![\"Unix](\"\/wp-content\/uploads\/2020\/01\/1b3a3bdeb0400f3b34d5cd6964a48010.jpg\")
<\/p>\n2020-ci il Unix \u00fc\u00e7\u00fcn \u0259lam\u0259tdar bir ildir: ilin \u0259vv\u0259lind\u0259 orijinal \u0259m\u0259liyyat sisteminin 50 ya\u015f\u0131 tamam oldu. Unix zaman\u0131, eyni zamanda «epok tarixl\u0259ri» olaraq da tan\u0131nan, 1 yanvar 1970-ci ild\u0259n ke\u00e7\u0259n saniy\u0259l\u0259rin say\u0131d\u0131r. B\u0259s Unix-in yar\u0131m \u0259srlik yubileyi il\u0259 ba\u011fl\u0131 n\u00fcv\u0259ni inki\u015faf etdir\u0259nl\u0259ri n\u0259 narahat edir?<\/p>\n
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B\u0259zi erk\u0259n Unix inki\u015faflar\u0131n\u0131n r\u0259smi «epoka»n\u0131n ba\u015flanmas\u0131ndan \u0259vv\u0259l h\u0259yata ke\u00e7irilm\u0259sin\u0259 baxmayaraq, 1 yanvar 1970-ci il POSIX-in zaman\u0131ndak\u0131 s\u0131f\u0131r n\u00f6qt\u0259sidir. Buna g\u00f6r\u0259 d\u0259 1 yanvar 2020-ci ild\u0259n etibar\u0259n platforma r\u0259smi olaraq tam 50 il ya\u015fad\u0131.<\/p>\n
Vaxt <\/strong>Unix'in insan zaman\u0131na k\u0131yas\u0131<\/strong><\/p>\n \u0130nsan vaxt\u0131 bax\u0131m\u0131ndan 50 il b\u00f6y\u00fck bir m\u00fcdd\u0259tdir. Unix vaxt\u0131 bax\u0131m\u0131ndan is\u0259 50 il d\u0259h\u015f\u0259tli bir \u015fey deyil, 43 il d\u0259 eyni d\u0259r\u0259c\u0259d\u0259 \u0259h\u0259miyy\u0259tlidir. Unix sisteml\u0259ri (Linux daxil olmaqla) tarix v\u0259 zaman d\u0259y\u0259rl\u0259rini 1970-01-01 00:00:00 UTC-d\u0259n ke\u00e7\u0259n saniy\u0259l\u0259rin say\u0131 kimi saxlay\u0131r, 32 bitlik qeydiyyatla. O vaxtdan b\u0259ri n\u0259 q\u0259d\u0259r saniy\u0259 ke\u00e7diyini m\u00fc\u0259yy\u0259nl\u0259\u015fdirm\u0259k v\u0259 dolay\u0131s\u0131yla Unix-in indiki d\u0259y\u0259rini \u00f6yr\u0259nm\u0259k \u00fc\u00e7\u00fcn a\u015fa\u011f\u0131dak\u0131 \u0259mri icra ed\u0259 bil\u0259rsiniz:<\/p>\n $ date +%s<\/p>\n 1576883876<\/p>\n date komutundaki %s arg\u00fcman\u0131, ge\u00e7erli tarih ve saati 1970-01-01'den itibaren ge\u00e7en saniye say\u0131s\u0131 olarak g\u00f6sterir.<\/p>\n Sistemler Unix'in ne kadar maksimum tarihi saklayabilir? <\/strong>Unix?<\/strong><\/p>\n Unix sisteminin ne kadar s\u00fcre tutabilece\u011fini anlamak i\u00e7in, 32 bitlik alan\u0131n kapasitesini de\u011ferlendirmek gerekir. Bu \u015f\u00f6yle hesaplanabilir:<\/p>\n $ echo '2^32' | bc<\/p>\n 4294967296<\/p>\n Ancak, Unix negatif say\u0131lar\u0131n saklanmas\u0131n\u0131 sa\u011flad\u0131\u011f\u0131 i\u00e7in, bir bit i\u015faret i\u00e7in ayr\u0131lm\u0131\u015ft\u0131r, bu da zaman de\u011ferini \u015f\u00f6yle azalt\u0131r:<\/p>\n $ echo '2^31' | bc<\/p>\n 2147483648<\/p>\n V\u0259 Unix-in s\u0131ralamas\u0131 0-dan ba\u015flad\u0131\u011f\u0131 \u00fc\u00e7\u00fcn bu, 2 147 483 648 d\u0259y\u0259ri oldu\u011fumuz dem\u0259kdir, lakin \u0259n b\u00f6y\u00fck d\u0259y\u0259r 2 147 483 647-dir \u2014 Unix tarix v\u0259 zaman d\u0259y\u0259rl\u0259ri bu r\u0259q\u0259md\u0259n yuxar\u0131 ola bilm\u0259z. Avtomobilin odometrinin 999 999 kilometrd\u0259n \u00e7oxunu g\u00f6st\u0259rm\u0259si m\u00fcmk\u00fcn olmad\u0131\u011f\u0131 kimi \u2014 1 \u0259lav\u0259 ets\u0259niz, d\u0259y\u0259r s\u0131f\u0131rlanacaq.<\/p>\n Bir y\u0131l ka\u00e7 saniye s\u00fcrer?