1. COBOLãšã¯ïŒãã®ç¹åŸŽãšå©ç¹
COBOLïŒCommon Business-Oriented LanguageïŒã¯ãæ±çšããžãã¹åãèšèªãšãããããäž»ã«ããžãã¹åŠçã§äœ¿çšãããäŒçµ±çãªããã°ã©ãã³ã°èšèªã§ãããã®ç¹åŸŽãå©ç¹ãå ·äœçã«è§£èª¬ããåã«ããã®åºæ¬çãªæŠèŠãšæŽå²ã«ã€ããŠè§ŠããŠãããŸãããã
1.1 COBOLã®æŠèŠãšæŽå²
COBOLã¯ã1950幎代åŸåã«éçºãããã¢ã¡ãªã«ã®ããã°ã©ãã³ã°èšèªã§ããéèãä¿éºãæ¿åºãªã©ã®å€§äŒæ¥ã®ããžãã¹åŠçãè¡ãããã®èšèªãšããŠèšèšãããŸããã
COBOLã¯ãåå¿è ãåŠã³ãããèšèªãšããŠç¥ãããŠããŸãããã®çç±ã¯ãCOBOLãè±èªã®ãããªèªç¶èšèªã«åºã¥ããŠããããã§ãããã®ããããã¥ãŒãã³ãã¬ã³ããªãŒãªã³ãŒããæžããã®ã倧ããªç¹åŸŽãšãããã§ãããã
ãŸããCOBOLã¯ä¿¡é Œæ§ãéåžžã«é«ããšãããŠããŸããããã¯ãéèŠãªããžãã¹ã·ã¹ãã ãé·æéå®å®ããŠéçšããããã®åºç€ãšããŠå©çšãããŠããçµæã§ãã
1.2 COBOLã®ç¹åŸŽ
COBOLã®æ倧ã®ç¹åŸŽã¯ããã®èªã¿ããããšã¡ã³ããã³ã¹æ§ã§ããCOBOLã¯ããã®èªç¶èšèªã«è¿ãæžãæ¹ãããã³ãŒãã®èªè§£ãã¡ã³ããã³ã¹ãæ¯èŒç容æã ãšãããŠããŸãã
ãŸããCOBOLã¯æ°å€èšç®ã®ç²ŸåºŠãéåžžã«é«ãã巚倧ãªæ°å€ããŒã¿ã®åŠçãåŸæãšããŠããŸããããã¯ãéè¡ã®éèååŒãªã©ã粟床ãæ±ããããæ¥åã«ãããŠéåžžã«éå®ãããŸãã
ããã«ãCOBOLã¯é·ãæŽå²ãæã¡ãªãããè¿å¹Žã䜿ããç¶ããŠããŸããããã¯ããã®å ç¢ãªæ§èœãšäºææ§ã®é«ãã«ãããæ¢åã®ã·ã¹ãã ã«å¯Ÿããå¹ åºãæ¯æŽãå¯èœã ããã§ãã
1.3 COBOLãç¿åŸããã¡ãªãã
COBOLãç¿åŸããã¡ãªããã®1ã€ãšããŠãé«ã皌åçãšä¿¡é Œæ§ãæã€æ¥çã§ã®æ±äººãžã®å¯Ÿå¿ãæããããŸããç¹ã«éèã補é ãä¿éºãªã©ã®æ¥çã§ã¯ãCOBOLãå©çšããã·ã¹ãã ãå€ãååšãããããã«å¯Ÿããå°éã®ã¡ã³ããã³ã¹ãéçºè·ãå¿ èŠãšãããŠããŸãã
ãŸããCOBOLã¯ä»ã®ããã°ã©ãã³ã°èšèªãšã¯ç°ãªããç¬èªã®æèæ³ãæŠå¿µãç解ããããšã§ãããã°ã©ãã³ã°ã¹ãã«å šäœãé«ããããšãã§ããŸãã
