Question

我正在尝试使用NodeMCU将string.format原始输出输出到uart。

我正在尝试该功能

uart.write(0,string.format("loop %03d local: %02d | gmt %02d:%02d:%02d local %02d/%02d/%04d\n",loops,timezonetime,gmthours,gmtmins,gmtsecs,Nmonth,Nday,Nyear))

，但\ n被忽略，并且文本被串联。

print(string.format("loop %03d local: %02d | gmt %02d:%02d:%02d local %02d/%02d/%04d",loops,timezonetime,gmthours,gmtmins,gmtsecs,Nmonth,Nday,Nyear))

工作正常，但是我无法控制总是由print（）添加的换行符

如何使用uart.write和string.format来控制输出，包括换行符和其他控制字符的放置和使用？

Answer 1

该问题是由于用于访问NodeMCU板的LuaLoader中换行处理的结果。当与PUTTY一起使用时，输出是预期的。

这是更详细的测试结果。看来\ r在传递给uart.write（）的字符串参数中不起作用

-- uart.write Test
print("______first test____________")   -- prime the output with a line and newline
uart.write(0,"asdfasdfasdfasdfasdf")   -- no newline
print("______should be at end of same line as asdf...______") 
uart.write(0,"asdfasdfasdfasdfasdf(newline)\n")  -- with newline
print("______should be on line following asdf...____________")   
uart.write(0,"asdfasdfasdfasdfasdf(CR)\r")  -- with return only
uart.write(0,"OVERWRITE\n")  -- overwrite the first part of asdf line, then newline
print("______should be on newline below OVERWRITE line ____________")

输出结果：

dofile("uwtest.lua")
______first test____________
asdfasdfasdfasdfasdf______should be at end of same line as asdf...______
asdfasdfasdfasdfasdf(newline)
______should be on line following asdf...____________
asdfasdfasdfasdfasdf(CR)
OVERWRITE
______should be on newline below OVERWRITE line ____________
>

预期结果是字符串“ asdfasdfasdfasdfasdf（CR）\ r”后跟一个CR而不是LF，从而导致终端光标向左移动

这似乎与LuaLoader中的终端仿真有关。

当我用腻子连接到NodeMCU时，得到以下输出：

> dofile("uwtest.lua")
______first test____________
asdfasdfasdfasdfasdf______should be at end of same line as asdf...______
asdfasdfasdfasdfasdf(newline)
                             ______should be on line following asdf...____________
OVERWRITEsdfasdfasdf(CR)
         ______should be on newline below OVERWRITE line ____________
>

腻子输出符合预期。

Lua string.format和换行符或控制字符的使用

1 个答案: