Hercules: Installation and Operation

# Hercules Version 4: Installation and Operation

## Contents

> Building and Installing

> - Building from source on Windows
>   - Windows Pre-built binaries
> - Building from source on Mac OS X
> - Building from source on Linux and macOS (High Sierra and newer)

> Configuration

> Creating DASD volumes

> Operating Procedure

> - Command line arguments
> - Using the keyboard
> - Panel commands
> - The .RC ("run commands") file
> - HAO ("Hercules Automatic Operator")

> Technical Support

## Building and Installing

By far easiest and most direct way to build Hercules is to use Bill Lewis's fantastic Hercules Helper tool, and not the below manual method.

Hercules Helper (for both Windows and non-Windows) completely automates the entire build process of downloading and installing all of the needed pieces and running all of needed commands to create a working Hercules. Simply download Bill's tool and enter a few simple commands, and within minutes you should have a working Hercules on your system.

### Building from source - Windows

If you wish to build Hercules yourself manually however, the procedure is as follows:

1. Clone the Hercules source code git repository (recommended), or download the source code .ZIP file from Github (discouraged!).

           git clone  https://github.com/SDL-Hercules-390/hyperion.git  <directory-name>

   If you don't have `git` on your system, you will need to install it.

   Note: By downloading the source code .zip file (discouraged!) or by cloning the repository (recommended) you agree to the terms of the Hercules Q Public Licence.

2. Hercules for Windows is built using the Microsoft Visual C/C++ (MSVC) compiler. Fish has updated manual build instructions for VS2015 and greater (as well as VS2008 too) on his MSVC Hercules Build Instructions web page, although as mentioned above, the by far easiest most reliable way to build Hercules on Windows is to use Bill Lewis's "Hercules Helper for Windows" tool, which is designed to build Hercules using much more current versions of Visual Studio.
3. Be sure to read the Release Notes with every new release too, which contains important late-breaking information about each new release.

### Windows pre-built binaries:

1. Download one of the pre-built Official Release binaries from GitHub.
2. (Optional) You might also want to install Fish's Hercules GUI for Windows and/or one or more of his other Hercules products.

### Building from source - Mac OS X

Important - Not Recently Tested. May be obsolete.

1. Install Xcode from the App Store.
2. Install Homebrew using the procedure described at http://brew.sh/
3. Use these commands to install pre-requisite software:
   `brew install gnu-sed`
4. Proceed with Building from source - Linux and macOS below.

### Building from source - Linux and macOS (High Sierra and newer)

Important: Please read everything before doing anything. Don't be bashful about asking for help.

Important: You must use at least version 6.2.0 of the gcc compiler and associated glibc2 library. Refer to the Hercules Frequently-Asked Questions page for required compiler and other software levels.

1. Download the source code .ZIP file from Github, or even better, clone the repository. (Note: building from the source code .zip file is strongly discouraged. Instead, it is highly recommended that you clone the git repository and build from that instead. This allows the exact version of the source code to be determined, which is very helpful should a problem need to be diagnosed.)

           git clone  https://github.com/SDL-Hercules-390/hyperion.git  <directory-name>

   Note: By downloading the .zip file (or cloning the repository) you agree to the terms of the Q Public Licence.

2. Be sure to read the Release Notes with every new release, which contains important late-breaking information about each new release.
3. Install the required packages appropriate for your system.

   - Debian / Ubuntu / Mint / etc

     `sudo apt-get -y install git wget time
     sudo apt-get -y install build-essential cmake flex gawk m4 autoconf automake libtool-bin libltdl-dev
     sudo apt-get -y install libbz2-dev zlib1g-dev
     sudo apt-get -y install libcap2-bin`

     Note: For Regina REXX to run the included tests:

     `sudo apt-get -y install libregina3-dev`

   - Elbrus Linux (similar to Debian)

     `sudo apt-get -y install git wget time
     sudo apt-get -y install build-essential cmake flex gawk m4 autoconf automake libtool
     sudo apt-get -y install bzip2 zlib
     sudo apt-get -y install libcap`

   - Arch / Manjaro

     `sudo pacman -S --needed --noconfirm git wget
     sudo pacman -S --needed --noconfirm base-devel make cmake flex gawk m4 autoconf automake
     sudo pacman -S --needed --noconfirm bzip2 zlib`

   - Fedora

     `sudo dnf -y install git wget
     sudo dnf -y install gcc make cmake flex gawk m4 autoconf automake libtool-ltdl-devel
     sudo dnf -y install bzip2-devel zlib-devel`