ããã«ãCOBOLã¯ãã®ä¿¡é Œæ§ãšå ç¢æ§ãããéèŠãªããžãã¹ã·ã¹ãã ã§ã®äœ¿çšãç¶ããŠããŸãããã®ãããCOBOLã®ç¿åŸã¯ãã£ãªã¢ã®å®å®ã«ã€ãªããã§ãããã
1.4 COBOLã®æŽ»çšåé
COBOLã¯äž»ã«å€§èŠæš¡ãªããžãã¹ã¢ããªã±ãŒã·ã§ã³ã®éçºãªã©ãäŒæ¥ã®æ¥ååŠçã«åºãå©çšãããŠããŸããéè¡ãä¿éºäŒç€Ÿã補é æ¥ãªã©ã§ã¯ãCOBOLã«ãã倧éããŒã¿ã®åŠçããè€éãªããžãã¹ã«ãŒã«ã®ç®¡çãè¡ãããŠããŸãã
ãŸããæ¿åºé¢é£ã®ã·ã¹ãã ã§ã掻èºããŠããŸããäŸãã°ã瀟äŒä¿éãçšéãªã©ã®ã·ã¹ãã éçºã«COBOLã¯ãããåã®ããã«äœ¿çšãããŠããŸãããããã®ã·ã¹ãã ã§ã¯ãæ£ç¢ºã§ä¿¡é Œæ§ã®é«ãããŒã¿åŠçãæ±ãããããã®ããŒãºãCOBOLãæºãããŠããŸãã
ä»ã«ããèªç©ºå®å®ã®ç 究éçºãè»äºãå»çåéã®ã·ã¹ãã ãªã©ãCOBOLã¯å¹ åºãåéã§äœ¿çšãããŠããŸãã
2. COBOLã®åºæ¬æ§æãšã³ãŒã
COBOLãšã¯ãIn 1959幎ã«ç»å Žããããžãã¹çšã¢ããªã±ãŒã·ã§ã³ã®éçºã«ç¹åããããã°ã©ãã³ã°èšèªã§ããäž»ã«éèæ©é¢ã倧äŒæ¥ã®æ¥åç³»ã·ã¹ãã ã§äœ¿ãããŠããããã®ã³ãŒãéã¯éåžžã«å·šå€§ã§ããä»åã¯ãã®åºæ¬æ§æãšã³ãŒãã解説ããŠãããŸãã
COBOLã¯ããã®å¯èªæ§ã®é«ãããåå¿è ã«ãåãçµã¿ãããããŸãå ç¢ãªããã°ã©ã ãäœãããšãå¯èœã§ãããã ããã®ç¹åŸŽãšãªãè±æã«è¿ãããã°ã©ã ã®æžãæ¹ã¯ãä»ã®ããã°ã©ãã³ã°èšèªãšã¯å°ã ç°ãªããŸãã
ã§ã¯ãå ·äœçã«èŠãŠãããŸãããã
2.1 COBOLã®åºæ¬çãªããã°ã©ã ã®æ§é
ãŸãã¯ãCOBOLããã°ã©ãã³ã°ã®åºæ¬çãªæ§é ããèŠãŠãããŸããããCOBOLããã°ã©ã ã¯IDENTIFICATION DIVISION, ENVIRONMENT DIVISION, DATA DIVISION, PROCEDURE DIVISIONã®4ã€ã®åºåã«åãããŸãã
IDENTIFICATION DIVISIONã¯ãããã°ã©ã ã®ååã説æãæžãéšåã§ããENVIRONMENT DIVISIONã¯ããã°ã©ã ã®éè¡ç°å¢ãèšè¿°ããŸããDATA DIVISIONã§ã¯ãããã°ã©ã ã§äœ¿çšããããŒã¿é ç®ãå®çŸ©ããããã®éšåã§ãã
