The ACS directory structure is very straightforward, but it may not be very intuitive to newcomers. There are a couple of concepts that we need to consider:

MODROOT_WS and MODROOT_LCU, MODROOT_WS_LCU
ACSROOT
ACSDATA
INTROOT and INTLIST

MODROOT

All three variants of MODROOT represent a very similar scenario. They create a module directory, either for WorkStation (MODROOT_WS), for Local Control Unit (LCU) (MODROOT_LCU) or for both (MODROOT_WS_LCU). Executing each bears a similar structure:

MODROOT_WS

getTemplateForDirectory MODROOT_WS wsModule

acs almamgr:~ 30449 > tree wsModule/
wsModule/
├── bin
├── ChangeLog
├── config
│   └── CDB
│       └── schemas
├── doc
├── idl
├── include
├── lib
│   ├── ACScomponents
│   ├── endorsed
│   └── python
│       └── site-packages
├── LOGS
├── man
│   ├── man1
│   ├── man2
│   ├── man3
│   ├── man4
│   ├── man5
│   ├── man6
│   ├── man7
│   ├── man8
│   ├── manl
│   └── mann
├── object
├── rtai
├── src
│   └── Makefile
└── test

MODROOT_LCU

getTemplateForDirectory MODROOT_WS lcuModule

acs almamgr:~ 30451 > tree lcuModule
lcuModule
├── bin
├── ChangeLog
├── doc
├── idl
├── include
├── lib
│   ├── ACScomponents
│   ├── endorsed
│   └── python
│       └── site-packages
├── LOGS
├── man
│   ├── man1
│   ├── man2
│   ├── man3
│   ├── man4
│   ├── man5
│   ├── man6
│   ├── man7
│   ├── man8
│   ├── manl
│   └── mann
├── object
├── src
│   └── Makefile
└── test

MODROOT_WS_LCU

getTemplateForDirectory MODROOT_WS_LCU module

acs almamgr:~ 30459 > tree module
module/
├── ChangeLog
├── lcu
│   ├── bin
│   ├── doc
│   ├── idl
│   ├── include
│   ├── lib
│   │   ├── ACScomponents
│   │   ├── endorsed
│   │   └── python
│   │       └── site-packages
│   ├── LOGS
│   ├── man
│   │   ├── man1
│   │   ├── man2
│   │   ├── man3
│   │   ├── man4
│   │   ├── man5
│   │   ├── man6
│   │   ├── man7
│   │   ├── man8
│   │   ├── manl
│   │   └── mann
│   ├── object
│   ├── src
│   │   └── Makefile
│   └── test
└── ws
    ├── bin
    ├── config
    │   └── CDB
    │       └── schemas
    ├── doc
    ├── idl
    ├── include
    ├── lib
    │   ├── ACScomponents
    │   ├── endorsed
    │   └── python
    │       └── site-packages
    ├── LOGS
    ├── man
    │   ├── man1
    │   ├── man2
    │   ├── man3
    │   ├── man4
    │   ├── man5
    │   ├── man6
    │   ├── man7
    │   ├── man8
    │   ├── manl
    │   └── mann
    ├── object
    ├── src
    │   └── Makefile
    └── test

Files and Directory Description

As we can see, there are several files and directories created under each of the scenarios:

bin: Here we place the scripts and binaries that get executed. This could be added to PATH environment variable
Changelog: A file that could be used to register changes of the module. We make use of JIRA and "git log" for this, but this could be used as an additional place for this information.
config: Directory for configurations.
- config/CDB: Directory for module's CDB configurations. Could be used with ACS_CDB environment variable to configure a CDB for testing the module
  - config/CDB/schemas: The XML Schema (XSD) files are placed in this directory
doc: Directory to place documentation
idl: Directory for IDL (.idl, .midl) files, XML error definitions, XML Schema binding file, etc.
include: Directory for C++ headers, inline and template files
lib: Directory for C++ libraries and Java JAR files. Could be used in LD_LIBRARY_PATH (C++ libraries) and in CLASSPATH (Jar files) to make use of the module's libraries and jar files
- lib/ACSComponents: Directory for Java JAR files associated with components
- lib/endorsed: Directory for endorsed JAR files (No longer relevant since Java 11 disabled the use of endorsed JARs)
- lib/python: Directory for Python code
  - lib/python/site-packages: Python site-packages are placed here. Could be used with PYTHONPATH environment variable to make use of the Python code and cached code (.pyc)
LOGS: Directory where logs can be placed
man: Man documentation in Unix/Linux style could be placed here. See more at https://linux.die.net/man/ page.
- man/man<n>: Look at the link above
- man/manl: Look at the link above
- man/mann: Look at the link above
object: Directory for temporary files such as C++ compiled objects, code-generated source files, etc.
rtai: Directory for Real Time Application Interface (RTAI) and other compiled kernel modules to be installed
src: Directory for source files
- src/Makefile: The main file to define the targets to be compiled, installed and deployed by the moduled
test: Directory that contains all the necessary files for testing. Source code, Makefile, TAT configuration files, reference files, etc.

