Processus et démons sous Unix/Linux

Transcript

1. Des processus et démons
   sous Unix/Linux
   Jérémy Lecour — PastisRb et PLUG — avril 2014
   

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2. Jesse Storimer
   jstorimer.com
   

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3. Kernel et appels systèmes
   

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4. Kernel
   Matériel
   Logiciel
   

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5. processus
   Les processus
   

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6. ont un id
   Les processus
   processus
   

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7. ont un parent
   Les processus
   processus
   

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8. ont des ressources ouvertes
   Les processus
   processus
   

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9. ont des limites de ressources
   Les processus
   processus
   

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10. ont un environnement
    Les processus
    processus
    

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11. ont des arguments
    Les processus
    processus
    

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12. ont un nom
    Les processus
    processus
    

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13. ont des codes de retour
    Les processus
    processus
    

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14. peuvent fourcher
    Les processus
    processus
    

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15. peuvent virer Zombie
    Les processus
    processus
    

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16. recevoir des signaux
    Les processus
    processus
    

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17. processus
    Signal Value Action Comment
    -------------------------------------------------------------------------
    SIGHUP 1 Term Hangup detected on controlling terminal
    or death of controlling process
    SIGINT 2 Term Interrupt from keyboard
    SIGQUIT 3 Core Quit from keyboard
    SIGILL 4 Core Illegal Instruction
    SIGABRT 6 Core Abort signal from abort(3)
    SIGFPE 8 Core Floating point exception
    SIGKILL 9 Term Kill signal
    SIGSEGV 11 Core Invalid memory reference
    SIGPIPE 13 Term Broken pipe: write to pipe with no readers
    SIGALRM 14 Term Timer signal from alarm(2)
    SIGTERM 15 Term Termination signal
    SIGUSR1 30,10,16 Term User-defined signal 1
    SIGUSR2 31,12,17 Term User-defined signal 2
    SIGCHLD 20,17,18 Ign Child stopped or terminated
    SIGCONT 19,18,25 Cont Continue if stopped
    SIGSTOP 17,19,23 Stop Stop process
    SIGTSTP 18,20,24 Stop Stop typed at tty
    SIGTTIN 21,21,26 Stop tty input for background process
    SIGTTOU 22,22,27 Stop tty output for background process
    

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18. peuvent communiquer
    Les processus
    processus
    

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19. Qu’est-ce qu’un démon
    

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20. 1. exit if fork
    2. Process.setsid
    3. exit if fork
    4. Dir.chdir "/"
    5. STDIN.reopen "/dev/null"
    6. STDOUT.reopen "/dev/null", "a"
    7. STDERR.reopen "/dev/null", "a"
    

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21. 1. exit if fork
    2. Process.setsid
    3. exit if fork
    4. Dir.chdir "/"
    5. STDIN.reopen "/dev/null"
    6. STDOUT.reopen "/dev/null", "a"
    7. STDERR.reopen "/dev/null", "a"
    

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22. 1. exit if fork
    2. Process.setsid
    3. exit if fork
    4. Dir.chdir "/"
    5. STDIN.reopen "/dev/null"
    6. STDOUT.reopen "/dev/null", "a"
    7. STDERR.reopen "/dev/null", "a"
    

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23. 1. exit if fork
    2. Process.setsid
    3. exit if fork
    4. Dir.chdir "/"
    5. STDIN.reopen "/dev/null"
    6. STDOUT.reopen "/dev/null", "a"
    7. STDERR.reopen "/dev/null", "a"
    

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24. 1. exit if fork
    2. Process.setsid
    3. exit if fork
    4. Dir.chdir "/"
    5. STDIN.reopen "/dev/null"
    6. STDOUT.reopen "/dev/null", "a"
    7. STDERR.reopen "/dev/null", "a"
    

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25. 1. exit if fork
    2. Process.setsid
    3. exit if fork
    4. Dir.chdir "/"
    5. STDIN.reopen "/dev/null"
    6. STDOUT.reopen "/dev/null", "a"
    7. STDERR.reopen "/dev/null", "a"
    

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27. Merci
    

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28. jeremy.lecour@gmail.com
    @jlecour
    jeremy.wordpress.com
    github.com/jlecour
    

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