coreutils: hostname invocation

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1 21.5 ‘hostname’: Print or set system name
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1 
1 With no arguments, ‘hostname’ prints the name of the current host
1 system.  With one argument, it sets the current host name to the
1 specified string.  You must have appropriate privileges to set the host
1 name.  Synopsis:
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1      hostname [NAME]
1 
11    The only options are ‘--help’ and ‘--version’.  ⇒Common
 options.
1 
1    ‘hostname’ is not installed by default, and other packages also
1 supply a ‘hostname’ command, so portable scripts should not rely on its
1 existence or on the exact behavior documented above.
1 
1    An exit status of zero indicates success, and a nonzero value
1 indicates failure.
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