æåŸã«ãPROCEDURE DIVISIONã¯ãããŒã¿ãã©ã®ããã«åŠçããããå ·äœçã«æžãéšåã§ãããã°ã©ã ã®äž»èŠãªåŠçãèšãããŸãã
2.2 COBOLã®åºæ¬çãªæ§æ
次ã«ãCOBOLã®åºæ¬çãªæ§æãèŠãŠãããŸãããã
ããšãã°ãããŒã¿ã®ç§»åãè¡ãMOVEæãæ¡ä»¶åå²ãè¡ãIFæãç¹°ãè¿ãåŠçãè¡ãPERFORMæãªã©ãããããããã䜿ãããªãããšã§å€æ§ãªåŠçãè¡ãããšãã§ããŸãã
ç¹åŸŽçãªã®ã¯ãè±æèªæ³ã«æºããèšè¿°ãå¯èœã§ããããšã§ãäŸãã°ããMOVE A TO Bãã®ããã«çŽèš³ãããšãAãBã«ç§»åããããšãªããããªãçŽæçãªã³ãŒããæžãããšãã§ããŸãã
2.3 COBOLã§ã®å€æ°ãšããŒã¿å
次ã«ãCOBOLã§ã®å€æ°ãšããŒã¿åã«ã€ããŠèª¬æããŸããå€æ°ãšã¯ãããŒã¿ãæ ŒçŽãããã㮔箱”ã®ãããªãã®ã§ããã®ä»²éãšããŠããŒã¿åããããŸããCOBOLã«ã¯æ°å€åãã¢ã«ãã¡ãããåãçåœåãªã©ã®åºæ¬çãªããŒã¿åãååšããŸãã
ãŸããå€æ°ãå®çŸ©ããéã«ã¯ãDATA DIVISIONå ã§ã01 å€æ°å PICTURE 圢åŒãããšãã圢åŒã§èšè¿°ããŸããå ·äœçã«ã¯ãã01 NUMBER PICTURE 9(5).ãã§5æ¡ã®æŽæ°åã®å€æ° NUMBER ãå®çŸ©ã§ããŸãã
ãã®ããã«ãCOBOLã®å€æ°ãšããŒã¿åã®äœ¿çšæ¹æ³ã¯ä»ã®ããã°ã©ãã³ã°èšèªãšæ¯èŒãããšå°ã ç¹æ®ã§ãããç解ããŠäœ¿ãããªãããšãã§ããã°ããã質ã®é«ãããã°ã©ã ãäœæããããšãå¯èœãšãªããŸãã
2.4 COBOLã®äžè¬çãªã³ãŒãã£ã³ã°äŸ
æåŸã«ãäžè¬çãªCOBOLã®ã³ãŒãã£ã³ã°äŸã玹ä»ããŸãã以äžã¯ããŠãŒã¶ãŒããæŽæ°ã2ã€å ¥åãããã®åèšã衚瀺ããã·ã³ãã«ãªCOBOLããã°ã©ã ã§ãã
IDENTIFICATION DIVISION.
PROGRAM-ID.
ENVIRONMENT DIVISION.
DATA DIVISION.
PROCEDURE DIVISION.
ACCEPT NUM1.
ACCEPT NUM2.
COMPUTE TOTAL = NUM1 + NUM2.
DISPLAY "TOTAL IS" TOTAL.
STOP RUN.
