gitの裏側をさぐる

新人研修で喋った内容です

Transcript

1. 1
   ͷཪଆΛ͙͞Δ
   ΞϓϦνʔϜ த઒ສᣦಸ
   

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2. 2
   Marina Nakagawa
   @marina10172013
   ೔ຊܦࡁ৽ฉࣾͷiOSΤϯδχΞ
   ిࢠ൛ΞϓϦɼࢴ໘ϏϡʔΞʔΞϓϦͷ։ൃ
   

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3. 3
   git࢖͑ΔΑ͏ʹͳ͖͚ͬͯͨͲɾɾɾ
   தͰԿ͕ى͍ͬͯ͜Δͷ͔Θ͔Βͳ͍ਓ
   ର৅ऀ
   ͋ͷ਺ࣈͱจࣈͷཏྻ͕Կ͔Θ͔Βͳ͍ਓ
   

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4. 4
   ϋογϡ஋ΛݟͯΈΑ͏
   SHA-̍ϋογϡ஋
   $git log
   ϑΝΠϧ಺༰ʹج͍ͮͯܭࢉ͞ΕΔ160Ϗοτʹ
   ू໿͞ΕΔϥϯμϜͳ஋
   

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5. 5
   Ͳ͏΍ͬͯόʔδϣϯ؅ཧ͕Ͱ͖Δͷʁ
   

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6. 6
   ͨΊͯ͠ΈΑ͏
   $mkdir test-git
   σΟϨΫτϦΛ࡞Δ
   $cd test-git
   test-gitͷதʹ͸͍Δ
   $ls -A
   தͷϑΥϧμΛݟΔ
   ·ͩԿ΋ೖ͍ͬͯ·ͤΜ
   

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7. 7
   ͨΊͯ͠ΈΑ͏
   $git init
   Initialized empty Git repository in /Users/nakagawa/Projects/test-git/.git/
   GitΛ࢖͑ΔΑ͏ʹ͢Δ
   $ls -A
   ϑΥϧμͷத਎ΛݟΔ
   .gitϑΝΠϧ͕Ͱ͖͍ͯ·͢
   

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8. 8
   ͨΊͯ͠ΈΑ͏
   $ls .git
   HEAD config hooks objects
   branches description info refs
   .gitϑΝΠϧͷத਎ΛݟͯΈ·͠ΐ͏
   

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9. 9
   ৽͘͠ϑΝΠϧΛ࡞ͬͯaddͯ͠ΈΑ͏
   $echo 'hello' > README
   READMEϑΝΠϧΛͭ͘Γ·͢
   $git add README
   READMEϑΝΠϧΛadd͠·͢
   Index͕௥Ճ͞Εͨʂ
   $ls -A .git

   HEAD config hooks info refs
   branches description index objects
   .gitͷϑΝΠϧͷத਎ΛݟͯΈΔ
   

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10. 10
    ͓·͚
    .git/indexͬͯԿʁ
    

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11. 11
    .git/indexͬͯͳΜͩΖ͏ʁ
    $git ls-files -s
    ΠϯσοΫεͷΦϒδΣΫτ໊ɺmode bitsɺstage number Λදࣔͤ͞ΔίϚϯυΛ࢖͏
    ϑΝΠϧܕ SHA-1ϋογϡ஋ εςʔδ਺ ϑΝΠϧ໊
    100644 ce013625030ba8dba906f756967f9e9ca394464a 0 README
    ϑΝΠϧܕͷ100644͸README͕௨ৗͷϑΝΠϧͰ͋Δ͜ͱΛࣔ͢
    
    εςʔδ਺͸Ϛʔδ͢Δͱ͖ͷڝ߹ͷঢ়ଶ

    (ڝ߹͕͋Δͱ̍Ҏ্ͷεςʔδ਺ 0ͩͱڝ߹ͳ͠)
    
    SHA-1ϋογϡ஋͸ϑΝΠϧ಺༰ʹج͍ͮͯܭࢉ͞ΕΔ160Ϗοτʹू໿͞ΕΔϥϯμϜͳ஋
    ಺༰͕ҰจࣈͰ΋ҧ͏ͱผͷ஋ʹͳΔ
    catͰΈͯ΋Α͘Θ͔Βͳ͍ͷͰ
    

