projects / apple / xnu.git / blame
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| 9bccf70c A |
1 | .\" $NetBSD: getlogin.2,v 1.4 1995/02/27 12:33:03 cgd Exp $ |
| 2 | .\" | |
| 3 | .\" Copyright (c) 1989, 1991, 1993 | |
| 4 | .\" The Regents of the University of California. All rights reserved. | |
| 5 | .\" | |
| 6 | .\" Redistribution and use in source and binary forms, with or without | |
| 7 | .\" modification, are permitted provided that the following conditions | |
| 8 | .\" are met: | |
| 9 | .\" 1. Redistributions of source code must retain the above copyright | |
| 10 | .\" notice, this list of conditions and the following disclaimer. | |
| 11 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
| 12 | .\" notice, this list of conditions and the following disclaimer in the | |
| 13 | .\" documentation and/or other materials provided with the distribution. | |
| 14 | .\" 3. All advertising materials mentioning features or use of this software | |
| 15 | .\" must display the following acknowledgement: | |
| 16 | .\" This product includes software developed by the University of | |
| 17 | .\" California, Berkeley and its contributors. | |
| 18 | .\" 4. Neither the name of the University nor the names of its contributors | |
| 19 | .\" may be used to endorse or promote products derived from this software | |
| 20 | .\" without specific prior written permission. | |
| 21 | .\" | |
| 22 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 23 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 24 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 25 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 26 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 27 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 28 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 29 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 30 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 31 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 32 | .\" SUCH DAMAGE. | |
| 33 | .\" | |
| 34 | .\" @(#)getlogin.2 8.1 (Berkeley) 6/9/93 | |
| 35 | .\" | |
| 36 | .Dd June 9, 1993 | |
| 37 | .Dt GETLOGIN 2 | |
| 38 | .Os BSD 4.2 | |
| 39 | .Sh NAME | |
| 40 | .Nm getlogin , | |
| 41 | .Nm setlogin | |
| 42 | .Nd get/set login name | |
| 43 | .Sh SYNOPSIS | |
| 44 | .Fd #include <unistd.h> | |
| 45 | .Ft char * | |
| 2d21ac55 A |
46 | .Fo getlogin |
| 47 | .Fa void | |
| 48 | .Fc | |
| 9bccf70c | 49 | .Ft int |
| 2d21ac55 A |
50 | .Fo setlogin |
| 51 | .Fa "const char *name" | |
| 52 | .Fc | |
| 9bccf70c A |
53 | .Sh DESCRIPTION |
| 54 | The | |
| 55 | .Fn getlogin | |
| 56 | routine | |
| 57 | returns the login name of the user associated with the current session, | |
| 58 | as previously set by | |
| 59 | .Fn setlogin . | |
| 60 | The name is normally associated with a login shell | |
| 61 | at the time a session is created, | |
| 62 | and is inherited by all processes descended from the login shell. | |
| 63 | (This is true even if some of those processes assume another user ID, | |
| 64 | for example when | |
| 65 | .Xr su 1 | |
| 66 | is used.) | |
| 67 | .Pp | |
| 39037602 | 68 | .Fn setlogin |
| 9bccf70c A |
69 | sets the login name of the user associated with the current session to |
| 70 | .Fa name . | |
| 71 | This call is restricted to the super-user, and | |
| 72 | is normally used only when a new session is being created on behalf | |
| 73 | of the named user | |
| 74 | (for example, at login time, or when a remote shell is invoked). | |
| 75 | .Sh RETURN VALUES | |
| 76 | If a call to | |
| 77 | .Fn getlogin | |
| 78 | succeeds, it returns a pointer to a null-terminated string in a static buffer. | |
| 79 | If the name has not been set, it returns | |
| 80 | .Dv NULL . | |
| 81 | If a call to | |
| 82 | .Fn setlogin | |
| 83 | succeeds, a value of 0 is returned. If | |
| 84 | .Fn setlogin | |
| 85 | fails, a value of -1 is returned and an error code is | |
| 86 | placed in the global location | |
| 87 | .Va errno . | |
| 88 | .Sh ERRORS | |
| 89 | The following errors may be returned by these calls: | |
| 90 | .Bl -tag -width Er | |
| 91 | .It Bq Er EFAULT | |
| 92 | The | |
| 93 | .Fa name | |
| 94 | parameter gave an | |
| 95 | invalid address. | |
| 96 | .It Bq Er EINVAL | |
| 97 | The | |
| 98 | .Fa name | |
| 99 | parameter | |
| 100 | pointed to a string that was too long. | |
| 101 | Login names are limited to | |
| 102 | .Dv MAXLOGNAME | |
| 103 | (from | |
| 104 | .Ao Pa sys/param.h Ac ) | |
| 105 | characters, currently 12. | |
| 106 | .It Bq Er EPERM | |
| 107 | The caller tried to set the login name and was not the super-user. | |
| 108 | .El | |
| 109 | .Sh SEE ALSO | |
| 110 | .Xr setsid 2 | |
| 111 | .Sh BUGS | |
| 112 | Login names are limited in length by | |
| 113 | .Fn setlogin . | |
| 114 | However, lower limits are placed on login names elsewhere in the system | |
| 115 | .Pf ( Dv UT_NAMESIZE | |
| 116 | in | |
| 117 | .Ao Pa utmp.h Ac ) . | |
| 118 | .Pp | |
| 119 | In earlier versions of the system, | |
| 120 | .Fn getlogin | |
| 121 | failed unless the process was associated with a login terminal. | |
| 122 | The current implementation (using | |
| 123 | .Fn setlogin ) | |
| 124 | allows getlogin to succeed even when the process has no controlling terminal. | |
| 125 | In earlier versions of the system, the value returned by | |
| 126 | .Fn getlogin | |
| 127 | could not be trusted without checking the user ID. | |
| 128 | Portable programs should probably still make this check. | |
| 129 | .Sh HISTORY | |
| 130 | The | |
| 131 | .Fn getlogin | |
| 132 | function first appeared in 4.4BSD. |