projects / unix-history / blame
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1 | .\" Copyright (c) 1980, 1991, 1993 |
| 2 | .\" The Regents of the University of California. All rights reserved. | |
| 384b8076 | 3 | .\" |
| 931b8415 | 4 | .\" %sccs.include.redist.man% |
| 384b8076 | 5 | .\" |
| 653ba8b6 | 6 | .\" @(#)ioctl.2 8.2 (Berkeley) %G% |
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7 | .\" |
| 8 | .Dd | |
| 9 | .Dt IOCTL 2 | |
| 10 | .Os BSD 4 | |
| 11 | .Sh NAME | |
| 12 | .Nm ioctl | |
| 13 | .Nd control device | |
| 14 | .Sh SYNOPSIS | |
| 15 | .Fd #include <sys/ioctl.h> | |
| 16 | .Ft int | |
| 17 | .Fn ioctl "int d" "unsigned long request" "char *argp" | |
| 18 | .Sh DESCRIPTION | |
| 19 | The | |
| 20 | .Fn ioctl | |
| 21 | function manipulates the underlying device parameters of special files. | |
| 22 | In particular, many operating | |
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23 | characteristics of character special files (e.g. terminals) |
| 24 | may be controlled with | |
| 931b8415 | 25 | .Fn ioctl |
| 6234b5e5 | 26 | requests. |
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27 | The argument |
| 28 | .Fa d | |
| 29 | must be an open file descriptor. | |
| 30 | .Pp | |
| 6234b5e5 | 31 | An ioctl |
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32 | .Fa request |
| 33 | has encoded in it whether the argument is an | |
| 34 | .Dq in | |
| 35 | parameter | |
| 36 | or | |
| 37 | .Dq out | |
| 38 | parameter, and the size of the argument | |
| 39 | .Fa argp | |
| 40 | in bytes. | |
| 6234b5e5 | 41 | Macros and defines used in specifying an ioctl |
| 931b8415 | 42 | .Fa request |
| 6234b5e5 | 43 | are located in the file |
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44 | .Ao Pa sys/ioctl.h Ac . |
| 45 | .Sh RETURN VALUES | |
| 46 | If an error has occurred, a value of -1 is returned and | |
| 47 | .Va errno | |
| 6234b5e5 | 48 | is set to indicate the error. |
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49 | .Sh ERRORS |
| 50 | .Fn Ioctl | |
| 653ba8b6 | 51 | will fail if: |
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52 | .Bl -tag -width [ENOTTY] |
| 53 | .It Bq Er EBADF | |
| 54 | .Fa d | |
| 55 | is not a valid descriptor. | |
| 56 | .It Bq Er ENOTTY | |
| 57 | .Fa d | |
| 58 | is not associated with a character | |
| 6234b5e5 | 59 | special device. |
| 931b8415 | 60 | .It Bq Er ENOTTY |
| 6234b5e5 | 61 | The specified request does not apply to the kind |
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62 | of object that the descriptor |
| 63 | .Fa d | |
| 64 | references. | |
| 65 | .It Bq Er EINVAL | |
| 66 | .Fa Request | |
| 67 | or | |
| 68 | .Fa argp | |
| 69 | is not valid. | |
| 70 | .El | |
| 71 | .Sh SEE ALSO | |
| 72 | .Xr mt 1 , | |
| 73 | .Xr execve 2 , | |
| 74 | .Xr fcntl 2 , | |
| 75 | .Xr tty 4 , | |
| 76 | .Xr intro 4 | |
| 77 | .Sh HISTORY | |
| 78 | An | |
| 79 | .Nm | |
| 80 | function call appeared in Version 7 AT&T UNIX. |