grantpt(3)

1GRANTPT(3)                 Linux Programmer's Manual                GRANTPT(3)
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NAME

6       grantpt - grant access to the slave pseudo-terminal
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SYNOPSIS

9       #define _XOPEN_SOURCE
10       #include <stdlib.h>
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12       int grantpt(int fd);
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DESCRIPTION

15       The  grantpt() function changes the mode and owner of the slave pseudo-
16       terminal device (pty) corresponding to the master pty  referred  to  by
17       fd.   The  user  ID  of the slave is set to the real UID of the calling
18       process.  The group ID is set to an unspecified value (e.g. tty).   The
19       mode of the slave is set to 0620 (crw--w----).
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21       The  behavior  of  grantpt()  is  unspecified  if  a  signal handler is
22       installed to catch SIGCHLD signals.
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RETURN VALUE

25       When successful, grantpt() returns 0. Otherwise, it returns -1 and sets
26       errno appropriately.
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ERRORS

29       EACCES The corresponding slave pty could not be accessed.
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31       EBADF  The fd argument is not a valid open file descriptor.
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33       EINVAL The fd argument is valid but not associated with a master pty.
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CONFORMING TO

36       POSIX.1-2001
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NOTES

39       This  is  part  of  the  Unix98  pty support, see pts(4).  Many systems
40       implement  this  function  via  a  set-user-ID  helper  binary   called
41       "pt_chown". With Linux devpts no such helper binary is required.
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