NODEATTR(1)							     NODEATTR							       NODEATTR(1)

NAME

       nodeattr - query genders file

SYNOPSIS

       nodeattr [-f genders] [-q | -c | -n | -s] [-X exclude_query] query
       nodeattr [-f genders] [-q | -c | -n | -s] -A
       nodeattr [-f genders] [-v] [node] attr[=val]
       nodeattr [-f genders] -Q [node] query
       nodeattr [-f genders] -V [-U] attr
       nodeattr [-f genders] -l [node]
       nodeattr [-f genders] -k
       nodeattr [-f genders] -d genders
       nodeattr [-f genders] --expand
       nodeattr [-f genders] --compress

DESCRIPTION

       When  invoked with the -q , -c , -n , or -s arguments, nodeattr reads the genders file and outputs a list of nodes that match the specified
       query.  The nodes are listed in hostlist format, comma separated lists, newline separated lists, or  space  separated  lists  respectively.
       Genders	queries  will query the genders database for a set of nodes based on the union, intersection, difference, or complement of genders
       attributes and values.  The set operation union is represented by two pipe symbols ('||'), intersection by two  ampersand  symbols  ('&&'),
       difference  by  two minus symbols ('--'), and complement by a tilde ('~').  Parentheses may be used to change the order of operations.  The
       -X argument and query can be used to exclude nodes from the resulting output.  A query can be replaced with the -A option to cause nodeattr
       to print all the nodes listed in the genders database.

       When  called  with  a node name (optional) and attribute name, nodeattr returns 0 to the environment if the node has the attribute; else 1.
       If -v is present, the attribute name and any value (see below) is printed on the standard output.  If a node name  is  not  specified,  the
       local host is assumed.

       When called with the -Q argument, nodeattr will check if the node name (optional) is met by the attribute and value conditions specified in
       the query.  If the conditions are met, nodeattr returns 0 to the environment; else 1.  The query format is identical to the  format  listed
       above.  If a node name is not specified, the local host is assumed.

       The  -V option causes nodeattr to print all of the values that exist for a particular attribute.  Also specifing -U with -V causes nodeattr
       to print out only unique values for the particular attribute.

       The -l option causes nodeattr to print the attributes of the specified node.  If no node is listed, all attributes in the genders file  are
       listed.

       The  -k	option	checks	the genders file for parse errors and proper formatting.  If errors are found, information about the error will be
       output to standard error.

       Nodeattr will always check the default genders file, but a different genders file can be specified with the -f option.

       The -d option allows the specified genders database to be compared to the filename indicated by the -f option or the default genders  data-
       base.  The differences contained in the specified database will be output to standard error.

       The  --expand  option will take a genders database, expand all hostranges, and output a new genders database.  The subsequent database will
       be identical to the first, but every node will be listed on a separate line.  This option may be useful for debugging  or  determining  the
       difference between databases.

       The --compress is opposite of the --expand option.  It will output a new identical genders database with hostranges of nodes with identical
       attributes.  Depending on the setup of your genders database, the resulting database may be longer or shorter.  This option may	be  useful
       as a beginning step to compressing an existing genders database.

       Attribute  names  may  optionally  appear in the genders file with an equal sign followed by a value.  Nodeattr ignores these values except
       when the -v option requests that the value, if any, be displayed; and when an attribute is specified on the command line with a	value,	in
       which case only an attribute with the specified value in the genders file will match.

EXAMPLES

       Retrieve a comma separated list of all login nodes:

	      nodeattr -c login

       Retrieve a hostlist formatted list of all login nodes:

	      nodeattr -q login

       Retrieve a comma separated list of nodes with 4 cpus:

	      nodeattr -c cpus=4

       Retrieve a comma separated list of all login and management nodes:

	      nodeattr -c "login||mgmt"

       Retrieve a comma separated list of all login nodes with 4 cpus:

	      nodeattr -c "login&&cpus=4"

       Retrieve a comma separated list of all nodes that are not login or management nodes:

	      nodeattr -c "~(login||mgmt)"

       To use nodeattr with pdsh to run a command on all fddi nodes:

	      pdsh -w`nodeattr -c fddi` command

       To use nodeattr in a ksh script to collect a list of users on login nodes:

	      for i in `nodeattr -n login`; do rsh $i who; done

       To verify whether or not this node is a head node:

	      nodeattr head && echo yes

       To verify whether or not this node is a head node and ntpserver:

	      nodeattr -Q "head&&ntpserver" && echo yes

FILES

       /etc/genders

SEE ALSO

       libgenders(3)

LLNL
								    August 2003 						       NODEATTR(1)