boundaries determined external to the index file. The manner in which these boundaries are determined is implementor-specified. (4) Permanent error conditions that terminate unsuccessfully a. I0 Status = 30. A permanent error occurs and no further information is available related to input or output. b. IO Status = 35. A permanent error occurs due to an attempt to execute an OPEN statement with the INPUT, IO, or EXTEND phrase on a non-optional file that does not exist. CI-O Status = 37. A permanent error occurs due to an attempt to execute an OPEN statement on a file that does not support the open mode specified in the OPEN statement. Possible violations are: 1) The EXTEND or OUTPUT phrase was specified, but the file does not support write operations. 2) The 1-0 phrase was specified, but the file does not support input and output operations allowed for indexed files when opened in I-0 mode. 3) The INFUT phrase was specified, but the file does not support read operations. d, I-() state 38. A permanent error occurred due to an attempt to execute an OPEN statement on a file that had been previously closed with a lock.
... An attempt was made to execute a CL(>SE) statement on a file that was not in open mode. c. IO status = 43. In sequential access mode, the last input/output statement executed on the file before the DELETE or REWRITE statement was executed was not a successfully executed READ statement. d. I-0 status = 44. Boundary violation caused by the following factors: 1) An attempt was made to write or overwrite a record that was longer than the longest record allowed by the RECORDISVARYING clause of the associated file name or shorter than the shortest record.
2) In level 1, an attempt was made to write or overwrite a record that was different in length from the record being replaced on an indexed file. eI-O status = 46. An attempt was made to execute a sequential READ statement on a file that was opened in input or IO mode, and a valid next record was not established for the following reasons:
[1) The previous START statement was unsuccessful] GB/T 4092. 6--92
2) The previous READ statement was unsuccessful, but did not cause a terminal condition. 3) A previous READ statement caused an unterminated condition. IO state = 47. An attempt was made to execute a READ or START statement on a file that was not opened in input or IO mode. IO state = 48. An attempt was made to execute a WRITE statement on a file that was not opened in IO, output, or extended mode. b. IO state = 49. An attempt was made to execute a DELETE or REWRITE statement on a file that was not opened in IO mode. (6) Implementer-defined unsuccessful termination condition, 1-0 state 9x. An implementer-defined condition exists. This condition cannot be repeated with any condition of 1-0 state value 00 to 49. The value of x is defined by the implementer.
1.3.5 Invalid Key Condition
After a DELETEREAD, REWRITE, START, or WRITE statement is executed, an invalid key condition may occur. When an invalid key condition occurs, the execution of the input/output statement that identifies the condition is unsuccessful and the file is not affected (see 4.3 DELETE statement; 4.5 READ statement; 4.6 REWRITE statement; 4.7 START statement and 4.9 WRITE statement). After the input/output operation specified in an input/output statement is executed, if an invalid key condition occurs, the following sequence of actions occurs: (1) The I-0 state of the file connector associated with the statement is set to the value indicating the invalid key condition (see 1.3.4 I-0 state). (2) If the INVALIDKEY phrase is specified in the input/output statement, the USEAFTEREXCEPTION procedure associated with the file connector is not executed, and control is transferred to the command statement specified in the INVALIDKEY phrase. Execution then continues according to the rules for each statement specified in that command statement. If a procedure branch or conditional statement that explicitly causes a transfer of control is executed, control is transferred according to the corresponding rules for that statement. Otherwise, after the command statement line specified in the INVALIDKEY phrase is completed, control is transferred to the end of the input-output statement, and the NOT INVALIDKEY phrase (if specified) is ignored. (3) If the INVALIDKEY phrase is not specified in the input-output statement, the USEAFTEREXCEPTION procedure must be associated with the file connector and executed, and then control is transferred according to the rules of the USE statement. The NOTINVALIDKEY phrase (if specified) is ignored (see 4.8 USE statement). After the input-output operation specified by the input-output statement is executed, if the invalid key condition does not occur, the INVALIDKEY phrase is ignored (if specified). The I-() state of the file connector associated with the statement is modified, and the following actions are performed: (1) If an exception condition other than an invalid key condition occurs, control is transferred according to the rules of the USE statement after any USEAFTEREXCEPTION procedure associated with the file connector is executed (see 4.8 USE statement). (2) If no exception condition occurs, control is transferred to the end of the input/output statement, or if the NOTINVALIDKEY phrase is specified, to the command statement described by it. In the latter case, execution continues according to the rules for each statement described in that command statement. If a procedure branch or conditional statement that causes an explicit control transfer is executed, control is transferred according to the corresponding rules for that statement, otherwise, after the command statement described in the NOTINVALIDKEY phrase is executed, control is transferred to the end of the input/output statement. 1.3.6 Terminal Condition