   - CentOS / AlmaLinux / Rocky Linux 8+ / Red Hat RHEL 9

     `sudo yum -y install git wget time
     sudo yum -y install gcc make cmake flex gawk m4 autoconf automake libtool-ltdl-devel
     sudo yum -y install bzip2-devel zlib-devel`

     Note: On CentOS 9, the following command is required before installing the packages:

     `sudo yum config-manager --set-enabled crb`

     Note: On Red Hat RHEL 9, the following command is required before installing the packages:
     (refer here for more information)

     `sudo subscription-manager repos --enable codeready-builder-for-rhel-9-$(arch)-rpms`

   - CentOS 7

     `sudo yum -y install git wget
     sudo yum -y install gcc make flex gawk m4 autoconf automake libtool-ltdl-devel
     sudo yum -y install bzip2-devel zlib-devel`

     Note: On CentOS 7, there is no package for CMAKE 3.x, it must be built from source.

   - openSUSE (15.1+)

     `sudo zypper install -y git
     sudo zypper install -y -t pattern devel_basis autoconf automake cmake flex gawk m4 libtool
     sudo zypper install -y -t pattern bzip2 libz1 zlib-devel
     sudo zypper install -y libcap-progs`

   - Apple Darwin (macOS High Sierra, Mojave, Catalina, Big Sur, etc.) with Homebrew

     `xcode-select --install
     /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
     `

     brew install wget gsed
     brew install cmake autoconf automake libtool

     Note: So configure/make will find ltdl.h and libltdl:

     `export CFLAGS="$CFLAGS -I$(find $(brew --cellar libtool) -type d -name "include" | sort -n | tail -n 1)"
     export LDFLAGS="$LDFLAGS -L$(find $(brew --cellar libtool) -type d -name "lib" | sort -n | tail -n 1)"`

     And include these options to configure:

     `--disable-getoptwrapper
     --without-included-ltdl`

   - Apple Darwin (macOS Big Sur) with MacPorts

     Information on installing MacPorts may be found here.

     `sudo port install wget gsed
     sudo port install cmake autoconf automake libtool`

     Note: So configure/make will find ltdl.h and libltdl:

     `export CFLAGS=-I/opt/local/include LDFLAGS=-L/opt/local/lib`

   - FreeBSD

     `sudo pkg install -y bash git wget
     sudo pkg install -y gmake autoconf automake cmake flex gawk m4 libltdl
     sudo pkg install -y bzip2`

     Note: Bash is required by parts of the build apparatus.

     Note: So configure/make will find ltdl.h and libltdl:

     `export CFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib`

   - OpenBSD is not currently supported

4. Verify you have all of the correct versions of the more important packages installed:

   `./util/bldlvlck`

   Please note that SDL Hyperion comes pre-delivered with an already pre-generated `./configure` script, so doing a `./autogen.sh` is not necessary and is in fact now strongly discouraged. An autogen would only be necessary if you were to manually make some changes to the Hercules default `Makefile.am` and/or `configure.ac` files (which under normal circumstances you should never need to do).

5. Download and build all External Packages, if needed:
   Hercules links with several pre-built "External Package" static link libraries that have been pre-built for you and come distributed with Hercules (i.e. they are a part of the Hercules repository).
   Currently all of the external package static link libraries for the Intel x86 (32-bit) and x64 (64-bit) architectures for both Windows and Linux for both normal optimized Release builds as well as unoptimized Debug builds are already provided as part of the distribution. Thus to build Hercules you should not need to do anything special. Simply build Hercules just as you normally would.
   In some unusual situations however, you MIGHT need to rebuild ALL existing external packages for your particular system. Exactly what those situations are and what causes them to occur is unclear, but one thing is certain: it will never hurt to build all of the external packages anyway just to be safe.
   If you wish to modify or debug any of the external packages themselves (or need to build a non-Intel x86/x64 architecture build of Hercules however, such as arm, mips, ppc, sparc, xscale, etc), then you will need to manually build each of the external packages first in order to create the static link libraries that Hercules will need to link with, before you can then build Hercules.
   For more detailed External Package build information please refer to the README.EXTPKG document.

6. Configure Hercules for your system:

   `./configure`

   By default, the configure script will attempt to guess appropriate compiler optimization flags for your system. If its guesses turn out to be wrong, you can either specify your own optimization flags with `--enable-optimization=FLAGS` (preferred) or else as a last resort disable all optimization by passing the `--disable-optimization` option instead (not recommended). For additional configuration options, run: `./configure --help=short`.

