1 10/02/81  value_defined, vdf
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 3 Syntax:  vdf name {-control_args}
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 6 Syntax as active function:  [vdf name {-control_args}]
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 9 Function:  returns true if name has a value set by the value_set (vs)
10 command or by "value_get -call", false otherwise.  The value can be
11 perprocess or reside in a value segment (type "help value_get").
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13 
14 Arguments:
15 name
16    is a character string.  It can be -name STR to specify a name
17    beginning with a minus sign, to distinguish it from a control
18    argument.
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20 
21 Control arguments:
22 -pathname PATH, -pn PATH
23    specifies a value segment other than the current default one,
24    without changing the default.  For more information, see "Notes on
25    value segment".
26 -permanent, -perm
27    returns true only if a value is defined in the value segment,
28    regardless of whether a perprocess value exists.  The default is to
29    return true for either a perprocess or a permanent value.
30 -perprocess, -pp
31    returns true only if a perprocess value is defined.
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33 
34 Access required:
35 r to the value segment, except for perprocess values.  Lack of r
36 access is equivalent to no value defined in the segment.
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39 Notes:  See the related command/active functions value_get (vg),
40 value_set (vs), value_delete (vdl), value_list (vls), value_set_path
41 (vsp), and value_path (vp).