Perl で作る tiny shell

Perl で極限に機能を削った shell の作り方を紹介します

1. 1FSM
   Ͱ࡞Δ
 UJOZ
   TIFMM )PLLBJEPQN
   
2. !DPEFIFY !$PEF)FY w .FSDBSJ
   *OD
   w %FWFMPQJOH
   NJDSPTFSWJDFT
   w 0LJOBXBQN
   w *
   MJLF
   1FSM94(P
   w IUUQTDPEFIFYIBUFCMPKQ
3. γΣϧͬͯ஌ͬͯ·͔͢
5. /P
6. $ pwd

7. $ pwd
 /Users/codehex
8. #BTI
   ;TI
   pTI
9. γΣϧʹ͸
 ༷ʑͳػೳ͕͋Γ·͢
10. ྫ͑͹
11. ύΠϓ
12. $ pwd | cat -n

13. $ pwd | cat -n
 1 /Users/codehex
14. Ξϯυ
15. $ pwd && echo hello

16. $ pwd && echo hello
 /Users/codehex
 hello
17. ͜ΕΒͷ
 ࣮૷Λ஌͍ͬͯ·͔͢ʁ
18. ࠓ೔࿩͢಺༰
19. ࠓ೔࿩͢಺༰ w ࠷௿ݶͷγΣϧͷఆٛ
    w ߏจղੳ
    w ίϚϯυͷ࣮ߦ
20. ࠓ೔࿩͢಺༰ w ࠷௿ݶͷγΣϧͷఆٛ
    w ߏจղੳ
    w ίϚϯυͷ࣮ߦ
21. ࠷௿ݶͷγΣϧͷఆٛ UJOZ
    TIFMM
    ͷಈ࡞Λఆٛ͢Δ
22. lUJOZ
    TIFMMz
    NFBOT
 ΊͬͪΌখ͍͞γΣϧ
23. Ͳ͏͍͏ಈ࡞Λ͢Δ͔
24. Ͳ͏͍͏ಈ࡞Λ͢Δ͔ w ୯ҰίϚϯυͷ࣮ߦ
    
    $ ls
    
    w ύΠϓͷ࣮ߦ
    
    $ ls | cat
    w ΞϯυʹΑΔෳ਺࣮ߦ
    
    $ ls && cat
    w αϒγΣϧ΍όοΫάϥϯυ࣮ߦ͸ࠓճؚΊ·ͤΜ
25. ࠓ೔࿩͢಺༰ w ࠷௿ݶͷγΣϧͷఆٛ
    w ߏจղੳ
    w ίϚϯυͷ࣮ߦ
26. ߏจղੳ ެจఆٛͱߏจղੳثͷ࡞੒
27. $ cat | cat -n && ls
28. $ cat | cat -n && ls
29. $ cat | cat -n && ls
30. $ cat | cat -n && ls
31. $ cat | cat -n && ls
32. $ cat | cat -n && ls ࠨ͔Βӈʹղऍ͠·͢
33. ߏจͷఆٛ
34. ӈʹ࿈͍݁ͯ͘͠Α͏ʹ
 ఆٛ෇͚Λߦ͏
35. ߏจఆٛ • CMD: [a-zA-Z_-][0-9a-zA-Z_-]* <ARG> • ARG: [0-9a-zA-Z_-]* <ARG> | [0-9a-zA-Z_-]* • SHLL: <PIPE> '&&' <AND> | <PIPE> • PIPE: <CMD> '|' <PIPE> | <CMD> • AND: <SHLL> '&&' <AND> | <SHLL>
36. ߏจղੳثͷ࡞੒
37. ߏจղੳثʹඞཁͳཁૉ
38. ߏจղੳثʹඞཁͳཁૉ w จࣈྻͷεΩϟφʔ
    w ಡΈࠐΈҐஔ΍ಡΈऔͬͨจࣈྻΛอ࣋͢Δ
    w จࣈྻͷϚονϯά
    w εΩϟφʔͰಘͨจࣈྻ͕ߏจఆٛʹϚονͨ͠ ͔Ͳ͏͔൑ผ͢Δ
    w Ϛονͨ͠จࣈྻʹҙຯΛ΋ͨͤΔ τʔΫϯԽ
    w ߏจ໦ͷੜ੒
39. 1FSM
    Ͱ͸ʁ
40. ਖ਼نදݱ
    