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12. 12
    ΄Μͱʹҧ͏஋ʹͳΔͷʁ
    $echo 'hello!' > README
    $git add README
    $git ls-files -s
    READMEʹॻ͍ͨHelloΛHelle!ͱʂΛ଍ͯ͠ΈΑ͏
    
    ϑΝΠϧܕ SHA-1ϋογϡ஋ εςʔδ਺ ϑΝΠϧ໊
    100644 4effa19f4f75f846c3229b9dbdbad14eff362f32 0 README
    ͔ͨ͠ʹ಺༰͕ҰจࣈͰ΋ҧ͏ͱผͷ஋ʹͳΔ
    

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13. 13
    Ͳ͏ͯ͠ϋογϡ஋Λ࢖͏ͷʁ
    όʔδϣϯ؅ཧγεςϜ͸ಉҰϑΝΠϧͷ಺༰ͷมԽΛ௥੻͢Δ΋ͷ͔ͩΒ
    
    ϑΝΠϧ಺༰͕ಉ͡Ͱ͋Ε͹ͲΜͳ؀ڥͰ͋ͬͯ΋ಉ͡஋ʹͳΔ
    ͷ͕౎߹͕͍͍
    
    ϋογϡ஋͕ಉ͡=ϑΝΠϧ಺༰͕ಉ͡
    

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14. 14
    Ͳ͏΍ͬͯϋογϡ஋Λܭࢉ͢Δͷʁ
    SHA-1ϋογϡ஋ = ϔομʔ৘ใʴϑΝΠϧͷ಺༰
    ϔομʔ৘ใͱ͸
    ϔομʔ৘ใɿ֨ೲ͢ΔΦϒδΣΫτܕͱϑΝΠϧ಺༰ͷαΠζ
    ΦϒδΣΫτܕͱ͸
    ϑΝΠϧ͸blobɺϑΥϧμ͸treeͱ͍͏ΦϒδΣΫτܕʹͳΔ
    

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15. 15
    Ͳ͏΍ͬͯϋογϡ஋Λܭࢉ͢Δͷʁ
    ࠓճͷྫͩͱ
    (ΦϒδΣΫτܕ+σʔλαΠζ) Blob 7
    (ϑΝΠϧ಺༰)σʔλ Hello!
    $echo 'hello!' | git hash-object --stdin

    gitͷػೳͰϋογϡ஋Λग़ͯ͠ΈΔ
    ಉ͡஋ͩʂ
    ͜ͷ৘ใΛ࢖ͬͯSHA-1ϋογϡ஋Λग़ͤΔ
    

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16. 16
    ͜ͷϋογϡ஋ΛͲ͏࢖͍ͬͯΔͷʁ
    .git/objectsͷத਎ΛݟͯΈ·͠ΐ͏
    $find .git/objects

    ϋογϡ஋ͷ࠷ॳͷೋจࣈ͸αϒϑΥϧμ໊ɺ࢒Γͷ38จࣈ͸ϑΝΠϧ໊ͱ
    ͨ͠ύεʹʮblob 7 hello!ʯ͕อଘ͞Ε͍ͯΔ
    

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17. 17
    ͜ͷϋογϡ஋ΛͲ͏࢖͍ͬͯΔͷʁ
    ϋογϡ஋ͷύεΛݟͯΈ·͠ΐ͏
    $cd .git/objects

    $vi 4e/ffa19f4f75f846c3229b9dbdbad14eff362f32

    ͳʹ͜Εɾɾʁຊ౰ʹʮHello!ʯͳͷ?
    zlibͰѹॖ͞Εͯ͠·͏ͨΊจࣈ͸֬ೝͰ͖ͳ͍ͷͰͨ͠ɾɾɾ

    (zlib͸ɺσʔλͷѹॖ͓Αͼ৳ுΛߦ͏ͨΊͷϑϦʔͷϥΠϒϥϦ)
    

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18. 18
    ͜ͷϋογϡ஋ΛͲ͏࢖͍ͬͯΔͷʁ
    ѹॖͨ͠σʔλΛղಡͯ͠ΈΑ͏
    $git cat-file -t 4effa

    -t :λΠϓʢΦϒδΣΫτܕʣΛදࣔ
    ϋογϡ஋
    (ΦϒδΣΫτܕ+σʔλαΠζ) Blob 7
    (ϑΝΠϧ಺༰)σʔλ Hello!
    