ACSROOT

The ACSROOT directory is considered an "installation area". When you compile a module and call "make install", ACSROOT is the default destination area for ACS modules' installation.

acs almamgr:~ 31443 > getTemplateForDirectory ACSROOT acs.root

acs almamgr:~ 31445 > tree acs.root/
acs.root/
├── ALARMS
│   └── HELP
├── app-defaults
├── bin
├── bitmaps
├── CDT
├── config
│   └── CDB
│       └── schemas
├── ERRORS
│   └── HELP
├── idl
├── include
├── lib
│   ├── ACScomponents
│   ├── endorsed
│   └── python
│       └── site-packages
├── LOGS
├── man
│   ├── man1
│   ├── man2
│   ├── man3
│   ├── man4
│   ├── man5
│   ├── man6
│   ├── man7
│   ├── man8
│   ├── manl
│   └── mann
├── rtai
├── sounds
├── templates
└── vw
    ├── bin
    │   ├── MC68000
    │   ├── MC68040
    │   └── PPC604
    ├── CIT
    ├── idl
    ├── include
    ├── lib
    │   ├── ACScomponents
    │   ├── endorsed
    │   ├── MC68000
    │   ├── MC68040
    │   ├── PPC604
    │   └── python
    │       └── site-packages
    └── man
        ├── man1
        ├── man2
        ├── man3
        ├── man4
        ├── man5
        ├── man6
        ├── man7
        ├── man8
        ├── manl
        └── mann

60 directories, 0 files

The directory structure is very similar to MODROOT, bin, config, idl, include, lib, LOGS, man and rtai are equivalent for the MODROOT definitions, although only the targets selected for installation are finally placed there. Changelog, src, doc, object and test are not found in the installation areas. Other directories are as follows:

ALARMS and ALARMS/HELP: Alarm definition documentation (Not used)
app-defaults: Not used.
bitmaps: Not used.
CDT: Not used.
ERRORS and ERRORS/HELP: Error definition documentation (Not used)
sounds: Not used
templates: Templates, such as the ones used for getTemplateForDirectory command are placed here
vw: VxWorks. Not used in most projects. Used at APEX observatory.

ACSDATA

ACSDATA is a place associated with runtime configurations and output of data.

getTemplateForDirectory ACSDATA acs.data

acs almamgr:~ 30451 > tree acs.data
acs.data
├── config
├── dumps
├── ENVIRONMENTS
├── logs
└── tmp

5 directories, 0 files

Files and Directory Description

config: Configuration files, including CDB, schemas and other files
dumps: Core dumps, heap dumps, etc. can be placed in this directory
ENVIRONMENTS: Not used
logs: Runtime logs can be placed in this directory
tmp: Runtime temporary data is placed here

INTROOT/INTLIST

INTROOT is an installation area with the same structure as ACSROOT, but the main difference is that it allows to install code without interfering with the ACS (or your project installation). It is very handy for development and experimental tests and also as a patching system, specially when used in combination with INTLIST. INTLIST is just a list of INTROOTs, which have an order of prioritization which will be used to choose binaries, libraries, jars, python code, etc. from one place or another. Everything that is in two or more INTROOTs gets hidden for the lower priority one by the one with highest priority.

INTROOT

getTemplateForDirectory INTROOT introot

acs almamgr:~ 30463 > tree introot
introot
├── ALARMS
│   └── HELP
├── app-defaults
├── bin
├── bitmaps
├── CDT
├── config
│   └── CDB
│       └── schemas
├── ERRORS
│   └── HELP
├── idl
├── include
├── lib
│   ├── ACScomponents
│   ├── endorsed
│   └── python
│       └── site-packages
├── LOGS
├── man
│   ├── man1
│   ├── man2
│   ├── man3
│   ├── man4
│   ├── man5
│   ├── man6
│   ├── man7
│   ├── man8
│   ├── manl
│   └── mann
├── responsible
├── rtai
├── sounds
├── Sources
├── templates
└── vw
    ├── bin
    │   ├── MC68000
    │   ├── MC68040
    │   └── PPC604
    ├── CIT
    ├── idl
    ├── include
    ├── lib
    │   ├── ACScomponents
    │   ├── endorsed
    │   ├── MC68000
    │   ├── MC68040
    │   ├── PPC604
    │   └── python
    │       └── site-packages
    ├── man
    │   ├── man1
    │   ├── man2
    │   ├── man3
    │   ├── man4
    │   ├── man5
    │   ├── man6
    │   ├── man7
    │   ├── man8
    │   ├── manl
    │   └── mann
    └── Sources

62 directories, 1 file

The same directory structure as ACSROOT is present. Here you see one more:

Sources: Here, a copy of src/include directories get installed along with your build, allowing you to analyze exact pieces of code used to produce the build. This directory is also installed to ACSROOT, but the getTemplateForDirectory is actually ignoring the creation of the Sources directory.

INTLIST

The INTLIST is just an environment variable used by the ACS .bash_profile.acs script to configure several INTROOTs in an order of priority.

export INTLIST=~/introot1:~/introot2:~/introot3:~/introot4

In the example above, it will have four INTROOTs configured in parallel, where ~/introot1 has the highest priority and ~/introot4 the lowest. This means that every binary or script offered by ~/introot1 will be used first, and things from ~/introot4 will only be used if they're not shadowed by a different version provided in the other 3 INTROOTs.