一步步Cobol 400 上手自学入门教程01 - 基础概念

先学习基础概念

1、COBOL字符：包含：

1. 　User-defined words 用户定义字符
2. ŸSystem-names
3. ŸReserved words 关键字

2、用户定义字符User-defined words：合法的定义：

1. Ÿ A - Z
2. Ÿ a - z
3. Ÿ 0 - 9
4. Ÿ - (连字符).

3、系统名 System-names

1. Computer-names
2. ŸLanguage-names
3. ŸImplementor-names:
   1. Environment-name
   2. Assignment-name

4、关键词 Reserved words

ACCEPT
ACCESS
ACQUIRE
ADD
ADDRESS
ADVANCING
AFTER
ALL
ALPHABET
ALPHABETIC
ALPHABETIC-LOWER
ALPHABETIC-UPPER
ALPHANUMERIC
ALPHANUMERIC-EDITED
ALSO
ALTER
ALTERNATE
AND
ANY
ARE
AREA
AREAS
ARITHMETIC
ASCENDING
ASSIGN
AT
AUTHOR
AUTO
AUTO-SKIP
BACKGROUND-COLOR
BACKGROUND-COLOUR
B-AND
BEEP
BEFORE
BELL
B-EXOR
BINARY
BIT
BITS
BLANK
B-LESS
BLINK
BLOCK
B-NOT
BOOLEAN
B-OR
BOTTOM
BY
CALL
CANCEL
CD
CF
CH
CHARACTER
CHARACTERS
CLASS
CLOCK-UNITS
CLOSE
COBOL
CODE
CODE-SET
COL
COLLATING
COLUMN
COMMA
COMMIT
COMMITMENT
COMMON
COMMUNICATION
COMP
COMP-
COMP-
COMPUTATIONAL
COMPUTATIONAL-
COMPUTATIONAL-
COMPUTE
CONFIGURATION
CONNECT
CONTAINED
CONTAINS
CONTENT
CONTINUE
CONTROL
CONTROL-AREA
CONTROLS
CONVERSION
CONVERTING
COPY
CORR
CORRESPONDING
COUNT
CRT
CRT-UNDER
CURRENCY
CURRENT
CURSOR
DATA
DATE
DATE-COMPILED
DATE-WRITTEN
DAY
DAY-OF-WEEK
DB
DB-ACCESS-CONTROL-KEY
DB-DATA-NAME
DB-EXCEPTION
DB-FORMAT-NAME
DB-RECORD-NAME
DB-SET-NAME
DB-STATUS
DBCS
DE
DEBUG-CONTENTS
DEBUG-ITEM
DEBUG-LINE
DEBUG-NAME
DEBUG-SUB-
DEBUG-SUB-
DEBUG-SUB-
DEBUGGING
DECIMAL-POINT
DECLARATIVES
DEFAULT
DELETE
DELIMITED
DELIMITER
DEPENDING
DESCENDING
DESTINATION
DETAIL
DISABLE
DISCONNECT
DISPLAY
DISPLAY-
DISPLAY-n
DIVIDE
DIVISION
DOWN
DROP
DUPLICATE
DUPLICATES
DYNAMIC
EGI
EJECT
ELSE
EMI
EMPTY-CHECK
ENABLE
END
END-ACCEPT
END-ADD
END-CALL
END-COMPUTE
END-DELETE
END-DIVIDE
END-EVALUATE
END-IF
END-MULTIPLY
END-OF-PAGE
END-PERFORM
END-READ
END-RECEIVE
END-RETURN
END-REWRITE
END-SEARCH
END-START
END-STRING
END-SUBTRACT
END-UNSTRING
END-WRITE
ENTER
ENVIRONMENT
EOP
EQUAL
EQUALS
ERASE
ERROR
ESI
EVALUATE
EVERY
EXCEEDS
EXCEPTION
EXCLUSIVE
EXIT
EXOR
EXTEND
EXTERNAL
EXTERNALLY-DESCRIBED-KEY
FALSE
FD
FETCH
FILE
FILE-CONTROL
FILES
FILLER
FINAL
FIND
FINISH
FIRST
FOOTING
FOR
FOREGROUND-COLOR
FOREGROUND-COLOUR
FORMAT
FREE
FROM
FULL
FUNCTION
GENERATE
GET
GIVING
GLOBAL
GO
GOBACK
GREATER
GROUP
HEADING
HIGHLIGHT
HIGH-VALUE

