1TCGETPGRP(3) Linux Programmer's Manual TCGETPGRP(3)
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6 tcgetpgrp, tcsetpgrp - get and set terminal foreground process group
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9 #include <unistd.h>
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11 pid_t tcgetpgrp(int fd);
12 int tcsetpgrp(int fd, pid_t pgrp);
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15 The function tcgetpgrp() returns the process group ID of the foreground
16 process group on the terminal associated to fd, which must be the con‐
17 trolling terminal of the calling process.
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19 The function tcsetpgrp() makes the process group with process group ID
20 pgrp the foreground process group on the terminal associated to fd,
21 which must be the controlling terminal of the calling process, and
22 still be associated with its session. Moreover, pgrp must be a
23 (nonempty) process group belonging to the same session as the calling
24 process.
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26 If tcsetpgrp() is called by a member of a background process group in
27 its session, and the calling process is not blocking or ignoring SIGT‐
28 TOU, a SIGTTOU signal is sent to all members of this background process
29 group.
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32 When fd refers to the controlling terminal of the calling process, the
33 function tcgetpgrp() will return the foreground process group ID of
34 that terminal if there is one, and some value larger than 1 that is not
35 presently a process group ID otherwise. When fd does not refer to the
36 controlling terminal of the calling process, -1 is returned, and errno
37 is set to indicate the error.
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39 When successful, tcsetpgrp() returns 0. Otherwise, it returns -1, and
40 errno is set to indicate the error.
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43 EBADF fd is not a valid file descriptor.
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45 EINVAL pgrp has an unsupported value.
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47 ENOTTY The calling process does not have a controlling terminal, or it
48 has one but it is not described by fd, or, for tcsetpgrp(), this
49 controlling terminal is no longer associated with the session of
50 the calling process.
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52 EPERM pgrp has a supported value, but is not the process group ID of a
53 process in the same session as the calling process.
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56 For an explanation of the terms used in this section, see at‐
57 tributes(7).
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59 ┌────────────────────────────────────────────┬───────────────┬─────────┐
60 │Interface │ Attribute │ Value │
61 ├────────────────────────────────────────────┼───────────────┼─────────┤
62 │tcgetpgrp(), tcsetpgrp() │ Thread safety │ MT-Safe │
63 └────────────────────────────────────────────┴───────────────┴─────────┘
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66 POSIX.1-2001, POSIX.1-2008.
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69 These functions are implemented via the TIOCGPGRP and TIOCSPGRP ioctls.
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71 History
72 The ioctls appeared in 4.2BSD. The functions are POSIX inventions.
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75 setpgid(2), setsid(2), credentials(7)
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78 This page is part of release 5.12 of the Linux man-pages project. A
79 description of the project, information about reporting bugs, and the
80 latest version of this page, can be found at
81 https://www.kernel.org/doc/man-pages/.
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85GNU 2021-03-22 TCGETPGRP(3)