   For Apple macOS, these additional configure switches are recommended:

   `--disable-getoptwrapper
   --without-included-ltdl`

7. Build the executables:

   `make`

8. (Optional) Install the programs:

   `sudo make install`

   This is an optional step because once Hercules is built, you should be able to run Hercules directly from the Hercules build directory itself without needing to install anything beforehand. But if you want to officially install it somewhere, then by all means do so.

   It should be mentioned however, that if you do decide to run directly out of the build directory, you should first set the 'cap_sys_nice' capabilities on the Hercules executables and start Hercules as root. This will allow Hercules to properly set the priorities of its internal threads:

       sudo setcap 'cap_sys_nice=eip' ./hercules
       sudo setcap 'cap_sys_nice=eip' ./herclin
       sudo setcap 'cap_net_admin+ep' ./hercifc

   You don't need to do this if you do `sudo make install` however since the makefile does this for you. You only need to do this when you decide to not install the results of the build and run directly out of the build directory instead.

## Configuration

You will need to amend the configuration file hercules.cnf to reflect your device layout and intended mode of operation (S/370, ESA/390, or z/Architecture). See the Hercules Configuration File page for a complete description.

## Creating DASD volumes

The Creating Hercules DASD page describes various methods of creating and loading virtual DASD volumes. The compressed CKD DASD support is described in this page.

## Operating Procedure

Note! If you intend to run any licensed software on your PC using Hercules, it is your responsibility to ensure that you do not violate the software vendor's licensing terms!
Note: Hercules requires privileged access to your host's networking devices in order for Hercules networking to work properly. If your configuration contains any networking devices, then Hercules must be started with Administrative (root) privileges. If Hercules is not started with Administrative (root) privileges then initialization of your networking devices will fail and your guest's networking will not work properly. If your guest does not need access to your host's network Hercules should be run as a normal unprivileged user (the default).

Hercules can operate in either of two modes: (semi-)graphical "panel" mode or simple non-graphical standard command-line mode.

The default semi-graphical "panel" mode of operation is invoked by the "hercules.exe" executable, and the non-graphical standard command-line mode by the "herclin.exe" executable. They are both exactly identical except for how the terminal screen is managed.

In the normal (default) semi-graphical "panel" mode, hercules.exe draws to screen directly itself, and does not rely on any terminal manager functionality (Terminal or Command-Prompt program). It paints (draws) messages and other information (such as its command line and CPU status line) on specific screen lines starting at specific columns, etc:

hercules.exe managed Hardware Machine Console (HMC)

It relies on certain keystrokes (such as the PageUp and PageDown keys, etc) to perform actions such as displaying previously issued messages and switching to its alternate semi-graphical display panel via the Esc. key (which shows an overall summary of the machine's state, such as its current set of register values, list of devices, etc):

hercules.exe managed semi-graphical panel

When started in standard command-line mode via "herclin.exe", the terminal screen is managed completely by your host operating system's terminal management software. Hercules does not paint the screen itself at all. It simply issues messages to "stdout" just like any other command-line program and your operating system's terminal management software decides where on the screen that line will be displayed. Additionally, Hercules does not read directly from the command-ine itself either. Instead, it simply reads from "stdin" and processes the commands it reads. Your host operating system's terminal manager is in charge of managing the command-line, not Hercules:

Unmanaged "herclin.exe" terminal screen,
scrolled back several screens to see previously issued terminal commands.

In standard "herclin.exe" command-line mode, Hercules operates just like any other normal command-line program, and you can use the Terminal's scroll bar (if it has one) and/or your mouse's scroll wheel to scroll the screen backward or forward to see previously issued messages and/or commands and their responses. Your host operating system's terminal manager is in charge of painting the screen and reading the command line, not Hercules.

#### Command line arguments

To start Hercules in the default "panel" operating mode, enter this command at the host's command prompt:

> `

>         hercules  [ -f filename ]           |  [ --config=filename ]
>                   [ -o logfile]             |  [ --output=logfile ]  |  [ --logfile=logfile ]
>                   [ -r rcfile ]             |  [ --rcfile=rcfile ]
>                   [ -b logofile ]           |  [ --herclogo=logofile ]
>                   [ -d ] DEPRECATED         |  [ --daemon ] DEPRECATED
>                   [ -n ]                    |  [ --NoUI ]
>                   [ -e ]                    |  [ --externalgui ]
>                   [ -p modpath ]            |  [ --modpath=modpath ]
>                   [ -l modname ] ...        |  [ --ldmod=modname ] ...
>                   [ -s symbol=value ] ...   |  [ --defsym=symbol=value ] ...
>                   [ -v ]                    |  [ --verbose ]
>                   [ -h ]                    |  [ --help[=type] ]
>                   [ -t[factor]]             |  [ --test[=factor]]

>                   [ > logfile ]

> `

where:

> `filename`

>   is the name of the configuration file. The default, if none is specified, is hercules.cnf. The default may be overridden via the "`HERCULES_CNF`" environment variable. If the value "none" is specified as the name of the configuration file, then Hercules is started without a configuration file using internal default values and no devices. Alternatively, specifying the filename as "`NUL`" on Windows or "`/dev/null`" on Linux means the same thing as specifying "none".

