coreutils: logname invocation

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1 20.2 ‘logname’: Print current login name
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1 
1 ‘logname’ prints the calling user’s name, as found in a
1 system-maintained file (often ‘/var/run/utmp’ or ‘/etc/utmp’), and exits
1 with a status of 0.  If there is no entry for the calling process,
1 ‘logname’ prints an error message and exits with a status of 1.
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11    The only options are ‘--help’ and ‘--version’.  ⇒Common
 options.
1 
1    An exit status of zero indicates success, and a nonzero value
1 indicates failure.
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