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19. 19
    ͜ͷϋογϡ஋ΛͲ͏࢖͍ͬͯΔͷʁ
    ѹॖͨ͠σʔλΛղಡͯ͠ΈΑ͏
    $git cat-file -s 4effa

    -s :αΠζΛදࣔ
    ϋογϡ஋
    (ΦϒδΣΫτܕ+σʔλαΠζ) Blob 7
    (ϑΝΠϧ಺༰)σʔλ Hello!
    

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20. 20
    ͜ͷϋογϡ஋ΛͲ͏࢖͍ͬͯΔͷʁ
    ѹॖͨ͠σʔλΛղಡͯ͠ΈΑ͏
    $git cat-file -p 4effa

    -p :಺༰Λදࣔ
    ϋογϡ஋
    (ΦϒδΣΫτܕ+σʔλαΠζ) Blob 7
    (ϑΝΠϧ಺༰)σʔλ Hello!
    ͪΌΜͱσʔλ͕͍Δ
    

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21. 21
    Commitͯ͠ΈΑ͏
    

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22. 22
    ίϛοτ͢ΔͱͲ͏ͳΔͷʁ
    ίϛοτͯ͠ΈΑ͏
    $git commit -m "1st commit" 

    .git/objectsͷத਎ΛݟͯΈ·͠ΐ͏

    (ݕࡧର৅ΛϑΝΠϧͷΈʹݶఆͯ͠ݕࡧ͢ΔΦϓγϣϯΛ෇͚ͨfindίϚϯυ)
    $find .git/objects -type f

    ←hello
    ←hello!
    ←ίϛοτͨ͠Β

    ૿͑ͯΔ?!
    

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23. 23
    ૿͑ͨ̎ͭͷϋογϡ஋͸ͳΜͩΖ͏
    ίϛοτ͞ΕͨΦϒδΣΫτͷϋογϡͷϦετΛදࣔ͢ΔίϚϯυ
    $git rev-list --all --objects --format=oneline

    ←hello!ʹߋ৽ͨ͠ϋογϡ஋
    ←ίϛοτͨ͠Β૿͑ͨϋογϡ஋
    

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24. 24
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 34e600; git cat-file -s 34e600; git cat-file -p 34e600;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 34(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    treeΦϒδΣΫτ:34e600920700d3d2d96ff92e3c057a8d24b1f3ed
    

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25. 25
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 34e600; git cat-file -s 34e600; git cat-file -p 34e600;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 34(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    ↑Hello!ɹʹมߋͨ͠ίϛοτͩ
    treeΦϒδΣΫτ:34e600920700d3d2d96ff92e3c057a8d24b1f3ed
    

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26. 26
    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 34(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    ̋TreeΦϒδΣΫτ͸ίϛοτ࣌఺ͷΠϯσοΫε৘ใ͔Β࡞ΒΕΔ
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    ·ͱΊ
    (ΦϒδΣΫτܕ+σʔλαΠζ) Blob 7
    (ϑΝΠϧ಺༰)σʔλ Hello!
    ̋TreeΦϒδΣΫτ͸࠷ޙʹaddͨ͠ϋογϡ஋ʹؔ࿈෇͚ΒΕ͍ͯΔ
    ͜ͷσʔλ͔Βϋογϡ஋͕࡞ΒΕ͍ͯΔ
    treeΦϒδΣΫτ:34e600920700d3d2d96ff92e3c057a8d24b1f3ed
    blobΦϒδΣΫτ:4effa19f4f75f846c3229b9dbdbad14eff362f32
    