> `logfile`

>   is the name of the optional log file. A log file receives a copy of all messages displayed on the Hercules control panel. PLEASE NOTE: providing a logfile is extremely important for bug reporting and problem analysis purposes! It is strongly recommended that you always specify this option!

> `rcfile`

>   is the name of the Hercules .rc run commands file. The run commands file automatically executes panel commands upon startup. If not specified, the value of the "`HERCULES_RC`" environment variable is used. If no environment variable is defined, the default value "hercules.rc" is used. If the default "hercules.rc" file is not found, then the value "none" is used, indicating an .rc file will not be used.

> `logofile`

>   is the name of the Hercules logo file. The logo file is the initial welcome screen presented when a TN 3270 terminal connects to a hercules 3270 device.

> `--daemon` (deprecated)

>   This option has been deprecated due to its confusing name. Please use the below `'--NoUI'` option instead.

> `--NoUI`

>   specifies that Hercules is to be run invisibly in "No User Interface" mode, wherein it runs in the backgroud without any attached console or keyboard.

>   Please Note that Hercules's "No User Interface mode" is not the same as e.g. Linux's daemon mode. It is quite different. Refer to our "Running Hercules in "No User Interface" mode" web page for more information.

> `--externalgui`

>   indicates Hercules is to be controlled by an External GUI.

> `modpath`

>   is the directory from which dynamic modules are to be loaded. This option overrides both the `MODPATH` configuration file statement and system defaults. The system default varies depending on the host platform where Hercules is being run.

> `modname`

>   is the name of an additional dynamic module to be loaded at startup. More than one additional module may be specified, although each must be preceded with the `-l` option specifier.

> `symbol=value`

>   the name of a symbol and its associated value to be used in configuration file processing or panel commands. See the command 'defsym' for more information on using symbols. The '-s' option may be repeated. Note: 'value' may be quoted to contain embedded blanks.

> `--verbose`

>   sets the message-level to verbose. This is the same as entering the command `msglvl +verbose`.

> `--help[=type]`

>   displays help regarding the syntax of command-line arguments and, optionally, other information as well if the optional help `type` is also specified.

>   The optional `type` value identifies what type of help you want to display. Valid values are: `short`, `long`, `version` or `build`. Additionally, `all` and `full` are also accepted as aliases for `long`.

>   The `short` help option displays just the syntax of the the command line arguments. The `version` help option displays version information. The `build` option displays some of the more important optional features that Hercules was either built with or without. The `long`, `all` and `full` options displays all three types. The default is `short` (i.e. only the command-line syntax is shown).

> `--test[=factor]`

>   starts Hercules in test mode, activating special .rc file script commands used only by QA test scripts. Normal Hercules use should never specify this switch.

>   `factor` is an optional test timeout factor within the range 1.0 to 14.3. The test timeout factor is used to adjust each test script's specified timeout value to compensate for the speed of the system on which they are running.

>   Use a factor greater than 1.0 on slower systems to slightly increase timeout values giving each test more time to complete.

>   Please note that due to manner in which command line arguments are parsed this option must be specified as one argument. Thus "-t2.0" is correct whereas "-t 2.0" is not. Oftentimes it is easier to use the long `--test=factor` syntax instead.

>   Test timeout values (specified as optional arguments on the special runtest script command) are a safety feature designed to prevent runaway tests from never ending. Normally tests end automatically the very moment they are done.

> `logfile`

>   is the name of the optional (but highly recommended!) log file. The log file receives a copy of all messages displayed on the control panel and is extremely important to have for problem analysis and bug reporting.

Next connect a tn3270 client to the console port (normally port 3270). The client will be connected to the first 3270 device address specified in the configuration file (this should be the master console address). If your master console is a 1052 or 3215, connect a telnet client instead of a tn3270 client.

Now you can enter an ipl command from the control panel.

