1 01/24/82  Standard subsystem request:  if
 2 
 3 Syntax:  if EXPR -then LINE1 {-else LINE2}
 4 
 5 
 6 Syntax as an active request:  if EXPR -then STR1 {-else STR2}
 7 
 8 
 9 Function:  conditionally executes one of two request lines depending on
10 the value of an active string.  As an active request, returns one of
11 two character strings to the subsystem request processor depending on
12 the value of an active string.
13 
14 
15 Arguments:
16 EXPR
17    is the active string which must evaluate to either "true" or
18    "false".  The active string is constructed from subsystem active
19    requests and Multics active strings (using the subsystem's execute
20    active request).
21 LINE1
22    is the subsystem request line to execute if EXPR evaluates to
23    "true".  If the request line contains any request processor
24    characters, it must be enclosed in quotes.
25 STR1
26    is returned as the value of the if active request if the EXPR
27    evaluates to "true".
28 
29 
30 LINE2
31    is the subsystem request line to execute if EXPR evaluates to
32    "false".  If omitted and EXPR is "false", no additional request line
33    is executed.  If the request line contains any request processor
34    characters, it must be enclosed in quotes.
35 STR2
36    is returned as the value of the if active request if the EXPR
37    evaluates to "false".  If omitted and the EXPR is "false", a null
38    string is returned.