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27. 27
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(commitΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 57c0a; git cat-file -s 57c0a; git cat-file -p 57c0a;
    (ΦϒδΣΫτܕ+σʔλαΠζ) commit(ΦϒδΣΫτ) 195(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    TREE AUTHOR COMMITTER
    34e600920700d3d2d96ff92e3c057a8d24b1f3ed Marina Nakagawa Marina Nakagawa
    commitΦϒδΣΫτ:57c0a4b5d3002202a7b55be6eb3523b992527d09
    

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28. 28
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(commitΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 57c0a; git cat-file -s 57c0a; git cat-file -p 57c0a;
    (ΦϒδΣΫτܕ+σʔλαΠζ) commit(ΦϒδΣΫτ) 195(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    TREE AUTHOR COMMITTER
    34e600920700d3d2d96ff92e3c057a8d24b1f3ed Marina Nakagawa Marina Nakagawa
    ↑TreeΦϒδΣΫτͰ͖ͨϋογϡ஋ͩ
    commitΦϒδΣΫτ:57c0a4b5d3002202a7b55be6eb3523b992527d09
    CommitΦϒδΣΫτ͸͍ͭ୭͕ԿͷͨΊʹίϛοτͨ͠ͷ͔͕Θ͔Δ
    

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29. 29
    ίϛοτΛ͢ΔͱTreeΦϒδΣΫτͱcommitΦϒδΣΫτ͕࡞੒͞ΕΔ
    ίϛοτ͢ΔͱͲ͏ͳΔͷʁ
    (ΦϒδΣΫτܕ+σʔλαΠζ) commit(ΦϒδΣΫτ) 195(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    TREE AUTHOR COMMITTER
    34e600920700d3d2d96ff92e3c057a8d24b1f3ed Marina Nakagawa Marina Nakagawa
    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 34(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    commitΦϒδΣΫτ:57c0a4b5d3002202a7b55be6eb3523b992527d09
    treeΦϒδΣΫτ:34e600920700d3d2d96ff92e3c057a8d24b1f3ed
    (ΦϒδΣΫτܕ+σʔλαΠζ) Blob 7
    (ϑΝΠϧ಺༰)σʔλ Hello!
    blobΦϒδΣΫτ:4effa19f4f75f846c3229b9dbdbad14eff362f32
    

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30. 30
    ΋͏Ұ౓Commitͯ͠ΈΑ͏
    

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31. 31
    ผϑΝΠϧΛͭͬͯ͘ίϛοτ͢ΔͱͲ͏ͳΔͷʁ
    $mkdir test
    $cd test
    $echo 'Hello world' > sample.md
    $git add sample.md
    $git commit -m "2nd commit”
    testϑΥϧμΛ࡞ͬͯ Hello worldͱॻ͔Εͨsample.mdϑΝΠϧΛͭ͘Δ
    

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32. 32
    ίϛοτ͞ΕͨΦϒδΣΫτͷϋογϡͷϦετΛදࣔ͢ΔίϚϯυ
    $git rev-list --all --objects --format=oneline

    ผϑΝΠϧΛͭͬͯ͘ίϛοτ͢ΔͱͲ͏ͳΔͷʁ
    ←TreeΦϒδΣΫτ
    ←commitΦϒδΣΫτ
    

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33. 33
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t e3da65; git cat-file -s e3da64; git cat-file -p e3da64;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 65(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    40000 tree(ϑΥϧμͷҙ) 3b903ecdee168aad30b478201b8ff9d9b20c6119 test
    treeΦϒδΣΫτ:e3da64ffcb70336e1313bad123247c9691846bac
    ←TreeΦϒδΣΫτ
    

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34. 34
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t e3da65; git cat-file -s e3da64; git cat-file -p e3da64;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 65(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    40000 tree(ϑΥϧμͷҙ) 3b903ecdee168aad30b478201b8ff9d9b20c6119 test
    treeΦϒδΣΫτ:e3da64ffcb70336e1313bad123247c9691846bac
    ←TreeΦϒδΣΫτ
    ͜ͷTreeΦϒδΣΫτͰ͸̎ͭͷSHA-1ϋογϡ஋Λอ͍࣋ͯ͠Δ
    

