unlockpt(3)

1unlockpt(3)                Library Functions Manual                unlockpt(3)
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NAME

6       unlockpt - unlock a pseudoterminal master/slave pair
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LIBRARY

9       Standard C library (libc, -lc)
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SYNOPSIS

12       #define _XOPEN_SOURCE
13       #include <stdlib.h>
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15       int unlockpt(int fd);
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       unlockpt():
20           Since glibc 2.24:
21               _XOPEN_SOURCE >= 500
22           glibc 2.23 and earlier:
23               _XOPEN_SOURCE
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DESCRIPTION

26       The  unlockpt() function unlocks the slave pseudoterminal device corre‐
27       sponding to the master pseudoterminal referred to by the file  descrip‐
28       tor fd.
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30       unlockpt()  should  be  called before opening the slave side of a pseu‐
31       doterminal.
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RETURN VALUE

34       When successful, unlockpt() returns 0.  Otherwise, it  returns  -1  and
35       sets errno to indicate the error.
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ERRORS

38       EBADF  The fd argument is not a file descriptor open for writing.
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40       EINVAL The fd argument is not associated with a master pseudoterminal.
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ATTRIBUTES

43       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
44       tributes(7).
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46       ┌────────────────────────────────────────────┬───────────────┬─────────┐
47       │Interface                                   │ Attribute     │ Value   │
48       ├────────────────────────────────────────────┼───────────────┼─────────┤
49       │unlockpt()                                  │ Thread safety │ MT-Safe │
50       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

53       POSIX.1-2008.
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HISTORY

56       glibc 2.1.  POSIX.1-2001.
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