#### Using the keyboard

In the default "panel" operating mode, the main Hercules screen contains a scrollable list of messages with a command input area and system status line at the bottom of the screen. (see further above)

To scroll through the messages, use either the Page Up or Page Down keys, the Ctrl + Up Arrow or Ctrl + Down Arrow keys, or the Home or End and/or the Ctrl + Home or Ctrl + End keys.

Use the Insert key to switch between insert and overlay mode when typing in the command input area. Use the Home and End keys to move to the first or last character of the command you are typing, or the use the left/right arrow keys to move to a specific character. Use the Escape key to erase the input area.

Pressing Escape when the command input area is already empty causes the screen to switch to the semi-graphical "New Panel" display mode, which shows the overall status of the system and devices.

When in the semi-graphical "New Panel" display mode there is no command input area. Instead, single character "hot keys" are used to issue some of the more common functions such as starting or stopping the CPU. The hot-keys are those which are highlighted. Pressing the '?' key displays brief help information on how to use the semi-graphical panel.

Normal cursor handling
Key | Action
--- | ---
Esc | Erases the contents of the command input area. If the command input area is already empty, switches to semi-graphical New Panel.
Del | Deletes the character at the cursor position.
Backspace | Erases the previous character.
Insert | Toggles between insert mode and overlay mode.
Tab | Attempts to complete the partial file name at the cursor position in the command input area. If more than one possible file exists, a list of matching file names is displayed.
Home | Moves the cursor to the start of the input in the command input area. If the command input area is empty, scrolls the message area to the top.
End | Moves the cursor to the end of the input in the command input area. If the command input area is empty, scrolls the message area to the bottom.
Page Up | Scrolls the message area up one screen.
Page Down | Scrolls the message area down one screen.
Up arrow | Recalls previous command into the input area.
Down arrow | Recalls next command into the input area.
Right arrow | Moves cursor to next character of input area.
Left arrow | Moves cursor to previous character of input area.
Ctrl + Up arrow | Scrolls the message area up one line.
Ctrl + Down arrow | Scrolls the message area down one line.
Ctrl + Home | Scrolls the message area to the top.
Ctrl + End | Scrolls the message area to the bottom.

The following additional keyboard functions are effective when the Hercules Extended Cursor Handling feature (OPTION_EXTCURS) is activated at compile time. At present, this feature is activated on the Windows platform only:

Extended cursor handling
Key | Action
--- | ---
Alt + Up arrow | Moves cursor up one row.
Alt + Down arrow | Moves cursor down one row.
Alt + Right arrow | Moves cursor right one column.
Alt + Left arrow | Moves cursor left one column.
Tab | If cursor is outside the command input area, moves cursor to the start of the input in the command input area. Otherwise behaves as described in previous table.
Home | If cursor is outside the command input area, moves cursor to the start of the input in the command input area. Otherwise behaves as described in previous table.
End | If cursor is outside the command input area, moves cursor to the end of the input in the command input area. Otherwise behaves as described in previous table.

#### Panel commands

The following is what is displayed on the Hercules hardware console (HMC) in response to the '?' command being entered. Please note that it may not be completely accurate or up-to-date. Enter the '?' command for yourself for a more complete, accurate and up-to-date list of supported panel commands:

