1 03/31/83  syn_
 2 
 3 
 4 Function: This I/O module may be used to attach an I/O switch, x, as a
 5 synonym for another switch, y.  Thereafter, performing an operation
 6 other than attach or detach on x has the same effect as performing it
 7 on y.  There is one exception: if the attach description specifies
 8 that an operation on y is to be inhibited, performing that operation
 9 on x results in an error code.
10 
11 Entry points in the module are not called directly by users:  rather
12 the module is accessed through the I/O system.  See the Programmer's
13 Reference Manual for a general description of the input/output system
14 and a discussion of synonym attachments.
15 
16 
17 Syntax and Attach Description:
18      syn_ switch_name {-control_arg}
19 
20 
21 Arguments:
22 switch_name
23    is the name of the I/O switch, y, for which the attached switch, x,
24    is to be a synonym.
25 
26 
27 Control arguments:
28 -inhibit names, -inh names
29    specifies which I/O operations are to be inhibited.  The name
30    arguments are separated by spaces and must be chosen from the
31    following:
32             open                close
33             get_line            put_chars
34             get_chars           write_record
35             read_record         delete_record
36             rewrite_record      position
37             read_length         read_key
38             seek_key            modes
39             control
40 
41 
42 Switch Operation:  The detach operation detaches the switch x (the
43 switch attached via syn_).  It has no effect on the switch y for which
44 x is a synonym.
45 
46 
47 Inhibited Operations:  An inhibited operation returns the code
48 error_table_$no_operation.