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35. 35
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t e3da65; git cat-file -s e3da64; git cat-file -p e3da64;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 65(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    40000 tree(ϑΥϧμͷҙ) 3b903ecdee168aad30b478201b8ff9d9b20c6119 test
    treeΦϒδΣΫτ:e3da64ffcb70336e1313bad123247c9691846bac
    ←TreeΦϒδΣΫτ
    ࣍͸͜ΕΛ͠Β΂ͯΈ·͢
    

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36. 36
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 65(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    40000 tree(ϑΥϧμͷҙ) 3b903ecdee168aad30b478201b8ff9d9b20c6119 test
    treeΦϒδΣΫτ:e3da64ffcb70336e1313bad123247c9691846bac
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 3b903; git cat-file -s 3b903; git cat-file -p 3b903;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 37(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 802992c4220de19a90767f3000a79a31b98d0df7 sample.md
    treeΦϒδΣΫτ:3b903ecdee168aad30b478201b8ff9d9b20c6119
    

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37. 37
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(treeΦϒδΣΫτ)
    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 65(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 4effa19f4f75f846c3229b9dbdbad14eff362f32 README
    40000 tree(ϑΥϧμͷҙ) 3b903ecdee168aad30b478201b8ff9d9b20c6119 test
    treeΦϒδΣΫτ:e3da64ffcb70336e1313bad123247c9691846bac
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 3b903; git cat-file -s 3b903; git cat-file -p 3b903;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 37(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 802992c4220de19a90767f3000a79a31b98d0df7 sample.md
    treeΦϒδΣΫτ:3b903ecdee168aad30b478201b8ff9d9b20c6119
    ࣍͸͜ΕΛ͠Β΂ͯΈ·͢
    

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38. 38
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(blobΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 80299; git cat-file -s 80299; git cat-file -p 80299;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 12(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ Hello world
    blobΦϒδΣΫτ:802992c4220de19a90767f3000a79a31b98d0df7
    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 37(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 802992c4220de19a90767f3000a79a31b98d0df7 sample.md
    treeΦϒδΣΫτ:3b903ecdee168aad30b478201b8ff9d9b20c6119
    

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39. 39
    ૿͑ͨϋογϡ஋ͷ಺ͷ̍ͭΛݟΔ(blobΦϒδΣΫτ)
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t 80299; git cat-file -s 80299; git cat-file -p 80299;

    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 12(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ Hello world
    blobΦϒδΣΫτ:802992c4220de19a90767f3000a79a31b98d0df7
    (ΦϒδΣΫτܕ+σʔλαΠζ) treeΦϒδΣΫτ 37(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    ϑΝΠϧܕ ΦϒδΣΫτܕ SHA-1ϋογϡ஋ ϑΝΠϧɾϑΥϧμ໊
    100644 blob(ϑΝΠϧͷҙ) 802992c4220de19a90767f3000a79a31b98d0df7 sample.md
    treeΦϒδΣΫτ:3b903ecdee168aad30b478201b8ff9d9b20c6119
    ಺༰Λมߋͨ͠σʔλ͕Ͱ͖ͯͨ
    

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40. 40
    treeΦϒδΣΫτͱblobΦϒδΣΫτͷؔ܎ੑΛ·ͱΊΔͱ
    blobΦϒδΣΫτ:4effa19f4f75f846c3229b9dbdbad14eff362f32
    1st commit
    

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41. 41
    treeΦϒδΣΫτͱblobΦϒδΣΫτͷؔ܎ੑΛ·ͱΊΔͱ
    blobΦϒδΣΫτ:4effa19f4f75f846c3229b9dbdbad14eff362f32
    Hello!ͱ͍͏มߋͳͷͶʂ
    1st commitͷঢ়ଶΛ෮ݩͰ͖Δ
    1st commit
    

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42. 42
    treeΦϒδΣΫτͱblobΦϒδΣΫτͷؔ܎ੑΛ·ͱΊΔͱ
    blobΦϒδΣΫτ:4effa19f4f75f846c3229b9dbdbad14eff362f32
    2st commitͷঢ়ଶΛ෮ݩͰ͖Δ
    2nd commit
    

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43. 43
    TreeΦϒδΣΫτ͑͞Θ͔Ε͹
    ຤୺ͷϑΝΠϧ·ͰͨͲΓண͚Δ
    