After executing a READ statement, a terminal condition may occur (see 4.5 READ statement). 1.3.7. File attribute conflict conditions
Executing an OPEN, REWRITE, or WRITE statement may result in a file attribute conflict condition. When a file attribute conflict condition occurs, the execution of the input and output statements that recognize the condition is unsuccessful and the file is not affected (see 4.4 OPEN statement; 4.6 REWRITE statement and 4.9 WRITE statement). When a file attribute conflict condition is recognized, the following sequence of actions occurs: (1) A value indicating the file attribute conflict condition is placed in the 1. state associated with the file name (see 1.3.4-0 state). (2) The USEAFTEREXCEPTION procedure associated with the file name (if any) is executed. 2 Index I-0 Module Environment Section
2.1 Input and Output Sections
For information about input and output sections, see the description in 2.1 of the Sequence 1-0 module. 2.2 FILE-CONTROL Segment
GB/T4092.6—92
For information about the FILE-CONTROL segment, see the description in 2.2 of the sequential IO module. : 2.3 File Control Section
2.3.1 Function
The file control section describes the relevant physical attributes of the index file. 2.3.2 General format
SELFCT[OPTIONAL]File name1
ASSIGN TO
[Implementation name1
Word value1
RESERVE number1
LAREASJ
SEQUENTIAL
[ORGANIZATION IS] INDEXEI? ACCESS MODE IS RANDOMRECORI)KFYISData name1
DYNAMIC
［ALTERNATERECORDKEYISData name2［WITHDUPLICATESJ].[FILESTATUSISData name3]
2.3.3 Syntax Rules
(1) The SELECT clause must be specified first in the file control clause. The clauses following the SELECT clause can appear in any order.
(2) Each file described in the data section must be specified once and only once as a file name in the FILECONTROL section. Each file name specified in the SELECT clause must have a file description clause in the data section of the same program. (3) Word value 1 must be a non-numeric word value and cannot be a symbolic constant. The meaning and rules of what is allowed in word value 1 and what value it can have are defined by the implementor. 2.3.4 General rules
(1) If the file connector referenced by file name 1 is an external file connector (see 4.5 EXTERNAL clause in GB4092.12), then all file control clauses in the operational unit that reference this file connector must have the same specification for the OPTIONAL phrase
have a consistent specification for implementation name 1 or value 1 in the ASSIGN clause. The implementer specifies consistent rules for implementation name 1 or value 1.
have the same value for integer 1 in the RESERVE clause, and the same organization.
same access method.
data name 1 with the same relative position in the related record has the same data description clause. g-data name 2 has the same data description clause, and data name 2 has the same relative position, the same number of minor record keys, and the same DUPLICATES phrase in the related record.
(2) Data items on external media use the native character set. (3) For index files, it is assumed that the comparison sequence is associated with the source file set. This is the sequence of references to a given key value used for sequential processing of the file.
(4) The OPT1ONAL phrase applies only to files opened in input, IO, or extended mode. This phrase is required for files that are not necessarily accessed each time the target program runs. (5) The ASSIGN clause indicates the association between the file referenced by file name 1 and the storage medium referenced by implementation name 1 or value 1.
GB/T 4092.6—92
(6) The RESERVE clause of the index IO module is the same as the RESERVE clause of the sequential IO module. Therefore, the description of the RESERVE clause can be found in 2.9 RESERVE clause of the sequential IO module. (7) The FILE STATUS clause of the index IO module is the same as the FILESTATUS clause of the sequential IO module. Therefore, see 2.5 FILESTATUS Clause in the Sequential IO Module for a description of the FILESTATUS clause. The contents of the data items associated with the FILESTATUS clause for indexed files are described in 1.3.4I-0 Status, and (B) the ACCESSMODE clause, ALTERNATECORDKEY clause, ORGANIZATIONIS INDEXED clause, and RECORD KEY clause are described below. 2.4 ACCESS MODE Clause
2.4.1 Function
The ACCESS MODE clause indicates the order in which records are accessed in a file. 2.4.2 General Format
SEQUETIAL
RANDOM
ACCESSMODEIS
DYNAMIC
2.4.3 Syntax Rules
(1) The ACCESSMODEISRANDOM clause cannot be specified for a file name specified in the USING or GIVING phrase of a SORT or MERGE statement.
2.4.4 General Rules
(1) If the ACCESS MODE clause is not specified, sequential access is assumed. (2) If the access mode is sequential, the records in the file are accessed in the order determined by the file organization. For index files, this order is based on the ascending order of the record key values within a given reference key according to the file's collating sequence. (3) If the access mode is random, for index files, the value of the record key data item indicates the record to be accessed. (4) When the access mode is dynamic, the records in the file may be accessed sequentially and/or randomly. (5) If the associated file connector is an external file connector, then each file control clause in the run unit associated with that file connector must specify the same access mode. 2.5 ALTERNATERECORDKEY Clause
2.5.1 Function
The AI.TF ALTERNATERECORDKEY clause specifies a secondary record key that provides a secondary access path to records in the index file.
2.5.2 General Format
ALTERNATERECORDKEYIS dataname1[WITHDUPLICATES]2.5.3 Syntax Rules
(1) Dataname1 may be restricted.
