1NODEATTR(1)                        NODEATTR                        NODEATTR(1)
2
3
4

NAME

6       nodeattr - query genders file
7

SYNOPSIS

9       nodeattr [-f genders] [-q | -c | -n | -s] [-X exclude_query] query
10       nodeattr [-f genders] [-q | -c | -n | -s] -A
11       nodeattr [-f genders] [-v] [node] attr[=val]
12       nodeattr [-f genders] -Q [node] query
13       nodeattr [-f genders] -V [-U] attr
14       nodeattr [-f genders] -l [node]
15       nodeattr [-f genders] -k
16       nodeattr [-f genders] -d genders
17       nodeattr [-f genders] --expand
18       nodeattr [-f genders] --compress
19

DESCRIPTION

21       When  invoked  with  the -q , -c , -n , or -s arguments, nodeattr reads
22       the genders file and outputs a list of nodes that match  the  specified
23       query.  The nodes are listed in hostlist format, comma separated lists,
24       newline separated lists, or space separated lists  respectively.   Gen‐
25       ders  queries  will query the genders database for a set of nodes based
26       on the  union,  intersection,  difference,  or  complement  of  genders
27       attributes  and  values.  The set operation union is represented by two
28       pipe symbols ('||'), intersection by two ampersand symbols ('&&'), dif‐
29       ference  by  two minus symbols ('--'), and complement by a tilde ('~').
30       Parentheses may be used to change the  order  of  operations.   The  -X
31       argument and query can be used to exclude nodes from the resulting out‐
32       put.  A query can be replaced with the -A option to cause  nodeattr  to
33       print all the nodes listed in the genders database.
34
35       When  called  with  a node name (optional) and attribute name, nodeattr
36       returns 0 to the environment if the node has the attribute; else 1.  If
37       -v  is present, the attribute name and any value (see below) is printed
38       on the standard output.  If a node name is  not  specified,  the  local
39       host is assumed.
40
41       When  called with the -Q argument, nodeattr will check if the node name
42       (optional) is met by the attribute and value  conditions  specified  in
43       the  query.  If the conditions are met, nodeattr returns 0 to the envi‐
44       ronment; else 1.  The query format is identical to  the  format  listed
45       above.  If a node name is not specified, the local host is assumed.
46
47       The -V option causes nodeattr to print all of the values that exist for
48       a particular attribute.  Also specifing -U with -V causes  nodeattr  to
49       print out only unique values for the particular attribute.
50
51       The  -l option causes nodeattr to print the attributes of the specified
52       node.  If no node is listed, all attributes in  the  genders  file  are
53       listed.
54
55       The  -k option checks the genders file for parse errors and proper for‐
56       matting.  If errors are found, information about the error will be out‐
57       put to standard error.
58
59       Nodeattr  will  always  check the default genders file, but a different
60       genders file can be specified with the -f option.
61
62       The -d option allows the specified genders database to be  compared  to
63       the  filename  indicated  by the -f option or the default genders data‐
64       base.  The differences contained in the specified database will be out‐
65       put to standard error.
66
67       The  --expand  option  will  take  a  genders database, expand all hos‐
68       tranges, and output a new genders database.   The  subsequent  database
69       will be identical to the first, but every node will be listed on a sep‐
70       arate line.  This option may be useful for debugging or determining the
71       difference between databases.
72
73       The  --compress  is  opposite of the --expand option.  It will output a
74       new identical genders database with hostranges of nodes with  identical
75       attributes.   Depending  on  the  setup  of  your genders database, the
76       resulting database may be longer or shorter.  This option may be useful
77       as a beginning step to compressing an existing genders database.
78
79       Attribute names may optionally appear in the genders file with an equal
80       sign followed by a value.  Nodeattr ignores these  values  except  when
81       the  -v  option requests that the value, if any, be displayed; and when
82       an attribute is specified on the command line with a  value,  in  which
83       case  only  an  attribute  with the specified value in the genders file
84       will match.
85

EXAMPLES

87       Retrieve a comma separated list of all login nodes:
88
89              nodeattr -c login
90
91       Retrieve a hostlist formatted list of all login nodes:
92
93              nodeattr -q login
94
95       Retrieve a comma separated list of nodes with 4 cpus:
96
97              nodeattr -c cpus=4
98
99       Retrieve a comma separated list of all login and management nodes:
100
101              nodeattr -c "login||mgmt"
102
103       Retrieve a comma separated list of all login nodes with 4 cpus:
104
105              nodeattr -c "login&&cpus=4"
106
107       Retrieve a comma separated list of all nodes that are not login or man‐
108       agement nodes:
109
110              nodeattr -c "~(login||mgmt)"
111
112       To use nodeattr with pdsh to run a command on all fddi nodes:
113
114              pdsh -w`nodeattr -c fddi` command
115
116       To  use  nodeattr  in  a ksh script to collect a list of users on login
117       nodes:
118
119              for i in `nodeattr -n login`; do rsh $i who; done
120
121       To verify whether or not this node is a head node:
122
123              nodeattr head && echo yes
124
125       To verify whether or not this node is a head node and ntpserver:
126
127              nodeattr -Q "head&&ntpserver" && echo yes
128

FILES

130       /etc/genders
131

SEE ALSO

133       libgenders(3)
134
135
136
137LLNL                              August 2003                      NODEATTR(1)
Impressum