OpenCOBOL の場合、標準入力/標準出力フィルター プログラムのサンプルを次に示します。
>>SOURCE FORMAT IS FIXED
*> ***************************************************************
*><* ===========
*><* filter
*><* ===========
*><* :Author: Brian Tiffin
*><* :Date: 20090207
*><* :Purpose: Standard IO filters
*><* :Tectonics: cobc -x filter.cob
*> ***************************************************************
identification division.
program-id. filter.
environment division.
configuration section.
input-output section.
file-control.
select standard-input assign to keyboard.
select standard-output assign to display.
data division.
file section.
fd standard-input.
01 stdin-record pic x(32768).
fd standard-output.
01 stdout-record pic x(32768).
working-storage section.
01 file-status pic x value space.
88 end-of-file value high-value
when set to false is low-value.
*> ***************************************************************
procedure division.
main section.
00-main.
perform 01-open
perform 01-read
perform
until end-of-file
perform 01-transform
perform 01-write
perform 01-read
end-perform
.
00-leave.
perform 01-close
.
goback.
*> end main
support section.
01-open.
open input standard-input
open output standard-output
.
01-read.
read standard-input
at end set end-of-file to true
end-read
.
*> All changes here
01-transform.
move stdin-record to stdout-record
.
*>
01-write.
write stdout-record end-write
.
01-close.
close standard-input
close standard-output
.
end program filter.
*><*
*><* Last Update: dd-Mmm-yyyy
これは、たまたまテキスト ファイルを読み込んだ LINAGE の使用例です。
*****************************************************************
* Example of LINAGE File Descriptor
* Author: Brian Tiffin
* Date: 10-July-2008
* Tectonics: $ cocb -x linage-demo.cob
* $ ./linage-demo <filename ["linage-demo.cob"]>
* $ cat -n mini-report
*****************************************************************
IDENTIFICATION DIVISION.
PROGRAM-ID. linage-demo.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
select optional data-file assign to file-name
organization is line sequential
file status is data-file-status.
select mini-report assign to "mini-report".
DATA DIVISION.
FILE SECTION.
FD data-file.
01 data-record.
88 endofdata value high-values.
02 data-line pic x(80).
FD mini-report
linage is 16 lines
with footing at 15
lines at top 2
lines at bottom 2.
01 report-line pic x(80).
WORKING-STORAGE SECTION.
01 command-arguments pic x(1024).
01 file-name pic x(160).
01 data-file-status pic 99.
01 lc pic 99.
01 report-line-blank.
02 filler pic x(18) value all "*".
02 filler pic x(05) value spaces.
02 filler pic x(34)
VALUE "THIS PAGE INTENTIONALLY LEFT BLANK".
02 filler pic x(05) value spaces.
02 filler pic x(18) value all "*".
01 report-line-data.
02 body-tag pic 9(6).
02 line-3 pic x(74).
01 report-line-header.
02 filler pic x(6) VALUE "PAGE: ".
02 page-no pic 9999.
02 filler pic x(24).
02 filler pic x(5) VALUE " LC: ".
02 header-tag pic 9(6).
02 filler pic x(23).
02 filler pic x(6) VALUE "DATE: ".
02 page-date pic x(6).
01 page-count pic 9999.
PROCEDURE DIVISION.
accept command-arguments from command-line end-accept.
string
command-arguments delimited by space
into file-name
end-string.
if file-name equal spaces
move "linage-demo.cob" to file-name
end-if.
open input data-file.
read data-file
at end
display
"File: " function trim(file-name) " open error"
end-display
go to early-exit
end-read.
open output mini-report.
write report-line
from report-line-blank
end-write.
move 1 to page-count.
accept page-date from date end-accept.
move page-count to page-no.
write report-line
from report-line-header
after advancing page
end-write.
perform readwrite-loop until endofdata.
display
"Normal termination, file name: "
function trim(file-name)
" ending status: "
data-file-status
end-display.
close mini-report.
* Goto considered harmful? Bah! :)
early-exit.
close data-file.
exit program.
stop run.
****************************************************************
readwrite-loop.
move data-record to report-line-data
move linage-counter to body-tag
write report-line from report-line-data
end-of-page
add 1 to page-count end-add
move page-count to page-no
move linage-counter to header-tag
write report-line from report-line-header
after advancing page
end-write
end-write
read data-file
at end set endofdata to true
end-read
.
*****************************************************************
* Commentary
* LINAGE is set at a 20 line logical page
* 16 body lines
* 2 top lines
* A footer line at 15 (inside the body count)
* 2 bottom lines
* Build with:
* $ cobc -x -Wall -Wtruncate linage-demo.cob
* Evaluate with:
* $ ./linage-demo
* This will read in linage-demo.cob and produce mini-report
* $ cat -n mini-report
*****************************************************************
END PROGRAM linage-demo.
これらのサンプルと Gilbert の回答があれば、問題に取り組むのに十分なはずですが、これらの例は適切なエラー処理が苦手であることに注意してください。標準入出力の例、またはコマンド ライン引数 (または引数がない) に応じたファイル名別の例については、OpenCOBOL FAQ の ocdoc.cob プログラムを参照してください。
オフトピック: ocdoc.cob 自体に対する ocdoc パスの出力は、http://opencobol.add1tocobol.com/ocdoc.html で見ることができます( なぜそれについて言及するのですか? Pygments の COBOL レキシコン ハイライターがメインに受け入れられたばかりです。バージョン 1.6 以降では、COBOL (コンテキストフリー) 字句強調表示が可能になります。)