         Command               Description
         ----------------      -----------------------------------------------
         !message             *SCP priority message
         #                     Silent comment
         $locate               Display sysblk, regs or hostinfo
         $runtest             *Start the test if test mode is active
         $test                *Your custom command (*DANGEROUS!*)
         $zapcmd              *Enable/disable command (*CAREFUL!*)
         *                     Loud comment
         .reply               *SCP command
         ?                     alias for help
         abs                  *Display or alter absolute storage
         aea                   Display AEA tables
         aia                   Display AIA fields
         alrf                  Command deprecated. Use facility command instead
         ar                    Display access registers
         archlvl              *Set or Query current Architecture Mode
         archmode              Deprecated. Use the archlvl command instead
         asn_and_lx_reuse      Command deprecated. Use facility command instead
         attach               *Configure device
         auto_scsi_mount      *Command deprecated - Use "SCSIMOUNT"
         autoinit             *Display/Set auto-create-empty-tape-file option
         automount            *Display/Update allowable tape automount directories
         b                    *Set breakpoint
         b+                    (Synonym for 'b')
         b-                    Delete breakpoint
         b?                    Query breakpoint
         cachestats            Cache stats command
         cckd                 *Compressed CKD command
         cctape               *Display a printer's current cctape
         cf                   *Configure current CPU online or offline
         cfall                 Configure all CPU's online or offline
         clocks                Display tod clkc and cpu timer
         cmdlvl               *Display/Set current command group
         cmdsep               *Display/Set command line separator
         cmpscpad             *Set/display the CMPSC zero padding value.
         cnslport              Set console port
         codepage             *Set/display code page conversion table
         conkpalv             *Display/alter console TCP keepalive settings
         cp_updt              *Create/Modify user character conversion table
         cpu                  *Define target cpu for panel display and commands
         cpuidfmt              Set format BASIC/0/1 STIDP generation
         cpumodel              Set CPU model number
         cpuprio              *(deprecated)
         cpuserial             Set CPU serial number
         cpuverid             *Set CPU version number
         cr                   *Display or alter control registers
         cscript              *Cancels a running script thread
         ctc                  *Enable/Disable CTC debugging
         define               *Rename device
         defsym               *Define symbol
         delsym               *Delete a symbol
         detach               *Remove device
         devinit              *Reinitialize device
         devlist              *List device, device class, or all devices
         devprio              *(deprecated)
         devtmax              *Display or set max device threads
         diag8cmd             *Set DIAG 8 instruction options
         ds                    Display subchannel
         dumpdev              *Specify bootstrap loader DUMP parameters
         ecps:vm              *Command deprecated - Use "ECPSVM"
         ecpsvm               *ECPS:VM Commands
         engines               Set engines parameter
         evm                  *Command deprecated - Use "ECPSVM"
         exec                 *Execute a Rexx script
         exit                  (Synonym for 'quit')
         ext                   Generate external interrupt
         f?                    Query unusable page frame range(s)
         facility             *Enable/Disable/Query z/Arch STFLE Facility bits
         fcb                  *Display a printer's current FCB
         fpc                  *Display or alter floating point control register
         fpr                  *Display or alter floating point registers
         f{+/-}adr            *Mark page frame(s) as +usable/-unusable
         g                     Turn off instruction stepping and start all CPUs
         gpr                  *Display or alter general purpose registers
         hao                  *Hercules Automatic Operator
         help                 *list all commands / command specific help
         herclogo             *Read a new hercules logo file
         hercnice             *(deprecated)
         hercprio             *(deprecated)
         hst                  *History of commands
         http                 *Start/Stop/Modify/Display HTTP Server
         hwldr                *Specify boot loader filename
         i                     Generate I/O attention interrupt for device
         iodelay              *Display or set I/O delay value
         ipending              Display pending interrupts
         ipl                  *IPL from device or file
         iplc                 *Command deprecated - use IPL with clear option
         k                     Display cckd internal trace
         ldmod                *Load a module
         legacysenseid         Set legacysenseid setting
         loadcore             *Load a core image file
         loaddev              *Specify bootstrap loader IPL parameters
         loadparm             *Set the default IPL 'LOADPARM' parameter
         loadtext             *Load a text deck file
         locks                *Display internal locks list
         log                  *Direct logger output
         logopt               *Set/Display logging options
         lparname             *Set LPAR name
         lparnum              *Set LPAR identification number
         lsdep                 List module dependencies
         lsequ                 List device equates
         lsmod                *List dynamic modules
         mainsize             *Define/Display mainsize parameter
         manufacturer          Set STSI manufacturer code
         maxcpu                Set maxcpu parameter
         maxrates             *Display highest MIPS/SIOS rate or set interval
         message              *Display message on console a la VM
         model                *Set/Query STSI model code
         modpath              *Set module load path
         mounted_tape_reinit  *Control tape initialization
         msg                   Alias for message
         msglevel             *Display/Set current Message Display output
         msglvl                Alias for msglevel
         msgnoh                Similar to "message" but no header
         mt                   *Control magnetic tape operation
         netdev               *Set default host networking device
         numcpu                Set numcpu parameter
         osa                  *(Synonym for 'qeth')
         ostailor             *Tailor trace information for specific OS
         o{+/-}dev             Turn ORB tracing on/off
         panopt               *Set or display panel options
         panrate               (deprecated; use PANOPT RATE=nnn instead)
         pantitle              (deprecated; use PANOPT TITLE=xxx instead)
         pgmprdos             *Set LPP license setting
         pgmtrace             *Trace program interrupts
         plant                 Set STSI plant code
         pr                   *Display or alter prefix register
         psw                  *Display or alter program status word
         ptp                  *Enable/Disable PTP debugging
         ptt                  *Activate or display internal trace table
         qcpuid               *Display cpuid(s)
         qd                   *Query device information
         qeth                 *Enable/Disable QETH debugging
         qpfkeys               Display the current PF Key settings
         qpid                  Display Process ID of Hercules
         qports                Display TCP/IP ports in use
         qproc                 Display processors type and utilization
         qstor                 Display main and expanded storage values
         quiet                *Toggle automatic refresh of panel display data
         quit                 *Terminate the emulator
         r                    *Display or alter real storage
         restart               Generate restart interrupt
         resume                Resume hercules
         rexx                 *Modify/Display Hercules's Rexx settings
         rmmod                 Delete a module
         s                    *Instruction stepping
         s+                   *Activate instruction stepping
         s-                    Turn off instruction stepping
         s?                   *Query instruction stepping
         savecore             *Save a core image to file
         sclproot             *Set SCLP base directory
         scpecho              *Set/Display option to echo to console and history of scp replies
         scpimply             *Set/Display option to pass non-hercules commands to the scp
         script               *Run a sequence of panel commands contained in a file
         scsimount            *Automatic SCSI tape mounts
         sf+dev               *Add shadow file
         sf-dev               *Delete shadow file
         sfc                  *Compress shadow files
         sfd                  *Display shadow file stats
         sfk                  *Check shadow files
         sh                   *Shell command
         shcmdopt             *Set shell command options
         shrd                 *shrd command
         shrdport             *Set shrdport value
         sizeof                Display size of structures
         srvprio              *(deprecated)
         ssd                  *Signal shutdown
         start                *Start CPU (or printer/punch device if argument given)
         startall              Start all CPU's
         stop                 *Stop CPU (or printer/punch device if argument given)
         stopall               Stop all CPU's
         store                 Store CPU status at absolute zero
         suspend               Suspend hercules
         symptom               Alias for traceopt
         sysclear             *System Clear Reset manual operation
         sysepoch              Set sysepoch parameter
         sysreset             *System Reset manual operation
         s{+/-}dev             Turn CCW stepping on/off
         t                    *Set tracing range or Query tracing
         t+                   *Turn on instruction tracing
         t+-                  *Automatic instruction tracing
         t-                    Turn off instruction tracing
         t?                   *Query instruction tracing values
         threads              *Display internal threads list
         timerint             *Display or set timers update interval
         tlb                   Display TLB tables
         toddrag               Display or set TOD clock drag factor
         todprio              *(deprecated)
         traceopt             *Instruction and/or CCW trace display option
         tt32                 *Control/query CTCI-WIN functionality
         txf                  *Transactional-Execution Facility tracing
         tzoffset              Set tzoffset parameter
         t{+/-}CKD [devnum]    Turn CKD Search Key tracing on/off
         t{+/-}dev             Turn CCW tracing on/off
         u                    *Disassemble storage
         uptime                Display how long Hercules has been running
         v                    *Display or alter virtual storage
         version               Display version information
         xpndsize             *Define/Display xpndsize parameter
         yroffset              Set yroffset parameter

