I/O redirection may be done even if I/O has already been redirected.
For example, say you have created a command file named SHOW, which
contains the following:
parm showdest="$STDLIST"
showme
showout >!showdest
showvar
showjob >>!showdest ;job=!hpuser.!hpaccount
|
Now let's say you set a file equation for printer LP602 and invoke
SHOW as follows:
After variable substitution and I/O redirection, this results in the
following sequence of commands and output destinations:
showme output to lp602 (spoolfile)
showout output to a temporary file named outfile
showvar output to lp602 (a new spoolfile)
showjob output appended to the temporary file outfile
Output from the showme and showvar commands goes to the device
defined by the file equation for lp602.
Output from the showout command is redirected to the file
outfile and output from showjob is appended to outfile.
This occurs because the entire show command file has its output
redirected to LP602. But inside the command file, the showout and
showjob commands redirect output (again) to the temporary file
name outfile.