The logname utility will write the user's login name to standard output. The login name is the string that would be returned by the getlogin(3C) function. Under the conditions where getlogin() would fail, logname will write a diagnostic message to standard error and exit with a non-zero exit status.
See environ(5) for descriptions of the following environment variables that affect the execution of logname: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following error values are returned:
0 Successful completion.
>0 An error occurred.
/etc/profile environment for user at login time
/var/adm/utmpx user and accounting information
See attributes(5) for descriptions of the following attributes:
|ATTRIBUTE TYPE||ATTRIBUTE VALUE|
env(1), login(1), getlogin(3C), utmpx(4), attributes(5), environ(5), standards(5)