Differences between snprintf Linux and Windows

 

One portProgramDuring the test phase, we found that some characters were lost in Linux,

Find the cause and find that _ snprintf in Windows is different from snprintf in Linux.

 

 

In Linux, sprintf automatically adds '/0' to the end, and the copy length also includes'/0 ';

 

Snprintf man has the following explanations:

 

The functions snprintf () and vsnprintf () do not write more than size bytes (including
Trailing '/0 ').

 

However, in windows, _ snprintf does not follow this rule, that is, simply copy specifies the length of characters, without automatically adding 0, and the length does not contain 0.

 

TestCodeAs follows:

 

 

# Include <stdio. h>

# Include <string. h>

 

Int main ()
{
Char Buf [20];
Char * pstr = "this is a test string ";

Memset (BUF, 0, sizeof (BUF ));

_ Snprintf (BUF, sizeof (BUF)-1, "% s", pstr );

Printf ("Buf = % s, strlen (BUF) = % d/N", Buf, strlen (BUF ));

Return 0;

}

 

In Windows, the result is:

Buf = This is a test stri, strlen (BUF) = 19

 

 

In Linux, the result is: (_ snprintf is replaced with snprintf)

Buf = This is a test STR, strlen (BUF) = 18

 

 

The subtle differences in functions between platforms will inevitably lead to problems ....