如何确定generice记录器功能的char *的长度？

i am writing a reusable logging module for a firmware prototype. I have a logger api which has a wrapper function void LogWithNum(eLogSubSystem sys, eLogLevel level, char * msg, int * number)

我正在为固件原型编写可重用的日志记录模块。我有一个记录器api,它有一个包装函数void LogWithNum(eLogSubSystem sys,eLogLevel level,char * msg,int * number)

In this wrapper function, a system specific write function is called. Could be UART for example, or a display driver...

在此包装函数中,将调用特定于系统的写入函数。可以是UART,例如显示驱动程序......

All system write / transmit functions somehow require the length in bytes of a message though. And my wrapper function only gets a a char * to the message it should send. See here for example, where my wrapper calls the systems UART transmit function:

所有系统写入/发送功能都以某种方式需要消息的字节长度。而我的包装函数只获取它应该发送的消息的char *。例如,请参阅此处,我的包装器调用系统UART传输功能:

void LogWithNum(eLogSubSystem sys, eLogLevel level, char * msg, int * number)
{

     UARTDRV_Transmit(handle, char * msg, int msglen);
}

How can i derive the length of any message so i can pass it properly to the underlying transmitting function?

我如何得出任何消息的长度,以便我可以将其正确传递给底层传输函数?

I dont want to use large librarys since i am on a uC and want to save space.

我不想使用大型图书馆,因为我在uC上并希望节省空间。

1 个解决方案

#1

Different ways to solve your problem:

解决问题的不同方法:

Using strlen to calculate the c-string length

使用strlen计算c-string长度

void LogWithNum(eLogSubSystem sys, eLogLevel level, char * msg, int * number)
{
     UARTDRV_Transmit(handle, msg, strlen(msg));
}

Or looping through the c-string until null terminator

或者循环遍历c-string,直到null终止符

void LogWithNum(eLogSubSystem sys, eLogLevel level, char * msg, int * number)
{
     while (*msg != '\0')
        UARTDRV_Transmit(handle, msg++, 1);
}

Or calculate the msg length without strlen combining solutions above

或者计算msg长度而不使用上面的strlen组合解决方案

void LogWithNum(eLogSubSystem sys, eLogLevel level, char * msg, int * number)
{
     int msg_length = 0;

     while (*msg++ != '\0')
        msg_length++;

     if (msg_length > 0)
        UARTDRV_Transmit(handle, msg, msg_length);
}

#1