1 10/11/83  read_mail (forward) request:  exec_com, ec
 2 
 3 Syntax:  ec ec_path {ec_args}
 4 
 5 
 6 Syntax as an active request:  [ec ec_path {ec_args}]
 7 
 8 
 9 Function:  executes a program written in the exec_com language which is
10 used to pass request lines to the sub-request loop of the forward
11 request and to pass input lines to requests which read input.  As an
12 active request, the exec_com program specifies a return value of the
13 exec_com request by use of the &return statement.
14 
15 
16 Arguments:
17 ec_path
18    is the pathname of an exec_com program.  The suffix "rdmec" is added
19    to the pathname if necessary.
20 ec_args
21    are optional arguments to the exec_com program and are substituted
22    for parameter references in the program such as &1.
23 
24 
25 Notes:
26 If ec_path does not contain a "<" or ">" character, forward will search
27 for the exec_com program using the mail_system search list.  The
28 default content of this search list is:
29       -working_dir
30       >udd>[user project]>[user name]>[user name].mlsys
31 
32 For a description of the exec_com language (both version 1 and
33 version 2), type:
34    .. help v1ec v2ec
35 
36 When evaluating a forward exec_com program, subsystem active requests
37 are used rather than Multics active functions when evaluating the
38 &[...] construct and the active string in an &if statement.  The
39 forward execute active request may be used to evaluate Multics active
40 strings within the exec_com.
41 
42 
43 Limitation:
44 In the present implementation, any errors detected during execution of
45 an exec_com within the forward sub-request loop will abort the request
46 line in which the exec_com request was invoked.