äžèšã®ããã°ã©ã ã§ã¯ãACCEPTæã§ãŠãŒã¶ãŒããã®å ¥åãåãåããCOMPUTEæã§èšç®ãè¡ããDISPLAYæã§çµæãåºåãããšããåŠçãè¡ããŸãã
ãããCOBOLã®åºæ¬çãªããã°ã©ã ã®æ§é ãšåŠçã®æµãã§ããåããŠèŠããšå°ã ç¹æ®ã«èŠãããããããŸãããããã®èšè¿°ã®æçããšåŒ·åºãã¯ãå€æ§ãªããžãã¹ã¢ããªã±ãŒã·ã§ã³ã®éçºã§æŽ»èºããŸãã
3. COBOLç¬åŠã®ã¹ããã
COBOLã®ç¬åŠã«ã¯ãäžå®ã®ããã»ã¹ãçµãŠåŠç¿ãé²ããããšãçæ³çã§ãã以äžã«ãæåãžã®éçãæäŸããã¹ãããã詳ãã説æããŸãã
ãã®ã¹ããããé ã«ãã©ãããšã§ãCOBOLã®ç¥èãå¹ççã«ããã€ç解ãããã身ã«ã€ããããšãå¯èœãšãªããŸãã
ç¬åŠãšã¯ãããèšç»æ§ãšã¹ããããã€ã¹ãããã®ã¢ãããŒããéèŠãšãªããŸãã
3.1 COBOLã®åºç€ãç解ãã
ãŸãã¯ããã«ãCOBOLã®åºç€ãç解ããããšã倧åã§ããCOBOLã®ããŒã¿ã¿ã€ããå¶åŸ¡æ§é ãæ§æãªã©ãåºæ¬çãªéšåããåŠã³ãŸãããã
åå¿è åãã®ææããªã³ã©ã€ã³ã®è³æãå©çšããããšã§ãèªåã®ããŒã¹ã§ç解ãæ·±ããããšãå¯èœã§ãã
ãŸããåºç€ç¥èãçå®ã«ä¿®åŸããããšã§ã次ã®ã¹ãããã«é²ãæºåãæŽããŸãã
3.2 COBOLã®ã³ãŒãã£ã³ã°ãç·Žç¿ãã
åºç€ç¥èãæŽã£ããã次ã«ã³ãŒããæžãç·Žç¿ãå§ããŠãããŸããããã§ã¯ãå®éã«æãåãããªããåŠã¶ããšã§ãç解ãããæ·±ããŠãããŸãããã
åãã¯ã·ã³ãã«ãªããã°ã©ã ããå§ããåŸã ã«é£æ床ãäžããŠãããšè¯ãã§ãããããã®éçšã§ééããåé¡ã解決ããŠããããšã§ãèª naturally and efficientlyã«å匷ãè²ã£ãŠãããŸãã
åé¡ã解決ããã¹ãã«ã¯ãããã°ã©ãã³ã°ã«ãããéèŠãªèœåã®äžã€ãªã®ã§ããã²ç·Žç¿ããŠãããããšããã§ãã
3.3 COBOLã®é«åºŠãªãã¯ããã¯ãåŠã¶
åºç€çãªç¥èãšã¹ãã«ã身ã«ã€ããããæŽã«é«åºŠãªãã¯ããã¯ãåŠã¶ææã«æ¥ããšããããšã§ããCOBOLã¯è±å¯ãªæ©èœãåããŠããŸãã®ã§ãããã§ã¯ãã®å é²çãªéšåã«è§ŠããŠãããŸãã
ããŒã¿ããŒã¹ãšã®é£æºããããã¯ãŒã¯éä¿¡ãªã©ãããå¹æçãªããã°ã©ã ãæžãããã®ãã¯ããã¯ãåŠãŒããšåªåããŸãããã
ãã®ã¹ãããã®åŠç¿ã¯ãèªèº«ã®ã³ãŒãã£ã³ã°ã¹ãã«ãäžæ®µãšäžããããšã«ç¹ãããŸãã
3.4 èªèº«ã®ã¹ãã«ã¢ããã®ããã®ã«ãŒãã£ã³ãäœã