41. IUUQTQFSMEPDQFSMPSHQFSMPQIUNMD(@BTTFSUJPO@ l"
    VTFGVM
    JEJPN
    GPS
    AlexA
    MJLF
    
 TDBOOFST
    JT
    A/\G…/gcA
    ʜz
42. /\G…/gc
43. /\G…/gc w A/cA
    NPEJpFS
    Ͱ͸ݱࡏϚον͍ͯ͠ΔҐஔΛ
 อ࣋͢Δ͜ͱ͕Ͱ͖Δɻ
    • pos()
    ͰҐஔΛऔΓग़͢͜ͱ͕Մೳ
    • \G
    Ͱલճ
    Am//gA
    ͰϚονͨ͠ҐஔΛอ࣋͢Δ͜ͱ ͕Մೳ
44. εΩϟφʔͱϚονϯάͷ
 ໾ׂΛ΋ͭ͜ͱ͕Ͱ͖Δ ?P? W
45. ͜͜Ͱྑ͍৘ใ
46. ΊͬͪΌࢀߟʹͳΔϖʔδ w IUUQTHJUIVCDPNLBSVQBOFSVSBQ +40/CMPCNBTUFSMJC+40/1BSTFSQN
    w IUUQTHJUIVCDPNLBSVQBOFSVSB50.- 1BSTFSCMPCNBTUFSMJC50.-1BSTFSQN
47. ࣮૷༷ࢠ
48. ߏจఆٛ • CMD: [a-zA-Z_-][0-9a-zA-Z_-]* <ARG> • ARG: [0-9a-zA-Z_-]* <ARG> | [0-9a-zA-Z_-]* • SHLL: <PIPE> '&&' <AND> | <PIPE> • PIPE: <CMD> '|' <PIPE> | <CMD> • AND: <SHLL> '&&' <AND> | <SHLL>
49. $.%
50. ߏจఆٛ • CMD: [a-zA-Z_-][0-9a-zA-Z_-]* <ARG> • ARG: [0-9a-zA-Z_-]* <ARG> | [0-9a-zA-Z_-]* • SHLL: <PIPE> '&&' <AND> | <PIPE> • PIPE: <CMD> '|' <PIPE> | <CMD> • AND: <SHLL> '&&' <AND> | <SHLL>
51. 4)--
52. ߏจఆٛ • CMD: [a-zA-Z_-][0-9a-zA-Z_-]* <ARG> • ARG: [0-9a-zA-Z_-]* <ARG> | [0-9a-zA-Z_-]* • SHLL: <PIPE> '&&' <AND> | <PIPE> • PIPE: <CMD> '|' <PIPE> | <CMD> • AND: <SHLL> '&&' <AND> | <SHLL>
53. 1*1&
54. ߏจఆٛ • CMD: [a-zA-Z_-][0-9a-zA-Z_-]* <ARG> • ARG: [0-9a-zA-Z_-]* <ARG> | [0-9a-zA-Z_-]* • SHLL: <PIPE> '&&' <AND> | <PIPE> • PIPE: <CMD> '|' <PIPE> | <CMD> • AND: <SHLL> '&&' <AND> | <SHLL>
55. "/%
56. ໦Λ
    QSJOU
    ༷ͨ͠ࢠ $ cat | cat -n && ls
57. "/% 1*1& DBU DBU MT $ cat | cat -n && ls
58. ͪͳΈʹ
59. $ cat | cat -n && ls
60. $ cat | cat -n && ls ࠨ͔Βӈʹղऍ͠·͢
61. ͳͷͰ
 ໦ΛḷΔͱ͖͸
62. "/% 1*1& DBU DBU MT $ cat | cat -n && ls ᶃ
63. "/% 1*1& DBU DBU MT $ cat | cat -n && ls ᶃ ᶄ ᶅ
64. "/% 1*1& DBU DBU MT $ cat | cat -n && ls ᶃ ᶄ ᶅ ᶆ ᶇ
65. ͜ΕΛجʹ
 ࣮ߦ͢ΔػೳΛ࡞੒͠·͢
66. ࠓ೔࿩͢಺༰ w ࠷௿ݶͷγΣϧͷఆٛ
    w ߏจղੳ
    w ίϚϯυͷ࣮ߦ
