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树莓派2,开发nginx + php + sqlite,现在php和C语言的程序都写好了,C程序写的是串口通信,但是用exec调用返回是空,但是如果调用helloworld却可以调用,请问这是为什么?


回复讨论(解决方案)

php 的 exec 接受的是外部程序的标准输出

那应该用什么调用呢,system,exec,passthru都不行,本人初写,求教

关键是你的 c 程序是如何向 php 返回数据的

关键是你的 c 程序是如何向 php 返回数据的


我C程序是串口发指定信息,返回信息写入sqlite的数据库,然后php查询数据库

问题知道了,是php调用C程序时,串口打开失败,但单独运行C程序是可以的,不知道为什么

那exec调用返回是不是空有什么关系?
你查表得数据不就行了?

那exec调用返回是不是空有什么关系?
你查表得数据不就行了?


现在是串口不能open,nFd = open("/dev/ttyAMA0", O_RDWR|O_NOCTTY);这个返回-1,。

你那是 c 的问题,不是 php 的问题
你得去 c/c++ 找专家

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