æåŸã«éèŠãªã®ã¯ãæ¥ã ã®åŠç¿ã®ã«ãŒãã£ã³ãäœãããšã§ããCOBOLã¯è€éãªããã°ã©ãã³ã°èšèªã§ãããå®æçãªåŸ©ç¿ãšç·Žç¿ãå¿ èŠã§ãã
ç¹å®ã®æéãèšããŠå埩緎ç¿ããããšã§ãã¹ãã«ã®å®çãé«ããæ°ããªç¥èã®åžåã«ãã€ãªãããŸãã
ãããŠããã®ã«ãŒãã³æ§ãæã€ããšããé·æéã«æž¡ã£ãŠCOBOLãç¬åŠããããã®æç¶åã圢æããŸãã
4. COBOLç¬åŠã®ããã®ãªãœãŒã¹
COBOLã®ããã°ã©ãã³ã°ã¹ãã«ãç¬åŠã§ç¿åŸããããã«ã¯é©åãªãªãœãŒã¹ãäžå¯æ¬ ã§ãã以äžã«ãåå¿è ã§ãç解ããããææããããã«æ·±ãåŠã³ããäžã»äžçŽè åãã®è§£èª¬æžãããã«ã¯COBOLã³ãã¥ããã£ãªã©ãã³ãŒãã£ã³ã°åãåäžãããããã®è³æºã玹ä»ããŸãã
4.1 ããããã®ãªã³ã©ã€ã³ææ
ãªã³ã©ã€ã³ææã¯ãèªå® ããªãã£ã¹ã§åŠã¹ãæ軜ããšã©ã€ãã©ãªã®å å®ãé åã§ããCourseraãedXã§ã¯ãããã®è¬åž«ãæå°ããCOBOLã®åºç€ããå¿çšãŸã§ãåŠã¹ãŸãããŸããUdemyã§ã¯ãåå¿è ããäžçŽè ãŸã§å€æ°ã®COBOLè¬åº§ãããã®ã§ãèªèº«ã®ã¹ãã«ã¬ãã«ãç®æãæ¹åæ§ã«åãããŠéžã¶ããšãã§ããŸãã
ãŸãããããäžã®ç¡æææãšããŠãW3SchoolsãTutorialspointãããããã§ãã
4.2 COBOLã®è§£èª¬æžç±
ãŸããèªåã®ããŒã¹ã§ãã£ãããšåŠã³ããæ¹ã«ã¯ã解説æžç±ãæé©ã§ãããªã¢ã«ã¿ã€ã æ§ã¯ãããŸããããæéããããŠæ·±ãç解ããã«ã¯æé©ã§ãã“Beginning COBOL for Programmers”ã“Murach’s Mainframe COBOL”ã¯åå¿è ã§ãåãçµã¿ãããè¯æžã§ãã
é¡æãšããŠçã®äºäŸãåãå ¥ããªãã解説ããŠãã“COBOL for the 21st Century”ã¯ãçŸå Žã§å³æŠåãšãªãæè¡ãåŠã³ããæ¹ã«ãŽã£ããã§ãã
4.3 COBOLé¢é£ã®ãŠã§ããµã€ããšããã°
COBOLã®æ å ±ãæ¥ã è¿œãæ±ããããªãããŠã§ããµã€ããããã°ãæå¹ã§ããRedditã®COBOLã³ãã¥ããã£ãStackOverflowã§ã¯ãäžçäžã®äººã ãæ±ããåé¡ãšè§£æ±ºçãå ±æãããŠããŸãã
ãŸããå°é家ãå·çããããã°ãåèã«ãªããŸãã“Pro COBOL programming”ããã°ãªã©ã§ã¯ãå°é家ã®èŠç¹ããèŠãCOBOLã®ææ°æ å ±ãåŠã¶ããšãã§ããŸãã
4.4 COBOLã®åŠç¿ã³ãã¥ããã£