(2) Dataname1 must be defined as a character data item in the record description associated with the file name to which the ALTERNATERECORDKEY clause pertains. (3) Dataname1 cannot reference a group item containing variable occurrences of data items. (4) Dataname1 cannot reference a data item whose leftmost character position corresponds to the leftmost character position of the primary record key or any other secondary record key associated with the file. (5) If the ALTERNATE RECORD KEY clause contains variable-length records, each minor record key must be contained within x character positions from the beginning of the record, where x is equal to the minimum record length specified for the file (see 3.8 RECORD clause in GB/T 4092.4). 2.5.4 General Rules
GB/T 4092.6--92
(1) The ALTERNATE RECORD KEY clause specifies the minor record key for the file to which this clause is associated. (2) The data description of dataname 1 and its relative position in the record must be the same as that used when the file was created. The number of minor record keys in the file must also be the same as that used when the file was created. (3) The DUPLICATES phrase specifies that the value of the associated minor record key may be repeated in any record in the file. If the DUPLICATES phrase is not specified, the value of the associated minor record key must not be repeated in any record in the file. (4) If the file has more than one record description clause, then data name 1 need only be described in one of those record description clauses. The same character position referenced by data name 1 in any record description clause is implicitly referenced as the corresponding key in all other record description clauses of that file.
(5) If the associated file connector is an external file connector, then in the run unit associated with that file connector, each file control clause must indicate the same data description clause for data name 1, the same relative position in the associated record, the same number of minor record keys, and the same DUPLICATES phrase. 2.6 ORGANIZATION IS INDEXED clause 2.6.1 Function
The ORGANIZATIONISINDEXED clause specifies that the index is organized as an index structure for the file. 2.6.2 General format
[ORGANIZATION IS J INDEXED
2.6.3 General rules
(1) The ORGANIZATION IS INDEXED clause specifies that the index organization is a logical structure of the file. The file organization is established when the file is created and cannot be changed thereafter.
(2) The index organization is a permanent logical file structure that identifies each record in the file by one or more key values in the record. 2.7 RECORD KEY clause
2.7.1 Function
The RECORD KEY clause specifies the primary record key, which provides the access path to the records in the index file. 2.7.2 General format
RECORDKEY IS data name 1
2.7.3 Syntax rules
(1) Data name 1 can be restricted. Www.bzxZ.net
(2) Data name 1 must reference a character data item in the record description associated with the file name to which the RECORDKEY clause belongs.
(3) Data name 1 cannot reference a group item containing variable-appearing data items. (4) If the index file contains variable-length records, the primary record key must be contained in the first x characters of the record, where x is equal to the minimum record length specified for the file (see clause 3-8 of RECORD in GB/T4092.1). 2.7.4 General Rules
(1) The RECORDKEY clause specifies the primary record key of the file to which the clause is associated. The value of the primary record key must be unique among the records of the file.
(2) The data description of dataname 1, as well as its relative position in the record, must be the same as that used when the file was created. (3) If a file has more than one record description clause, dataname 1 need only be described in one of those record description clauses. The same character position referenced by dataname 1 in any record description clause is implicitly referenced as the corresponding key in all other record description clauses of that file. (4) If the associated file connector is an external file connector, then in the run unit associated with that file connector, all file description clauses must specify the same data description clause for dataname 1 having the same relative position in the associated record. 2.8 I-OCONTROL Segment
2.8.1 Function
GB/T 4092.6—92
I-OCONTROL. The segment indicates the reset points and the storage areas shared by different files. In this version of Standard COBOL, the RERUN statement in the I-OCONTROL segment is considered obsolete because it will be deleted in later revisions of Standard COBOL.
2. 8-2 General format
IO-CONTROL.
RERUN ON
[File name]
Implementation name 1
[Integer 1 RECORDSOF File name 2]
Integer 2 CIOCK-UNITS
(Condition name 1
[SAME [RFCOR] AREA FOR File name 3 (File name 4} _.} 2.8.3 General rules
(1) The RERUN clause for indexed IO modules is a subset of the RERUN clause for sequential IO modules. Therefore, the description of the RERUN clause is given in 2.12 RERUN clause for sequential IO modules. (2) The SAME clause for indexed IO modules is the same as the SAME clause for sequential IO modules. Therefore, for the description of the SAME clause, see 2.13 SAME clause of the sequential JO module. 3 Data section of the index I-0 module
3.1 File section
For information about the file section, see 3.1 File section of the sequential I-0 module. 3.2 File description clause
3-2-1 Function
The file description clause provides information about the physical structure, identification and record name of an index file. 3.2.2 General format
FD file name1
[RECORDS
BL(CKCONTATIS[integer 1TO]integer 2ICHARACTERS
(CONTAINS number 3 CHARACTERS
RECORD
IS VARYING IN SIZE [LFROM integer 4TTO integer 5] CIIARACTERSIDEPENDINGONdata name1]CONTAINS integer 6TO integer 7CHARACTERSRECORD IS
IRECORDSARE!
VALUEOFimplementation name1IS
RECOR) IS
(STANDARD
OMITTED
data name2
(word value1
(data name3}
RECORDS AREJ
3.2.3 Syntax Rules
(1) The level indicator FD marks the beginning of the file description clause, which must be located before the file name 1. (2) The clauses following the file name can appear in any order. (3) The file description clause must be followed by one or more record description clauses. 3.2.4 General Rules
(1) The file description clause links the file name 1 to the file connector. GR/T 4092. 6—92
(2) The BLOCKCONTAINS clause of the index I-module is the same as the BLOCKCONTAINS clause of the sequential IO module. Therefore, the description of the BLOCKCONTAINS clause can be found in 3.3 BLOCKCONTAINS clause of the sequential IO module. (3) The DATA RECORDS clause of the index IO module is the same as the DATA RECORDS clause of the sequential IO module. Therefore, the description of the DATA RECORDS clause can be found in 3.3 BLOCKCONTAINS clause of the sequential IO module. (4) The LABELRECORDS clause of the index 1-0 module is identical to the LABELRECORLS clause of the sequential 1-0 module. Therefore, for a description of the LABEILRECORDS clause, see 3.6LABEILRECORDS clause of the sequential 1-0 module. (5) The RECORD clause of the index 1-0 module is identical to the RECORD clause of the sequential 1-0 module. Therefore, for a description of the RECORD clause, see 3.8RECORD clause of the sequential 1-0 module. (6) The VALUEOF clause of the index IO module is identical to the VAI.UEOF clause of the sequential IO module. Therefore, the description of the VALUEOF clause is in 3.9 VALUEOF clause of the sequential IO module. The VALUEOF clause is considered obsolete in this version of Standard COBOL because it will be deleted in future revisions of Standard COBOL. 4 Procedure section of the index 1-0 module
4.1 General description
When a USE statement for the index IO module exists in the COBO1 source program, the procedure section contains the procedures described in the section. The following is the general format of the procedure section when the USE statement exists.
PROCEDUREDIVISION.
DECLARATIVES.
(Section name SECTIUN.
USE statement
[segment name,
[sentence]]
ENDDECLARATIVES
ISection name SETION.
[segment name.
[] sub] -----
4.2 CLOSE statement
4.2.1 Function
The CLOSE statement terminates the processing of a file with an optional lock. 4.2.2 General format
CLOSE definition volume name 1 [WITHLOCK]
4.2.3 Syntax rules
(1) The files referenced in a CLOSE statement do not need to have the same organization or access mode. 4.2.4 General rules
(1) The CLOSE statement can only be executed on files in the indexing mode. (2) Indexed files belong to the non-sequential single or multi-volume or unit file type. The execution results of various CLOSE statements for such files are summarized in Table 1 below.
CI.CSSE statement format
CLOSE WITH LOCK
CB/T 4092.6—92
File Type; Non-Sequential Single or Multi-Volume or Unit A
The following are definitions of the symbols in the table. Here, the file is defined separately according to whether it is an input, output, or input-output file; otherwise, one definition may apply to input, output, and input-output. A, Close File
Input File and Input-Output File (Sequential Access Mode) If the file is located at its end and a label record is indicated for the file, the label is processed according to the implementer's standard label convention. When a label record is indicated but not present, or when a label record is not indicated but present, the behavior of the CLUSE statement is undefined, but the close operations specified by the implementer are performed. If the file is positioned at the end and no label record is indicated for the file, no label processing is performed, but other close operations specified by the implementer are performed. If the file is not positioned at its end, the close operations specified by the implementer are performed, but no end label processing is performed.
Input file and input output file (random or dynamic access mode); Output file (random, dynamic or sequential access mode): If a label record is indicated for the file, these labels are processed according to the standard labeling conventions of the implementation. When a label record is indicated but not present, or when a label record is not indicated but present, the behavior of the CLUSE statement is undefined, but the close operations specified by the implementer are performed. . If no label record is specified for the meaning of the volume, label processing is not performed, but other closing operations specified by the implementer are performed. B. File lock
The file is locked and cannot be opened again during this execution of this operation unit. (3) Executing the CLOSE statement will change the IO status value associated with file name 1 (see 1.3.4I-0 state), (4) If the optional input file does not exist, file processing is not performed on the file and the file position indicator is not changed. (5) After the CLOSE statement is successfully executed, the record area associated with file name 1 is no longer available. If the CLOSE statement fails to execute, the availability of the record area is undefined. (6) After the CLOSE statement is successfully executed, the file is removed from the open mode. And the file is no longer associated with the file connector.
