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a/src/utils/closefrom.cpp |
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b/src/utils/closefrom.cpp |
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... |
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... |
| 26 |
*
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26 |
*
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| 27 |
* There are many reasons for closing file descriptors before
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27 |
* There are many reasons for closing file descriptors before
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| 28 |
* an exec (security, pipe control, the possibility that a bug will trigger
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28 |
* an exec (security, pipe control, the possibility that a bug will trigger
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| 29 |
* an unwanted write, etc.)
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29 |
* an unwanted write, etc.)
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| 30 |
*
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30 |
*
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| 31 |
* A process has currently no POSIX way to determine the list of open file
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31 |
* A process has currently no POSIX way to determine the set of open file
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| 32 |
* descriptors or at least the highest value. Closing all files (except a few),
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32 |
* descriptors or at least the highest value. Closing all files (except a few),
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| 33 |
* thus implies performing a close() system call on each entry up to the
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33 |
* thus implies performing a close() system call on each entry up to the
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| 34 |
* maximum, which can be both relatively difficult to determine, and quite
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34 |
* maximum, which can be both relatively difficult to determine, and quite
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| 35 |
* high (ie: several thousands), incurring a non-negligible cost.
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35 |
* high (ie: several thousands), incurring a non-negligible cost.
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| 36 |
*
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36 |
*
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... |
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... |
| 44 |
* getting-the-highest-allocated-file-descriptor
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44 |
* getting-the-highest-allocated-file-descriptor
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| 45 |
*
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45 |
*
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| 46 |
* System interfaces:
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46 |
* System interfaces:
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| 47 |
* FreeBSD:
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47 |
* FreeBSD:
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| 48 |
* - Has a closefrom() system call as of release 7.x around Sep 2009
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48 |
* - Has a closefrom() system call as of release 7.x around Sep 2009
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| 49 |
* - Has a /dev/fd, directory which lists the current process' open
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49 |
* - Has a /dev/fd, directory which shows the current process' open
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| 50 |
* descriptors. Only descriptors 0, 1, 2 are shown except if
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50 |
* descriptors. Only descriptors 0, 1, 2 are shown except if
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| 51 |
* fdescfs is mounted which it is not by default
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51 |
* fdescfs is mounted which it is not by default
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| 52 |
*
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52 |
*
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| 53 |
* Interface:
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53 |
* Interface:
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| 54 |
* int libclf_closefrom(fd)
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54 |
* int libclf_closefrom(fd)
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