æåŸã«ãç¬åŠã ãã§ãªãCOBOLåŠç¿è ãšäº€æµããããšãéèŠã§ããããã§æŽ»çšãããã®ãåŠç¿ã³ãã¥ããã£ã§ããMeetupãDiscordã«ã¯ãCOBOLã«èå³ãæã€äººã ãéãã°ã«ãŒããååšããŸããããã§ã¯ãåå¿è ã®çå解決ããå°éçãªè°è«ãŸã§ãåèªã®åé¡è§£æ±ºã«åœ¹ç«ã€æ å ±ãåŸãããŸãã
èªåäžäººã ãã§ãªããä»ã®COBOLåŠç¿è ãšååããªããåŠãã§ããããšã§ãæŽãªãã¹ãã«ã¢ãããå³ãããšãå¯èœã§ãã
5. COBOLç¬åŠã®ãã£ã¬ã³ãžãšè§£æ±ºç
ç¬èªã«COBOLãåŠãŒããšæ±ºå¿ããæ¹ã«å¯Ÿãããã®ã»ã¯ã·ã§ã³ã§ã¯COBOLç¬åŠã®ãã£ã¬ã³ãžãšãããå æããããã®è§£æ±ºçã«ã€ããŠæ€èšŒããŸãã
ããªããåç¬ã§COBOLãåŠã¶ãšãã«ééããå¯èœæ§ã®ããåé¡ãšããããã«å¹æçã«å¯ŸåŠããããã®æŠç¥ã«ã€ããŠè©³ããèå¯ããŸãã
COBOLåŠç¿ã«ãããäžè¬çãªèª€è§£ã«ãäžç·ã«è§ŠããŠãããªãããããã®èª€è§£ã®åœ±é¿ãåããããšãªããããªãèªèº«ã®åŠç¿æ è¡ãæ倧éã«æŽ»çšããããšãã§ããããã«ããŸãã
5.1 COBOLç¬åŠã®é£æ床
COBOLç¬åŠã®é£æ床ã¯åã ã®èæ¯ãšçµéšã«å€§ããå·Šå³ãããŸãã
COBOLã¯äžéšã®æ¥çã§åºã䜿ããç¶ããŠããŸãããããã¯å€ãã®å ŽåãäŒçµ±çãªããžãã¹ç°å¢ã§ããäžè¬çã«äœ¿çšãããŠããŸãããã®ãããæ°ãããã®èšèªãåŠãŒããšãã人ã ãçŽé¢ããå¯èœæ§ã®ããæ倧ã®é害ã¯ãCOBOLãä»ã®ãã£ãšäžè¬çã«äœ¿çšãããŠããèšèªãšã¯ããç°ãªããã©ãã€ã ãšæ§æãæã£ãŠããããšã§ãã
ã§ããã匷調ãããã®ã¯COBOLãè¯ãçµç¹åãããŠããŠèªã¿ãããèšèªã§ãããšããäºå®ã§ãããã®ç¹æ§ã¯ãåªããæç§æžãææãšçµã¿åãããã°ãç¬åŠè ã§ãCOBOLã®åŠç¿ã¯å åã«éæå¯èœã§ããããšãæå³ããŸãã
5.2 COBOLã®åŠç¿ã«ãããäžè¬çãªåé¡ç¹
COBOLã®ç¬åŠã§ã¯ãç¹å®ã®åé¡ç¹ãããå ±åãããŸãããããã¯äž»ã«ãè³æºã®äžè¶³ãé©åãªç·Žç¿ç°å¢ã®æ¬ åŠããããŠåŠç¿ã®é²è¡ã«äŒŽãã¢ãããŒã·ã§ã³ç¶æã®èª²é¡ã§ãã
ãããããããã®èª²é¡ã¯å šãŠè§£æ±ºå¯èœã§ãã COBOLã®åŠç¿è³æºã¯ã€ã³ã¿ãŒãããäžã«åºãã£ãŠããŸããäœãèŠã€ããã©ããæ¢ãããç¥ã£ãŠããã ãã§ãç¡æãŸãã¯äœäŸ¡æ Œã®è³ªã®é«ãææãèŠã€ããããšãã§ããŸãã
ãŸããã¢ãã³ãªCOBOLã®éçºç°å¢ã¯ç¡æã§å©çšå¯èœã§ãããã¢ãããŒã·ã§ã³ã¯å ·äœçãªç®æšãèšå®ãããã®éæãç®æããŠèªåèªèº«ã«å ±é ¬ãèšå®ããããšã§ç¶æããããšãå¯èœã§ãã
