1Fcntl(3pm) Perl Programmers Reference Guide Fcntl(3pm)
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6 Fcntl - load the C Fcntl.h defines
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9 use Fcntl;
10 use Fcntl qw(:DEFAULT :flock);
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13 This module is just a translation of the C fcntl.h file. Unlike the
14 old mechanism of requiring a translated fcntl.ph file, this uses the
15 h2xs program (see the Perl source distribution) and your native C
16 compiler. This means that it has a far more likely chance of getting
17 the numbers right.
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20 Only "#define" symbols get translated; you must still correctly pack up
21 your own arguments to pass as args for locking functions, etc.
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24 By default your system's F_* and O_* constants (eg, F_DUPFD and
25 O_CREAT) and the FD_CLOEXEC constant are exported into your namespace.
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27 You can request that the flock() constants (LOCK_SH, LOCK_EX, LOCK_NB
28 and LOCK_UN) be provided by using the tag ":flock". See Exporter.
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30 You can request that the old constants (FAPPEND, FASYNC, FCREAT,
31 FDEFER, FEXCL, FNDELAY, FNONBLOCK, FSYNC, FTRUNC) be provided for
32 compatibility reasons by using the tag ":Fcompat". For new
33 applications the newer versions of these constants are suggested
34 (O_APPEND, O_ASYNC, O_CREAT, O_DEFER, O_EXCL, O_NDELAY, O_NONBLOCK,
35 O_SYNC, O_TRUNC).
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37 For ease of use also the SEEK_* constants (for seek() and sysseek(),
38 e.g. SEEK_END) and the S_I* constants (for chmod() and stat()) are
39 available for import. They can be imported either separately or using
40 the tags ":seek" and ":mode".
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42 Please refer to your native fcntl(2), open(2), fseek(3), lseek(2)
43 (equal to Perl's seek() and sysseek(), respectively), and chmod(2)
44 documentation to see what constants are implemented in your system.
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46 See perlopentut to learn about the uses of the O_* constants with
47 sysopen().
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49 See "seek" in perlfunc and "sysseek" in perlfunc about the SEEK_*
50 constants.
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52 See "stat" in perlfunc about the S_I* constants.
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56perl v5.32.1 2021-03-31 Fcntl(3pm)