(7) If in CLOSE If more than one file name is specified in the CLOSE statement, the result of executing this CLOSE statement is the same as a series of CLOSE statements written separately in the same order for each file name in the CLOSE statement. 4.3 DELETE Statement
4.3.1 Function
The DELETE statement logically removes a record from a mass storage file. 4.3.2 General Format
DELETE file name 1 RECORD
[INVALIDKEY command statement]
[NOT INVALID KEY command statement 2][END-DELETE ］
4.3.3 Syntax Rules
(1) For DELETE statements that reference sequential access files, the INVALIDKEY and NOTINVALIDKEY phrases must not be specified.
(2) For DELETE statements that reference non-sequential access files and do not specify that the USEAFTERSTANDARI)EXCEPTION procedure is applicable, the INVALIDKEY phrase must be specified. 4.3.4 General Rules
(1) When executing this statement, the file referenced by filename1 must be a mass storage file and must have been opened in 1-0 mode (4.4 OPEN statement).
(2) For sequential access files, the most recent input/output statement executed for filename1 before the DELETE statement is executed must be a successfully executed READ statement. The mass storage control system (MSCS) logically removes from the file the record accessed by the READ statement.
(3) For files in random or dynamic access mode, the MSCS logically removes from the file the record identified by the contents of the primary record key data item associated with file name 1. If the file does not contain the record pointed to by the key, an INVALIDKFY condition is generated (see 1.3.5 Invalid Chain Condition). (4) After the successful execution of the DELETE statement, the specified record has been logically deleted from the file and can no longer be accessed. (5) The execution of the DEL.ETE statement does not affect the contents of the record area or the contents of the data item referenced by the data name specified in the DEPENDINGON phrase in the RECORD clause associated with file name 1. (G) The file position indicator is not affected by the execution of the DELETE statement. (7) The execution of the DELETE statement causes the I-0 status value associated with file name 1 to be updated (see 1.3.4)-C) status) (8) After the successful or unsuccessful execution of the DELETE operation, the control transfer depends on whether the IN-VALIDKEY and NOTINVALIDKEY phrases are present in the DELETE statement (see 1.3.5 invalid key conditions). (9) The END-DELETE phrase limits the scope of the DELETE statement (see 6.5.4.3 scope of language in GB/T4092.1). 4.4 OPEN statement
4.4.1 Function
The OPEN statement initializes the processing of the file. 4.4.2 General format
INPUT(file name 1}.
OUTPUT(file name 2}
OPENO file name 3
EXTEND(file name 4)
4.4.3 Syntax rules
(1) The EXTEND phrase can only be used for files in sequential access mode. (2) All files referenced in the (PEN) phrase are not required to have the same organization or access mode. 4.4.4 General rules
(1) OPEN statement The successful execution of determines the availability of the file, puts the file in open mode, and associates the file with the file name through the file connector.
If the file physically exists and is recognized by the input and output control system, the file is available. Table 2 gives the results of opening available and unavailable files.
Input (optional file)
10 (optional file)
EXTEND
EXTEND (any file)
File available
GB/T 4092.6—92
Table 2 File availability
File unavailable
Normal open
Normal open
Normal open
Normal open
Normal open, file does not contain records
Normal open
Normal open
Open unsuccessful
Normal open; first read produces last condition or invalid key condition
Open and unsuccessful|| tt||Open causes file to be created
Open causes file to be created
Open fails
Open causes file to be created
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When the file is not open, statements that reference the file cannot be executed explicitly or implicitly. ING or GIVING phrases, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used according to the access method indicated on the left side of the row and can be used with the index file organization and the merge method given at the top of the column. Table 8 Allowable Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Import-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A fileFile lock
The file is locked and cannot be opened again during this execution of this run unit. (3) Executing the CLOSE statement will change the IO status value associated with file name 1 (see 1.3.4 I-0 status). (4) If the optional input file does not exist, no file processing is performed on the file and the file position indicator is not changed. (5) After the CLOSE statement is successfully executed, the record area associated with file name 1 is no longer available. If the CLOSE statement is not executed, the availability of the record area is undefined. (6) After the CLOSE statement is successfully executed, the file is removed from the open mode and is no longer associated with the file connector.
(7) If more than one file name 1 is specified in the CLOSE statement, the result of executing this CLOSE statement is the same as if a series of CLOSE statements were written separately in the same order for each file name 1 in the CLOSE statement. 4.3 DELETE Statement
4.3.1 Function
The DELETE statement logically removes a record from a mass storage file. 4.3.2 General Format
DELETE file name 1 RECORD
[INVALIDKEY command statement]
[NOT INVALID KEY command statement 2][END-DELETE]
4.3.3 Syntax Rules
(1) For a DELETE statement that references a sequential access mode file, the INVALIDKEY and NOTINVALIDKEY phrases cannot be specified.
(2) For IEI.FTE statements that reference a file in nonsequential access mode and do not indicate that the USEAFTERSTANDARI)EXCEPTION procedure is applicable, the INVALID)KEY phrase must be specified. 4.3.4 General Rules
(1) When executing this statement, the file referenced by filename1 must be a mass storage file and must have been opened in mode 1-0 (4.4 OPEN statement).