67. ίϚϯυͷ࣮ߦ ߏจ໦Λجʹ࣮ߦ͢Δ
68. ࣮૷ͷલʹ
69. ඪ४ετϦʔϜʹ͍ͭͯ
70. w 45%*/
    4UBOEBSE
    *OQVU
    ඪ४ೖྗ
    w 45%065
    4UBOEBSE
    0VUQVU
    ඪ४ग़ྗ
    w 45%&33
    4UBOEBSE
    &SSPS
    ඪ४Τϥʔग़ྗ ඪ४ετϦʔϜ
71. ͜ΕΒ͸࣮࣭
 ϑΝΠϧͱͯ͠ѻΘΕ·͢
72. ୯ҰίϚϯυͷ
 ετϦʔϜͷϑϩʔ
73. $ cat
74. $ cat cat 45%*/
75. $ cat cat 45%*/ 45%065 45%&33
76. $ cat GPSL
    Λ࢖͏ͱ
    TI
    Λհ͞ͳ͍Ͱ࣮ߦՄೳ
77. ύΠϓͷϑϩʔ
78. $ fortune | cowsay
79. $ fortune | cowsay 45%*/ PS
    /PU ᶃ
80. $ fortune | cowsay 45%*/ PS
    /PU 45%065 ᶃ ᶄ
81. $ fortune | cowsay 45%*/ PS
    /PU 45%065 45%*/ ᶃ ᶄ ᶅ
82. $ fortune | cowsay 45%*/ PS
    /PU 45%065 45%*/ 45%065 ᶃ ᶄ ᶅ ᶆ
83. ͜ΕΒͷίϚϯυ͸
 ผϓϩηεͰಈ͍͍ͯ·͢
84. $ ps a | cat 1*%
85. ύΠϓͷ࣮૷
86. pipe my ($r, $w);
87. w $r
    ͕
    3FBEFS
    $w
    ͕
    8SJUFS
    w 8SJUFS
    ʹσʔλ͕ॻ͖ࠐ·Εͨͱ͖
 3FBEFS
    ͰͦͷσʔλΛಡΈऔΔ͜ͱ͕Մೳ pipe my ($r, $w);
88. ֤ϓϩηεؒͷετϦʔϜΛ
 pipe()
    Ͱܨ͛Δ͜ͱͰ࣮૷Մೳ
89. ͦͷ࣌ͷϑϩʔ
90. $ fortune | cowsay 45%*/ PS
    /PU 45%065 ᶃ ᶄ
91. $ fortune | cowsay 45%*/ PS
    /PU 45%065 ᶃ ᶄ ᶅ ᶆ 8SJUFS 3FBEFS
92. $ fortune | cowsay 45%*/ PS
    /PU 45%065 45%*/ 45%065 ᶃ ᶄ ᶅ ᶆ 8SJUFS 3FBEFS ᶇ ᶈ ᶉ
93. ͳͷͰ࣮࣭
 ͜ͷΑ͏ʹߟ͑ΒΕΔ
94. $ fortune | cowsay 45%*/ PS
    /PU 8SJUFS 3FBEFS 45%065 ᶃ ᶄ ᶅ ᶆ
96. w ίϚϯυ
    OPEF
    Ͱ͔ͭ਌
    OPEF
    ͕ύΠϓͰ͸ͳ͍
 ৔߹͸ଈίϚϯυΛ࣮ߦ
    w ͦΕҎ֎͸ίϚϯυΛอ࣋͢Δ
    w ύΠϓ
    OPEF
    ͔ͭ਌͕ύΠϓ
    OPEF
    Ͱ͸ͳ͍৔߹
 อ࣋͠ଓ͚ͨίϚϯυΛ࣮ߦ
97. Ξϯυͷϑϩʔ
98. $ echo hello && echo world
99. $ echo hello && echo world ᶃ
100. $ echo hello && echo world ᶃ ᶄ
101. w Ξϯυ
     OPEF
     ʹདྷΔ·Ͱʹࠨͷ
     OPEF
     Λ
 શ࣮ͯߦ͢Δ
     w ੒ޭͨ͠৔߹ӈͷ
     OPEF
     Λࠨͷ
     OPEF
     ͱಉ͡Α͏ ʹ࣮ߦ͢Δ
102. ͜Ε͚ͩͰ
 UJOZ
     TIFMM
     ͕׬੒͠·͢ʂ
103. ·ͱΊ
104. ·ͱΊ w ӈʹ࿈͍݁ͯ͘͠Α͏ʹߏจఆٛͨ͠
     w γΣϧͷύΠϓɺΞϯυػೳΛཧղͯ͠ɺղੳ࣌ʹ ࣮ߦ͢ΔػೳΛ࡞੒ͨ͠
105. ࣭໰Ͳ͏ͧ https://github.com/Code-Hex/p5-Shell-Tiny