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I've added the EPICS Lua support module to our build system. Lua is a scripting language
designed to be embedded, it has a small footprint and is reasonably powerful. It would
provide an alternative to jumping through hoops in st.cmd syntax but also provides a
few other options. All iocsh commands are imported into lua and so you can do things
like:
for index=1,10,1
do
print(string.format("Loading instance: %d", index))
iocsh.dbLoadRecords("test.db", string.format("P=xxx:,Q=%d", index))
end
You execute files from st.cmd using:
epicsEnvSet("LUA_PATH", "${UTILITIES}/lua")
epicsEnvSet("LUA_SCRIPT_PATH","${TOP}/iocBoot/${IOC}")
luash("file.lua")
or just typing luash puts you into an interactive lua shell.
The lua script record is like a calcout record but can execute lua script. It might be an alternative to e.g. aSub records for parsing stream device strings when writing C is a bit overkill.
As well as being able to read/write PVs there is also some asyn integration into lua, so you can read/write/set asyn parameters from lua command line or script record, or even talk to a device by creating an asyn IP port and sending strings. See the documentation directory in lua support module and the example scripts directory in iocBoot
To use
add LUA=$(SUPPORT)/lua/master to configure/RELEASE
add luaSupport.dbd to the IOC Makefile DBD list
add lua and asyn to the IOC Makefile _LIBS list
There are examples of a lua script used in the DETADC, Attocube and OERCONE iocs.
There is a powerpoint about lua here: https://indico.cern.ch/event/766611/contributions/3438291/attachments/1856812/3050126/Lang-Lua_Integrating_Scripting_Language.pdf
See also the documentation on our epics-lua module or the actual epics module for more information on using lua in EPICS.
We are using the style guide from LuaRocks as documented in https://github.com/luarocks/lua-style-guide#conditional-expressions
Go to the luacheck GitHub page and under Windows binary download click the download link which will download the file luacheck.exe
Place the luacheck.exe file in a useful place e.g. Program Files and add that location to your PATH.
Restart any command lines you have open, and then you can run luacheck file.lua against a Lua file.
For more detailed instructions on the use of luacheck see the luacheck documentation