(2) For files in sequential access mode, the most recent input/output statement executed for filename1 before the DELETE statement is executed must be a successfully executed READ statement. The mass storage control system (MSCS) logically removes the records accessed by the READ statement from the file.
(3) For files in random or dynamic access mode, MSCS logically removes from the file the record identified by the contents of the primary record key data item associated with file name 1. If the file does not contain the record pointed to by the key, an INVALIDKFY condition is generated (see 1.3.5 Invalid Chain Condition). (4) After the successful execution of the DELETE statement, the specified record has been logically deleted from the file and can no longer be accessed. (5) The execution of the DEL.ETE statement does not affect the contents of the record area or the contents of the data item referenced by the data name specified in the DEPENDINGON phrase in the RECORD clause associated with file name 1. (G) The file position indicator is not affected by the execution of the DELETE statement. (7) The execution of the DELETE statement causes the I-0 status value associated with file name 1 to be updated (see 1.3.4)-C) status) (8) After the successful or unsuccessful execution of the DELETE operation, the control transfer depends on whether the IN-VALIDKEY and NOTINVALIDKEY phrases are present in the DELETE statement (see 1.3.5 invalid key conditions). (9) The END-DELETE phrase limits the scope of the DELETE statement (see 6.5.4.3 scope of language in GB/T4092.1). 4.4 OPEN statement
4.4.1 Function
The OPEN statement initializes the processing of the file. 4.4.2 General format
INPUT(file name 1}.
OUTPUT(file name 2}
OPENO file name 3
EXTEND(file name 4)
4.4.3 Syntax rules
(1) The EXTEND phrase can only be used for files in sequential access mode. (2) All files referenced in the (PEN) phrase are not required to have the same organization or access mode. 4.4.4 General rules
(1) OPEN statement The successful execution of determines the availability of the file, puts the file in open mode, and associates the file with the file name through the file connector.
If the file physically exists and is recognized by the input and output control system, the file is available. Table 2 gives the results of opening available and unavailable files.
Input (optional file)
10 (optional file)
EXTEND
EXTEND (any file)
File available
GB/T 4092.6—92
Table 2 File availability
File unavailable
Normal open
Normal open
Normal open
Normal open
Normal open, file does not contain records
Normal open
Normal open
Open unsuccessful
Normal open; first read produces last condition or invalid key condition
Open and unsuccessful|| tt||Open causes file to be created
Open causes file to be created
Open fails
Open causes file to be created
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When the file is not open, statements that reference the file cannot be executed explicitly or implicitly. ING or GIVING phrases, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used according to the access mode indicated on the left side of the row and can be used with the index file organization and the merge mode given at the top of the column. Table 8 Allowable Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Import-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A fileFile lock
The file is locked and cannot be opened again during this execution of this run unit. (3) Executing the CLOSE statement will change the IO status value associated with file name 1 (see 1.3.4 I-0 status). (4) If the optional input file does not exist, no file processing is performed on the file and the file position indicator is not changed. (5) After the CLOSE statement is successfully executed, the record area associated with file name 1 is no longer available. If the CLOSE statement is not executed, the availability of the record area is undefined. (6) After the CLOSE statement is successfully executed, the file is removed from the open mode and is no longer associated with the file connector.
(7) If more than one file name 1 is specified in the CLOSE statement, the result of executing this CLOSE statement is the same as if a series of CLOSE statements were written separately in the same order for each file name 1 in the CLOSE statement. 4.3 DELETE Statement
4.3.1 Function
The DELETE statement logically removes a record from a mass storage file. 4.3.2 General Format
DELETE file name 1 RECORD
[INVALIDKEY command statement]
[NOT INVALID KEY command statement 2][END-DELETE]
4.3.3 Syntax Rules
(1) For a DELETE statement that references a sequential access mode file, the INVALIDKEY and NOTINVALIDKEY phrases cannot be specified.
(2) For IEI.FTE statements that reference a file in nonsequential access mode and do not indicate that the USEAFTERSTANDARI)EXCEPTION procedure is applicable, the INVALID)KEY phrase must be specified. 4.3.4 General Rules
(1) When executing this statement, the file referenced by filename1 must be a mass storage file and must have been opened in mode 1-0 (4.4 OPEN statement).
(2) For files in sequential access mode, the most recent input/output statement executed for filename1 before the DELETE statement is executed must be a successfully executed READ statement. The mass storage control system (MSCS) logically removes the records accessed by the READ statement from the file.
