There are several ways to invoke the interactive NCL utility: 1. Enter ncl at the shell prompt. The NCL prompt appears: % ncl <Return> ncl> 2. Enter an NCL command line. % ncl any ncl command <Return> After the command executes, you return to the shell. 3. Redirect a command script into NCL. % ncl <scripta where scripta is the name of a script that contains a sequence of NCL commands. 4. Execute a shell script containing NCL commands. Your shell script can use the exit status returned by NCL commands. % ncl_filename The following C shell script demonstrates this: #!/bin/csh ncl show routing circuit circuit-1 all attributes if ( $status != 0 ) then echo "" echo "This ncl command failed." echo "" endif This sample script uses the exit status from an NCL command to determine whether or not to echo a message. If the command fails, the shell script echoes the message. Other NCL operations include: o To abort an NCL operation, press <Ctrl/C> at the ncl> prompt. o To continue a long command to the next line, use a hyphen as the last character in the line. The _ncl> prompt is displayed on continuation lines: ncl> set node moosie routing manual network entity titles - _ncl> { 49::00-0c:08-00-2b-12-34-56:00, - _ncl> 49::00-0c:08-00-2b-12-34-57:00 } o To include comments in NCL shell scripts or as part of a command line in the interactive utility, use the exclamation point (!) or pound sign (#) character. NCL ignores hyphens within and at the end of a comment line. o To exit from NCL, enter exit, quit, or press <Ctrl/D> at the ncl> prompt.