5.3 COBOLåŠç¿ã®ã¢ãããŒã·ã§ã³ãä¿ã€æ¹æ³
ã¢ãããŒã·ã§ã³ã¯åŠç¿ã®æåã«äžå¯æ¬ ã§ããç¹ã«èªåŠç¿ã§ã¯ãé·æéã«ãããåŠç¿ã«åãçµãããã®ã¢ãããŒã·ã§ã³ãç¶æããããšãéèŠã§ãã
ç®æšãèšå®ãããã®éæãç®æãããšã¯ãã¢ãããŒã·ã§ã³ãç¶æããæå¹ãªæ¹æ³ã§ããããªããäœãéæãããã®ãããããäœæ éèŠããç解ããããšã¯ãé²è¡ãç¶ããããã®åŒ·åãªåæ©ä»ãã«ãªããŸãã
ãŸããæåäœéšãå®æçã«ç©ã¿éããããšã§ãèªä¿¡ãšã¢ãããŒã·ã§ã³ãä¿ã€ããšãã§ããŸãããããããã°ã©ãã³ã°ã«ãããå°ããªãããžã§ã¯ããèªåã§å®æãããããšã§ãã£ãããåé¡ã解決ããããã®æ°ããªææ³ãåŠã¶ããšã§ãã£ããããã®ã§ãã
5.4 COBOLç¬åŠã«å¯Ÿããäžè¬çãªèª€è§£ãšããã®è§£æ¶
COBOLç¬åŠã«ã€ããŠã®äžè¬çãªèª€è§£ã®äžã€ã¯ããã®èšèªããå€ãããŸãã¯ãå»ãããèšèªã§ãããšããèãæ¹ã§ããããããããã¯å šãäºå®ã§ã¯ãããŸããã
çŸåšã§ãå€ãã®å€§äŒæ¥ãæ¿åºæ©é¢ã¯ãCOBOLã§æžãããã¢ããªã±ãŒã·ã§ã³ã«å€§å¹ ã«äŸåããŠããŸãããã®ãããªçµç¹ã§ã¯COBOLã®ã¹ãã«ãæã€å°é家ãå¿ èŠãšããŠããããã®ããã«è¯å¥œãªå ±é ¬ãæäŸããŠããŸãã
ãŸããCOBOLã¯ãã®ååã瀺ãéããããžãã¹ãªãªãšã³ããããªèšèªã§ããããã¯éèãä¿éºã補é æ¥ãªã©ãããžãã¹ãéèŠãªåœ¹å²ãæããå šãŠã®æ¥çã§äœ¿çšãããŠããŸãããããã£ãŠãCOBOLãç解ããå©çšã§ããã¹ãã«ãæã€ããšã¯ããããã®æ¥çã§ã®è·å Žã§ç«¶äºåªäœã確ä¿ãã匷åãªããŒã«ãšãªããŸãã
6. COBOLã¹ãã«ã®ç¬åŠåŸã®æŽ»çš
COBOLãç¬åŠã§åŠã³çµããåŸã¯ããã®ã¹ãã«ãã©ã掻çšããããåãããŸããããã§ã¯ãCOBOLã¹ãã«ã®æŽ»çšæ¹æ³ã«ã€ããŠå ·äœçã«æ¢ããŸãã
è³æ ŒååŸããã£ãªã¢ãã¹ã®éžæããããã掻ãããä»äºã®æ¢ãæ¹ãªã©ãããŸããŸãªèŠ³ç¹ãã解説ããŸããããã«ãCOBOLã¹ãã«ãããããæ°ããå¯èœæ§ã«ã€ããŠã觊ããŠãããŸãã
ããŠãCOBOLãç¬åŠã§ç¿åŸããããªãã次ã«èããã¹ãããšã¯äœããããããèŠãŠãããŸãããã
6.1 COBOLè³æ Œã®ååŸ
ãŸããCOBOLã¹ãã«ã®æŽ»çšãšããŠèããããã®ãCOBOLè³æ Œã®ååŸã§ããç¬åŠã§COBOLãåŠãã ãªãã°ããã®ã¹ãã«ã蚌æããè³æ Œãåãããšã§ãæŽãªãèªä¿¡ãåŸãããšãã§ããŸãã