HIGH-VALUES
I-O
I-O-CONTROL
ID
IDENTIFICATION
IF
IN
INDEX
INDEXED
INDEX-N
INDIC
INDICATE
INDICATOR
INDICATORS
INITIAL
INITIALIZE
INITIATE
INPUT
INPUT-OUTPUT
INSPECT
INSTALLATION
INTO
INVALID
IS
JUST
JUSTIFIED
KEEP
KEY
LABEL
LAST
LD
LEADING
LEFT
LEFT-JUSTIFY
LENGTH
LENGTH-CHECK
LESS
LIKE
LIMIT
LIMITS
LINAGE
LINAGE-COUNTER
LINE
LINE-COUNTER
LINES
LINKAGE
LOCALLY
LOCK
LOW-VALUE
LOW-VALUES
MEMBER
MEMORY
MERGE
MESSAGE
MODE
MODIFIED
MODIFY
MODULES
MOVE
MULTIPLE
MULTIPLY
NATIVE
NEGATIVE
NEXT
NO
NO-ECHO
NONE
NOT
NULL
NULLS
NUMBER
NUMERIC
NUMERIC-EDITED
OBJECT-COMPUTER
OCCURS
OF
OFF
OMITTED
ON
ONLY
OPEN
OPTIONAL
OR
ORDER
ORGANIZATION
OTHER
OUTPUT
OVERFLOW
OWNER
PACKED-DECIMAL
PADDING
PAGE
PAGE-COUNTER
PERFORM
PF
PH
PIC
PICTURE
PLUS
POINTER
POSITION
POSITIVE
PRESENT
PRINTING
PRIOR
PROCEDURE
PROCEDURES
PROCEED
PROCESS
PROGRAM
PROGRAM-ID
PROMPT
PROTECTED
PURGE
QUEUE
QUOTE
QUOTES
RANDOM
RD
READ
READY
REALM
RECEIVE
RECONNECT
RECORD
RECORD-NAME
RECORDS
REDEFINES
REEL
REFERENCE
REFERENCE-MONITOR
REFERENCES
RELATION
RELATIVE
RELEASE
REMAINDER
REMOVAL
RENAMES
REPEATED
REPLACE
REPLACING
REPORT
REPORTING
REPORTS
REQUIRED
RERUN
RESERVE
RESET
RETAINING
RETRIEVAL
RETURN
RETURN-CODE
REVERSED
REVERSE-VIDEO
REWIND
REWRITE
RD
RF
RH
RIGHT
RIGHT-JUSTIFY
ROLLBACK
ROLLING
ROUNDED
RUN
SAME
SCREEN
SD
SEARCH
SECTION
SECURE
SECURITY
SEGMENT
SEGMENT-LIMIT
SELECT
SEND
SENTENCE
SEPARATE
SEQUENCE
SEQUENTIAL
SET
SHARED
SIGN
SIZE
SKIP1
SKIP2
SKIP3
SORT
SORT-MERGE
SORT-RETURN
SOURCE
SOURCE-COMPUTER
SPACE
SPACE-FILL
SPACES
SPECIAL-NAMES
STANDARD
STANDARD-
STANDARD-
START
STARTING
STATUS
STOP
STORE
STRING
SUB-QUEUE-
SUB-QUEUE-
SUB-QUEUE-
SUB-SCHEMA
SUBFILE
SUBTRACT
SUM
SUPPRESS
SYMBOLIC
SYNC
SYNCHRONIZED
TABLE
TALLYING
TAPE
TENANT
TERMINAL
TERMINATE
TEST
TEXT
THAN
THEN
THROUGH
THRU
TIME
TIMES
TITLE
TO
TOP
TRAILING
TRAILING-SIGN
TRANSACTION
TRUE
TYPE
UNDERLINE
UNEQUAL
UNIT
UNSTRING
UNTIL
UP
UPDATE
UPON
USAGE
USAGE-MODE
USE
USING
VALID
VALIDATE
VALUE
VALUES
VARYING
WAIT
WHEN
WHEN-COMPILED
WITH
WITHIN
WORDS
WORKING-STORAGE
WRITE
ZERO
ZEROES
ZERO-FILL
ZEROS
<
< =
+
*
**
-
/
>
> =
=

近500个关键字.

5、节和段 Sections and Paragraphs

层次：

Ÿ Identification Division
　　Paragraphs
　　　　Entries
　　　　　　Clauses
Ÿ Environment Division
　　Sections
　　　　Paragraphs
　　　　　　Entries
　　　　　　　　Clauses
　　　　　　　　　　Phrases
Ÿ Data Division
　　Sections
　　　　Entries
　　　　　　Clauses
　　　　　　　　Phrases
Ÿ Procedure Division
　　Sections
　　　　Paragraphs
　　　　　　Sentences
　　　　　　　　Statements
　　　　　　　　　　Phrases

备注：

4个部：

• 　　1、标识部（IDENTIFICATIONDIVISION）：用于标识程序名。
• 　　2、环境部（ENVIRONMENTDIVISION）：用于说明程序运行的环境。
• 　　3、数据部（DATADIVISION）：用于说明程序中涉及的所有数据。
• 　　4、过程部（PROCEDUREDIVISION）：是程序的核心部分，它决定计算机应进行什么操作。

部（Division)一部可包括若干节
节（Section)一节可包含若干段
段（Paragraph)一段可包含若干句子
句子（Sentence)一个句子可包含若干语句
语句(Statement)制定计算机完成一定的操作
子句(Clause)制定完成某一方面的功能

6、Cobol 代码格式

　　第1至6列为”标号区”

　　　　序列号是可选的。如果使用的话，序列号必须在列1到6

　　第7列为”续行标志区”
　　第8至此11列，称为”A区”。程序中有些内容如部头，节头，段头，层号01，层号77及文件描述符FD等应从A区开始写。
　　第12至此72列，称为”B区”。写程序中的正文部分。如过程部中的句子只能从B区开始写。
　　第73至80列，称为”注释区”。

格式演示：