Common Output Area and Log File
The Common Output Area (COA) on the terminal screen is the remaining top area
of the terminal screen not used for the User Command Area or Task Status Area.
It is a viewport on the log file.
Hermes treats the log file as a ``book'' with numbered pages.
Normally Hermes shows the current page of the book, that is the page on
which output is currently being written.
Modes of operation
The COA has two modes of operation: page mode and non-page mode.
In non-page mode the page on the screen is always the current page.
If necessary, Hermes will flip the page. The current page number is displayed at
the extreme right of the Task Status Area.
In page mode the information on the screen will stay there until the user
instructs Hermes to change the page.
Though the user does not see it, output can still be written to the log file.
In page mode the number of the displayed
page is shown to the left of the current page number.
Page mode can be switched on and off by pressing CTRL-P.
Here page 2901 is the last page, i.e. the page to which is
being written, and page number 2900 is
currently displayed in the COA.
When in non-page mode, Hermes can also scroll the COA instead of flipping
pages. This scroll mode can be switched on and off by typing
In scroll mode output is much slower than in `flip mode'. Therefore this
mode is not recommended for use with slow terminals.
Traversing the log file
The log file can be traversed in backwards direction by pressing
the CTRL-Z key (or on ANSI keyboards the PageUp key).
Paging forward is done with the CTRL-V key
(or ANSI PageDown).
Text search in the log file is done by pressing CTRL-R
(forward). Hermes then prompts the user for a search string.
(See example below.)
Searching in Hermes is case-insensitive.
A specific page number can be brought to the screen by typing ESC G,
whereafter Hermes prompts for a page number:
Signed numbers are treated as relative page numbers.
Sections of the log file can be printed by typing the ESC H
sequence. (H from Hardcopy)
Hermes then prompts for a range of pages to be printed:
The range can be specified as a single number, in which case only that page
will be printed, or using the format `start:end'.
Either start or end may be omitted, in which case the number
of the currently displayed page will be used instead.
The default range is the page currently displayed and the preceding two pages.
The printer can be selected by typing ESC P,
which causes a menu to be presented from wich a printer can be chosen.
The printer to be used can be pre-set in the Hermes
It is also possible to redirect the printer output to a file. Option
``F'' in the printer selection menu will prompt for a file name.
It is not possible to pre-set this file name in the Hermes defaults file.
The statement that the COA is a viewport on the log file is not quite true.
In fact the log file and the COA are different output streams to which tasks
can send information selectively.
Most tasks however send the same information to both the log file and the COA.
- enter or leave page mode
- display previous page and enter page mode
- display next page
- search forward for text string
- search backwards for text string
- CTRL-X S
- toggle scroll mode
- ESC G
- go to specified page number
- ESC H
- make hardcopy of specified page numbers
- ESC P
- select a printer for the hardcopy print command
- ESC <
- go to first page
- ESC >
- go to last page