LOGNAME(P) POSIX Programmer's Manual LOGNAME(P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAMElogname - return the user's login name
SYNOPSISlognameDESCRIPTION
The logname utility shall write the user's login name to standard out‐
put. The login name shall be the string that would be returned by the
getlogin() function defined in the System Interfaces volume of
IEEE Std 1003.1-2001. Under the conditions where the getlogin() func‐
tion would fail, the logname utility shall write a diagnostic message
to standard error and exit with a non-zero exit status.
OPTIONS
None.
OPERANDS
None.
STDIN
Not used.
INPUT FILES
None.
ENVIRONMENT VARIABLES
The following environment variables shall affect the execution of log‐
name:
LANG Provide a default value for the internationalization variables
that are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
ables for the precedence of internationalization variables used
to determine the values of locale categories.)
LC_ALL If set to a non-empty string value, override the values of all
the other internationalization variables.
LC_CTYPE
Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as
opposed to multi-byte characters in arguments).
LC_MESSAGES
Determine the locale that should be used to affect the format
and contents of diagnostic messages written to standard error.
NLSPATH
Determine the location of message catalogs for the processing of
LC_MESSAGES .
ASYNCHRONOUS EVENTS
Default.
STDOUT
The logname utility output shall be a single line consisting of the
user's login name:
"%s\n", <login name>
STDERR
The standard error shall be used only for diagnostic messages.
OUTPUT FILES
None.
EXTENDED DESCRIPTION
None.
EXIT STATUS
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
Default.
The following sections are informative.
APPLICATION USAGE
The logname utility explicitly ignores the LOGNAME environment variable
because environment changes could produce erroneous results.
EXAMPLES
None.
RATIONALE
The passwd file is not listed as required because the implementation
may have other means of mapping login names.
FUTURE DIRECTIONS
None.
SEE ALSO
id , who , the System Interfaces volume of IEEE Std 1003.1-2001, getlo‐
gin()COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 LOGNAME(P)