(3) For files in random or dynamic access mode, MSCS logically removes from the file the record identified by the contents of the primary record key data item associated with file name 1. If the file does not contain the record pointed to by the key, an INVALIDKFY condition is generated (see 1.3.5 Invalid Chain Condition). (4) After the successful execution of the DELETE statement, the specified record has been logically deleted from the file and can no longer be accessed. (5) The execution of the DEL.ETE statement does not affect the contents of the record area or the contents of the data item referenced by the data name specified in the DEPENDINGON phrase in the RECORD clause associated with file name 1. (G) The file position indicator is not affected by the execution of the DELETE statement. (7) The execution of the DELETE statement causes the I-0 status value associated with file name 1 to be updated (see 1.3.4)-C) status) (8) After the successful or unsuccessful execution of the DELETE operation, the control transfer depends on whether the IN-VALIDKEY and NOTINVALIDKEY phrases are present in the DELETE statement (see 1.3.5 invalid key conditions). (9) The END-DELETE phrase limits the scope of the DELETE statement (see 6.5.4.3 scope of language in GB/T4092.1). 4.4 OPEN statement
4.4.1 Function
The OPEN statement initializes the processing of the file. 4.4.2 General format
INPUT(file name 1}.
OUTPUT(file name 2}
OPENO file name 3
EXTEND(file name 4)
4.4.3 Syntax rules
(1) The EXTEND phrase can only be used for files in sequential access mode. (2) All files referenced in the (PEN) phrase are not required to have the same organization or access mode. 4.4.4 General rules
(1) OPEN statement The successful execution of determines the availability of the file, puts the file in open mode, and associates the file with the file name through the file connector.
If the file physically exists and is recognized by the input and output control system, the file is available. Table 2 gives the results of opening available and unavailable files.
Input (optional file)
10 (optional file)
EXTEND
EXTEND (any file)
File available
GB/T 4092.6—92
Table 2 File availability
File unavailable
Normal open
Normal open
Normal open
Normal open
Normal open, file does not contain records
Normal open
Normal open
Open unsuccessful
Normal open; first read produces last condition or invalid key condition
Open and unsuccessful|| tt||Open causes file to be created
Open causes file to be created
Open fails
Open causes file to be created
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When the file is not open, statements that reference the file cannot be executed explicitly or implicitly. ING or GIVING phrases, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used according to the access mode indicated on the left side of the row and can be used with the index file organization and the merge mode given at the top of the column. Table 8 Allowable Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Import-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A file6—92
If an IEI.FTE statement is executed for a file in which file name 1 is stored, the INVALIDKEY phrase must be specified. 4.3.4 General Rules
(1) At the time this statement is executed, the file referenced by file name 1 must be a mass storage file and must have been opened in mode 1-0 (4.4 OPEN statement).
(2) For files in sequential access mode, the most recent input/output statement executed for file name 1 before the DELETE statement is executed must have been a successfully executed READ statement. The mass storage control system (MSCS) logically removes from the file the record accessed by the READ statement.
(3) For files in random or dynamic access mode, the MSCS logically removes from the file the record identified by the contents of the primary record key data item associated with file name 1. If the file does not contain the record identified by the key, an INVALIDKEY condition is generated (see 1.3.5 Invalid Chain Condition). (4) After the successful execution of the DELETE statement, the specified record has been logically deleted from the file and can no longer be accessed. (5) The execution of the DELETE statement does not affect the contents of the record area or the contents of the data items referenced by the data names specified in the DEPENDINGON phrase in the RECORD clause associated with file name 1. (G) The file position indicator is not affected by the execution of the DELETE statement. (7) The execution of the DELETE statement causes the I-0 status value associated with file name 1 to be updated (see 1.3.4)-C) status) (8) After the successful or unsuccessful execution of the DELETE operation, the control transfer depends on whether the IN-VALIDKEY and NOTINVALIDKEY phrases are present in the DELETE statement (see 1.3.5 invalid key conditions). (9) The END-DELETE phrase limits the scope of the DELETE statement (see 6.5.4.3 language scope in GB/T 4092.1). 4.4OPEN statement
4.4.1 Function
OPEN statement initializes the processing of files. 4.4.2 General format
INPUT(file name 1}.
OUTPUT(file name 2}
OPENO file name 3
EXTEND(file name 4)
4.4.3 Syntax rules
(1) The EXTEND phrase can only be used for files in sequential access mode. (2) All files referenced in the (PEN statement are not required to have the same organization or access mode. 4.4.4 General rules
(1) OPEN statement The successful execution of determines the availability of the file, puts the file in open mode, and associates the file with the file name through the file connector.
If the file physically exists and is recognized by the input and output control system, the file is available. Table 2 gives the results of opening available and unavailable files.
Input (optional file)
10 (optional file)
EXTEND
EXTEND (any file)
File available
GB/T 4092.6—92
Table 2 File availability
File unavailable
Normal open
Normal open
Normal open
Normal open
Normal open, file does not contain records
Normal open
Normal open
Open unsuccessful
Normal open; first read produces last condition or invalid key condition
Open and unsuccessful|| tt||Open causes file to be created
Open causes file to be created
Open fails
Open causes file to be created
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When the file is not open, statements that reference the file cannot be executed explicitly or implicitly. ING or GIVING phrases, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used according to the access mode indicated on the left side of the row and can be used with the index file organization and the merge mode given at the top of the column. Table 8 Allowable Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Import-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A file6—92
If an IEI.FTE statement is executed for a file in which file name 1 is stored, the INVALIDKEY phrase must be specified. 4.3.4 General Rules
(1) At the time this statement is executed, the file referenced by file name 1 must be a mass storage file and must have been opened in mode 1-0 (4.4 OPEN statement).