<\/strong><\/p>\n Bir y\u0131ldaki saniye say\u0131s\u0131n\u0131 \u015fu \u015fekilde hesaplayabilirsiniz:<\/p>\n $ expr 24 * 60 * 60 * 365<\/p>\n 31536000<\/p>\n Art\u0131k y\u0131l oldu\u011funda bir g\u00fcn daha eklenir:<\/p>\n $ expr 24 * 60 * 60 * 366<\/p>\n 31622400<\/p>\n Unix, 50. do\u011fum g\u00fcn\u00fcn\u00fc nas\u0131l g\u00f6steriyor?<\/strong><\/p>\n 1 Ocak 2020'de sabah 12:00'de zaman 1577836800 olacakt\u0131r. Hesaplama biraz karma\u015f\u0131kla\u015f\u0131r \u00e7\u00fcnk\u00fc art\u0131k y\u0131llar\u0131 dikkate almak gerekir. Unix d\u00f6neminin ba\u015flang\u0131c\u0131ndan bu yana 1972'den 2016'ya kadar 12 b\u00f6yle y\u0131l ge\u00e7mi\u015ftir. Yani, 38 normal y\u0131l ge\u00e7mi\u015ftir.<\/p>\n \u0130\u015fte ge\u00e7en 50 y\u0131l i\u00e7indeki saniyeleri hesaplamak i\u00e7in expr komutunun g\u00f6r\u00fcn\u00fcm\u00fc:<\/p>\n $ expr 24 * 60 * 60 * 365 * 38 + 24 * 60 * 60 * 366 * 12<\/p>\n 1577836800<\/p>\n Ya da daha \u00f6nce yap\u0131lan hesaplamalarla birlikte:<\/p>\n $ expr 31536000 * 38 + 31622400 * 12<\/p>\n 1577836800<\/p>\n Bu zaman qeyd etm\u0259 \u00fcsulu, Unix sisteml\u0259rini Y2K problemin\u0259 qar\u015f\u0131 d\u00f6z\u00fcml\u00fc etdi ki, bu da insanlar\u0131n 1999-cu ilin sonunda 2000-ci il ke\u00e7idinin komp\u00fcter sisteml\u0259rin\u0259 z\u0259r\u0259r ver\u0259 bil\u0259c\u0259yind\u0259n narahat olmalar\u0131na s\u0259b\u0259b oldu. Qar\u015f\u0131la\u015fd\u0131qlar\u0131 \u00e7\u0259tinlikl\u0259r g\u00f6zl\u0259nil\u0259nd\u0259n \u00e7ox az oldu. H\u0259qiq\u0259t\u0259n d\u0259, yaln\u0131z iki r\u0259q\u0259mli formatda ill\u0259ri qeyd ed\u0259n t\u0259tbiql\u0259r tarixl\u0259rin s\u0131f\u0131rlanmas\u0131 il\u0259 \u00fczl\u0259\u015fdil\u0259r. Bir \u00e7ox inki\u015faf etdirici, t\u0259tbiql\u0259rinin Y2K problemin\u0259 t\u0259sir etm\u0259m\u0259si \u00fc\u00e7\u00fcn \u0259lav\u0259 i\u015fl\u0259r g\u00f6rd\u00fc.<\/p>\n Zaman <\/strong>Unix n\u0259 vaxt probleml\u0259rl\u0259 qar\u015f\u0131la\u015facaq?<\/strong><\/p>\n Ox\u015far \u00e7\u0259tinlikl\u0259r, yuxar\u0131da qeyd olunan formatda saxlan\u0131lan tarixl\u0259rin 32-bit m\u0259kan\u0131n\u0131 a\u015faca\u011f\u0131 2038-ci ild\u0259n \u0259vv\u0259l Unix sisteml\u0259rini g\u00f6zl\u0259mir. H\u0259l\u0259 18 il qal\u0131b, amma n\u00fcv\u0259nin inki\u015faf etdiricil\u0259ri art\u0131q g\u0259l\u0259c\u0259k \u00e7axna\u015fmalar\u0131 qar\u015f\u0131s\u0131n\u0131 almaq \u00fc\u00e7\u00fcn \u00e7al\u0131\u015f\u0131rlar.<\/p>\n 2038-ci il problemi b\u0259z\u0259n Y2K38 problemi olaraq adland\u0131r\u0131l\u0131r. \u018fg\u0259r bu problem 19 yanvar 2038-ci il, \u00e7\u0259r\u015f\u0259nb\u0259 ax\u015fam\u0131 g\u00fcn\u00fcn\u0259 q\u0259d\u0259r h\u0259ll edilm\u0259s\u0259, sonra sisteml\u0259r 1901-ci ilin g\u0259ldiyini d\u00fc\u015f\u00fcn\u0259 bil\u0259rl\u0259r. Bu problemin h\u0259ll yollar\u0131ndan biri tarix v\u0259 zaman m\u0259lumatlar\u0131n\u0131n 64-bitlik t\u0259qdimat\u0131na ke\u00e7m\u0259kdir. B\u0259zil\u0259ri bunun daha da m\u00fcr\u0259kk\u0259b olaca\u011f\u0131na inan\u0131r.<\/p>\n![\"Unix](\"\/wp-content\/uploads\/2020\/01\/aba69e769edb987923b060b6e32f9a00.jpg\")
<\/p>\n![\"Unix](\"\/wp-content\/uploads\/2020\/01\/a720be1bfca58df09540785bf66f556d.jpg\")
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