          (*)  Enter "help <command>" for more info.

The ipl command may also be used to perform a load from cdrom or server. For example if a standard SuSE S/390 Linux distribution CD is loaded and mounted on /cdrom for example, this cdrom may then be ipl-ed by: `ipl /cdrom/suse.ins`

The attach and detach commands are used to dynamically add or remove devices from the configuration, and the define command can be used to alter the device number of an existing device.

The devinit command can be used to reopen an existing device. The args (if specified) override the arguments specified in the configuration file for this device. The device type cannot be changed and must not be specified. This command can be used to rewind a tape, to mount a new tape or disk image file on an existing device, to load a new card deck into a reader, or to close and reopen a printer or punch device.

In single-step mode, pressing the enter key will advance to the next instruction.

There is also an alternate semi-graphical control panel. Press Esc to switch between the command line format and the semi-graphical format. Press ? to obtain help in either control panel.

When a command is prefixed with `'-'` (minus sign or dash), then the command will not be redisplayed at the console. This can be used in scripts and is also used internally when commands are to be invoked without being redisplayed at the panel.
Additional Command Help
Some commands also offer additional help information regarding their syntax, etc. Enter "`help <command name>`" to display this additional help information. (Note: not every command supports additional help)

#### The hercules.rc (run-commands) file

Hercules also supports the ability to automatically execute panel commands upon startup via the 'run-commands' file. If the run-commands file is found to exist when Hercules starts, each line contained within it is read and interpreted as a panel command exactly as if the command were entered from the HMC system console.

The default filename for the run-commands file is "hercules.rc", but may be overridden by setting the "`HERCULES_RC`" environment variable to the desired filename.

Except for the 'pause' command (see paragraph further below), each command read from the run-commands file is logged to the console preceded by a '> ' (greater-than sign) character so you can easily distinguish between panel commands entered from the keyboard from those entered via the .rc file.