(2) For files in sequential access mode, the most recent input/output statement executed for file name 1 before the DELETE statement is executed must have been a successfully executed READ statement. The mass storage control system (MSCS) logically removes from the file the record accessed by the READ statement.
(3) For files in random or dynamic access mode, the MSCS logically removes from the file the record identified by the contents of the primary record key data item associated with file name 1. If the file does not contain the record identified by the key, an INVALIDKEY condition is generated (see 1.3.5 Invalid Chain Condition). (4) After the successful execution of the DELETE statement, the specified record has been logically deleted from the file and can no longer be accessed. (5) The execution of the DELETE statement does not affect the contents of the record area or the contents of the data items referenced by the data names specified in the DEPENDINGON phrase in the RECORD clause associated with file name 1. (G) The file position indicator is not affected by the execution of the DELETE statement. (7) The execution of the DELETE statement causes the I-0 status value associated with file name 1 to be updated (see 1.3.4)-C) status) (8) After the successful or unsuccessful execution of the DELETE operation, the control transfer depends on whether the IN-VALIDKEY and NOTINVALIDKEY phrases are present in the DELETE statement (see 1.3.5 invalid key conditions). (9) The END-DELETE phrase limits the scope of the DELETE statement (see 6.5.4.3 language scope in GB/T 4092.1). 4.4OPEN statement
4.4.1 Function
OPEN statement initializes the processing of files. 4.4.2 General format
INPUT(file name 1}.
OUTPUT(file name 2}
OPENO file name 3
EXTEND(file name 4)
4.4.3 Syntax rules
(1) The EXTEND phrase can only be used for files in sequential access mode. (2) All files referenced in the (PEN statement are not required to have the same organization or access mode. 4.4.4 General rules
(1) OPEN statement The successful execution of determines the availability of the file, puts the file in open mode, and associates the file with the file name through the file connector.
If the file physically exists and is recognized by the input and output control system, the file is available. Table 2 gives the results of opening available and unavailable files.
Input (optional file)
10 (optional file)
EXTEND
EXTEND (any file)
File available
GB/T 4092.6—92
Table 2 File availability
File unavailable
Normal open
Normal open
Normal open
Normal open
Normal open, file does not contain records
Normal open
Normal open
Open unsuccessful
Normal open; first read produces last condition or invalid key condition
Open and unsuccessful|| tt||Open causes file to be created
Open causes file to be created
Open fails
Open causes file to be created
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When the file is not open, statements that reference the file cannot be executed explicitly or implicitly. ING or GIVING phrases, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used according to the access mode indicated on the left side of the row and can be used with the index file organization and the merge mode given at the top of the column. Table 8 Allowable Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Import-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A file6—92
Table 2 Availability of File
File Unavailable
Normal Open
Normal Open
Normal Open
Normal Open
Normal Open, File Contains No Record
Normal Open
Normal Open
Open Failed
Normal Open; First Read Produces End Condition or Invalid Key Condition
Open Failed
Open Makes File Result
Open Makes File Result
Open Failed
Open Makes File Result
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When a file is not open, statements that refer to the file cannot be executed explicitly or implicitly, except for a MERGE statement with a USING or GIVING phrase, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used in the access mode indicated on the left side of the row and can be used with the index file organization and the merge mode given at the top of the column. Table 8 Permitted Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Input-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A file6—92
Table 2 Availability of File
File Unavailable
Normal Open
Normal Open
Normal Open
Normal Open
Normal Open, File Contains No Record
Normal Open
Normal Open
Open Failed
Normal Open; First Read Produces End Condition or Invalid Key Condition
Open Failed
Open Makes File Result
Open Makes File Result
Open Failed
Open Makes File Result
(2) Successful execution of the OPEN statement makes the associated record area available to the program. If the file connector associated with the file name is an external file connector, the run unit has only one record area associated with this file connector. (3) When a file is not open, statements that refer to the file cannot be executed explicitly or implicitly, except for a MERGE statement with a USING or GIVING phrase, an OFEN statement, or a SORT statement with a USING or GIVING phrase. (4) An OPEN statement must be successfully executed before any allowed input or output statement can be executed. In Table 3, the × at the intersection indicates an allowed statement. These statements are used in the access mode indicated on the left side of the row and can be used with the index file organization and the merge mode given at the top of the column. Table 8 Permitted Statements
File Access Method
REWRITE
DELETE
REWRITE
DELETE
REWRITE
DELETE
Open Method
Input-Output
(5) Multiple files can be opened in the same run unit using the INPUT, OUTPUT, EXTEND, and IO phrases. A file
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