ltrace.lua pure lua
src/ltrace.c pure C, see src/test.lua, easy to use, but without table dumping, just call ltrace.traceback()
How To Debug With Lua, Lots of print?
We don't need print() any more!
Instead of debug.traceback(), this lib gives you more infomations of every lua call stack frame.
lua Support
luajit Support(with param names for function output)
In C or Java, you just use
try {
// statements
} catch(e) {
// statements
}
while in Lua, you need xpcall like this:
function TryFunc()
-- statement
end
function CatchFunc(err)
-- statement
print(err)
print(debug.traceback())
end
xpcall(TryFunc, CatchFunc)
in CatchFunc, we just call debug.traceback() to get stackframe to locate your mistake.
ltrace.getfulltrace() will show you every variable(name and value) of each frame(with function name, filename and linenum) in lua call stack
Variables show in each frame are sorted by declaration order.
If you are using luajit or lua 5.2 later, param names will be showed in brackets. See Example
frameidx @filepath.lua:linenum in <functionName()>
local_variable_name1:variable_value
local_variable_name2:variable_value
...
local ltrace = require "ltrace"
function errordump(errstr)
io.stderr:write(errstr .. "\n")
end
function main()
-- do call
end
xpcall(main, function(err)
errordump(err)
errordump(ltrace.getfulltrace())
end)
this is a sample of err catching dumping (use luajit or lua 5.2 or later)
test.lua:17: attempt to perform arithmetic on global 'nondefined_var' (a nil value)
0 @test.lua:31 in <__add(err)>
err:"test.lua:17: attempt to perform arithmetic on global 'nondefined_var' (a nil value)"
(*temporary):<file (0x7fff734894a0)>
1 @test.lua:17 in <a(arg1, arg2)>
arg1:"xx"
arg2:"yy"
a000:false
a111:111
a222:"222"
a333:"333"
f:<function: 0x00050568>
t:{[1]=1, [2]=2, [3]=45, [4]=5, [5]=4, [6]=672, ff=<function: 0x000506a0>, s="12", submap={[1]="aa", [2]="bb"}}
(*temporary):"attempt to perform arithmetic on global 'nondefined_var' (a nil value)"
2 @test.lua:24 in <b()>
bt:{[1]=1, [2]=5, [3]=256, [4]="234", a={b="v"}}
bs:"this is a string"
bn:4234239
3 @test.lua:28
4[C] : in <xpcall>
5[C] : in <main>
6[C] : in <C>