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44. 44
    Tree͸Θ͔͚ͬͨͲ
    Commit͸Կͷҙຯ͕͋Δͷʁ
    

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45. 45
    ίϛοτ͞ΕͨΦϒδΣΫτͷϋογϡͷϦετΛදࣔ͢ΔίϚϯυ
    $git rev-list --all --objects --format=oneline

    ←commitΦϒδΣΫτ
    ೋͭ໨ͷίϛοτΦϒδΣΫτΛݟͯΈΑ͏
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t e3da65; git cat-file -s e3da64; git cat-file -p e3da64;

    

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46. 46
    ೋͭ໨ͷίϛοτΦϒδΣΫτΛݟͯΈΑ͏
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t cff23; git cat-file -s cff23; git cat-file -p cff23;
    (ΦϒδΣΫτܕ+σʔλαΠζ) commit(ΦϒδΣΫτ) 243(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    TREE PARENT AUTHOR COMMITTER
    e3da64ffcb70336e1313bad123247c9691846bac 57c0a4b5d3002202a7b55be6eb3523b992527d09
    Marina
    Nakagawa
    Marina
    Nakagawa
    commitΦϒδΣΫτ:cff23168b95204aa210c34f95394cafc00db847b
    

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47. 47
    ೋͭ໨ͷίϛοτΦϒδΣΫτΛݟͯΈΑ͏
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t cff23; git cat-file -s cff23; git cat-file -p cff23;
    (ΦϒδΣΫτܕ+σʔλαΠζ) commit(ΦϒδΣΫτ) 243(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    TREE PARENT AUTHOR COMMITTER
    e3da64ffcb70336e1313bad123247c9691846bac 57c0a4b5d3002202a7b55be6eb3523b992527d09
    Marina
    Nakagawa
    Marina
    Nakagawa
    commitΦϒδΣΫτ:cff23168b95204aa210c34f95394cafc00db847b
    ←͋ΕʁParent͕͍Δ
    

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48. 48
    ೋͭ໨ͷίϛοτΦϒδΣΫτΛݟͯΈΑ͏
    தΛղಡͯ͠ΈΑ͏
    $git cat-file -t cff23; git cat-file -s cff23; git cat-file -p cff23;
    (ΦϒδΣΫτܕ+σʔλαΠζ) commit(ΦϒδΣΫτ) 243(σʔλαΠζ)
    (ϑΝΠϧ಺༰)σʔλ
    TREE PARENT AUTHOR COMMITTER
    e3da64ffcb70336e1313bad123247c9691846bac 57c0a4b5d3002202a7b55be6eb3523b992527d09
    Marina
    Nakagawa
    Marina
    Nakagawa
    commitΦϒδΣΫτ:cff23168b95204aa210c34f95394cafc00db847b
    ←̍ͭલͷίϛοτΛࣔ͢
    

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49. 49
    CommitΦϒδΣΫτͱTreeΦϒδΣΫτΛ·ͱΊΔͱ
    2nd commit
    1st commit
    ࠷৽ͷίϛοτ͑͞Θ͔Ε͹࠷ॳͷίϛοτ·Ͱશͯͷྺ࢙Λ௥͑Δ
    

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50. 50
    CommitΦϒδΣΫτͱTreeΦϒδΣΫτΛ·ͱΊΔͱ
    2nd commit
    1st commit
    ͦΕͧΕͷίϛοτ͸TreeΦϒδΣΫτͷ৘ใΛ͍࣋ͬͯΔͨΊ
    ຤୺ͷϑΝΠϧ·ͰͨͲΓண͚Δ
    

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51. 51
    Commitͱ͸
    ̋̍ͭલͷίϛοτͱϓϩδΣΫτϧʔτͷtreeΦϒδΣΫτΛ஌ͬͯΔ
    ̋authorɾcommitterɾίϛοτϝοηʔδͷ৘ใ͕෇Ճ͞Εͨ΋ͷ
    

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52. 52
    Gitͷཪଆࢀߟࢿྉ
    ΄΅͜ΕΛৄࡉʹௐ΂ͨ΋ͷͰ͢
    

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