Lines starting with '`#`' (pound or hash) are treated as "silent comments" and are thus not logged to the console. Line starting with '`*`' (asterisk) however are treated as "loud comments" and will be logged.

In addition to being able to execute any valid panel command (including the `'sh'` shell command) via the run-commands file, an additional '`pause nnn`' command is supported in order to introduce a brief delay before reading and processing the next line in the file. The value `nnn` can be any number from 0.001 to 999.0 and specifies the number of seconds to delay before reading the next line. Creative use of the run-commands file can completely automate Hercules startup.

#### The "Hercules Automatic Operator" (HAO) Facility

The Hercules Automatic Operator (HAO) feature is a facility which can automatically issue panel commands in response to specific messages appearing on the Hercules console.

To use the Hercules Automatic Operator facility, you first define a "rule" consisting of a "target" and an associated "command". The "target" is a regular expression pattern used to match against the text of the various messages that Hercules issues as it runs. Whenever a match is found, the rule "fires" (is triggered) and its associated command is automatically issued.

The Hercules Automatic Operator facility only operates on messages issued to the Hercules console. These messages may originate from Hercules itself, or from the guest operating system via the SCP SYSCONS interface or via the integrated console printer-keyboard (3215-C or 1052-C). HAO cannot intercept messages issued by the guest operating system to its own 3270 terminals.

##### Defining a Rule

To define a HAO rule, enter the command:

       hao tgt target

to define the rule's "target" match pattern, followed by a second command:

       hao cmd command

to define that rule's associated panel-command.

The target is a regular expression as defined by your host platform. When running on Linux, Hercules uses POSIX Extended Regular Expression syntax. On a Windows platform, regular expression support is provided by Perl Compatible Regular Expression (PCRE). The HAO facility can only be used if regular expression support was included in Hercules at build time.

The associated command is whatever valid Hercules panel command you wish to issue in response to a message being issued that matches the given target pattern.

##### Substituting substrings in the command

The command may contain special variables $1, $2, etc, which will be replaced by the values of "capturing groups" in the match pattern. A capturing group is a part of the regular expression enclosed in parentheses which is matched with text in the target message. In this way, commands may be constructed which contain substrings extracted from the message which triggered the command.

The following special variables are recognized:

- `$1` to `$9` - the text which matched the 1st to 9th capturing group in the target regular expression
- `$`` - the text preceding the regular expression match
- `$'` - the text following the regular expression match
- `$$` - replaced by a single dollar sign

Note that substitution of a $n variable does not occur if there are fewer than n capturing groups in the regular expression.

As an example, the rule below issues the command "`i 001F`" in response to the Hercules message "`HHC01090I 0:001F COMM: client 127.0.0.1 devtype 3270: connection reset`":

       hao tgt HHC01090I .:([0-9A-F]{4}) COMM: .* connection reset
       hao cmd i $1

Another example, shown below, illustrates how the dot matrix display of a 3590(?) tape unit might be used to implement an automatic tape library in response to the Hercules message "`HHC00224I 0:0581 Tape file *, type HET: display "K2DSBK2 " / "M2DSBK3S" (alternating)`":

       hao tgt HHC00224I .:([0-9A-F]{4}) Tape file .*: display (?:".{8}" \/ )?"M([A-Z0-9]{1,6})\s*S"
       hao cmd devinit $1 /u/tapes/$2.aws

Which would result in the Hercules command "`devinit 0581 /u/tapes/2DSBK3.aws`" being automatically issued.

More information about Perl Compatible Regular Expression (PCRE) syntax (as well as a nice online web page that allows you to test your expressions) can be found here:

- PCRE Regex Cheatsheet
- Online PCRE test page

##### Other commands and limitations

To delete a fully or partially defined HAO rule, first use the "`hao list`" command to list all of the defined (or partially defined) rules, and then use the "`hao del nnn`" command to delete the specific rule identified by nnn (all rules are assigned numbers as they are defined and are thus identified by their numeric value). Optionally, you can delete all defined or partially defined rules by issuing the command "`hao clear`".

The current implementation limits the total number of defined rules to 64. This limit may be raised by increasing the value of the `HAO_MAXRULE` constant in source file `hao.c` and then rebuilding Hercules.

All defined rules are checked for a match each time Hercules issues a message. There is no way to specify "stop processing subsequent rules". If a message is issued that matches two or more rules, each associated command is then issued in sequence.

## Technical Support

For technical support, please see our Technical Support web page.