è³æ Œã¯èªèº«ã®ã¹ãã«ã¬ãã«ã蚌æããã ãã§ãªããå°±è·ã»è»¢è·æŽ»åã§ã匷åãªæŠåšã«ãªããŸããç¹ã«å€ããã䜿çšããç¶ããŠããCOBOLã«é¢ããè³æ Œã¯ãçµéšã»ä¿¡çšã»å®çžŸãåãããããžãã¹ã®å Žã§ã¯ã倧ãã«äŸ¡å€ãæã€ãšèšããŸãã
ããããè³æ ŒãååŸããããšèããŠããæ¹ã¯ããã¡ããšããåŠç¿èšç»ãç«ãŠãç®æšèšå®ããã£ãããšè¡ããŸãããã
6.2 COBOLã掻çšãããã£ãªã¢ãã¹
次ã«ãCOBOLã掻çšãããã£ãªã¢ãã¹ã«ã€ããŠèããŠã¿ãŸããããCOBOLã¯ãç¹ã«éè¡ãä¿éºãªã©ã倧èŠæš¡ãªã·ã¹ãã ãæã€äŒæ¥ã§äœ¿çšãããŠããŸãã
ãã®ãããCOBOLãç¬åŠã§åŠã¹ãããªãã¯ããããã®åéã§åãããšãèŠéã«å ¥ãããšè¯ãã§ããããããã«ãCOBOLã®ã¹ãã«ã¯ããããžã§ã¯ããããŒãžã£ãŒãã·ã¹ãã ãšã³ãžãã¢ãã·ã¹ãã ã³ã³ãµã«ã¿ã³ããªã©ã«ãå¿ èŠäžå¯æ¬ ã§ãã
ãããã®è·çš®ã¯ããããé«åå ¥ã§ç¥ãããŠãããCOBOLã¹ãã«ãæã€ããšã§å€æ§ãªãã£ãªã¢ãã¹ãéããå¯èœæ§ããããŸãã
6.3 COBOLã¹ãã«ã掻ããä»äº
COBOLã¹ãã«ã掻ããä»äºãšããã°ãæãäžè¬çãªã®ãããã°ã©ããŒãã·ã¹ãã ãšã³ãžãã¢ã§ãããããã®è·çš®ã§ã¯ãæ¥ã COBOLãçšããéçºãä¿å®ãè¡ãããŠããŸãã
ãããããã以å€ã«ãCOBOLã¹ãã«ã¯åœ¹ç«ã€å Žé¢ããããããããŸããããšãã°ãã¢ããªã±ãŒã·ã§ã³ã³ã³ãµã«ã¿ã³ãããããžã§ã¯ããããŒãžã£ãŒãªã©ã®è·çš®ã§ã¯ãCOBOLã®ç¥èã¯å€§ããªåŒ·ã¿ãšãªãåŸãŸãã
ãããã®è·çš®ã§ã¯ãCOBOLãåºã«ããã·ã¹ãã ã®å šäœåãææ¡ããå ·äœçãªæ¹åçãæ¹åæ§ãææ¡ã§ããèœåãæ±ããããããã§ãã
6.4 COBOLã®ç¿åŸã§éãããæ°ããå¯èœæ§
æåŸã«ãCOBOLã®ç¿åŸãéãæ°ããå¯èœæ§ã«ã€ããŠèããŠã¿ãŸããããå€ãã®äººã«ãšã£ãŠCOBOLã¯å€ãèšèªãšããã€ã¡ãŒãžã匷ããããããŸããããããããã®åé¢ããã®ã¹ãã«ã¯äŸç¶ãšããŠé«ãè©äŸ¡ãããŠããŸãã
å€ãã®æ¢åã·ã¹ãã ããããŸã§ã®é·ãéã«ããã£ãŠCOBOLã§éçºãããŠããŸããããããã®ã·ã¹ãã ãæ±ãããã«ã¯ãCOBOLã®ã¹ãã«ãäžå¯æ¬ ã§ãã
COBOLãç¬åŠã§åŠã¶ããšã§ãå€ãããã®å€§èŠæš¡ã·ã¹ãã ãç解ãããã®ã¡ã³ããã³ã¹ãæ¹ä¿®ã«æºããããšãå¯èœãšãªããããã¯æ°ããªéãåãéãäžã€ã®æ¹æ³ã«ãªãã§ãããã