仅在打印时出现段错误
我有一个循环，看起来像这样
while(condition){
read_some_data(source, buf, BUFSIZE);
printf(buf);
memset(buf, 0, BUFSIZE+1);
//do stuff to affect condition that does not touch buf
}
buf 是一个大小为 BUFSIZE+1 的字符数组。奇怪的是，如果我注释掉 printf，程序就会完美执行，没有分段错误。只有当我尝试打印 buf 时，我才遇到问题。此外，段错误不一定发生在循环的第一次迭代上。通常需要 6 或 7 次迭代。
此外，该程序中没有动态内存分配。
I have a loop that looks something like this
while(condition){
read_some_data(source, buf, BUFSIZE);
printf(buf);
memset(buf, 0, BUFSIZE+1);
//do stuff to affect condition that does not touch buf
}
buf is an char array of size BUFSIZE+1. The strange thing is that if I comment out the printf, the program executes perfectly with no segmentation fault. It is only when I try to print out buf that I get the problem. Also, the seg fault does not necessarily happen on the first iteration of the loop. It usually takes 6 or 7 iterations.
Also, there is no dynamic memory allocation in this program.
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评论（5）
buf在分配范围内的某个位置有一个空（零值）字节。printf可以通过该空字节判断它已到达字符串的末尾；如果没有它，它将继续阅读可以安全地阅读的地方。buf不包含%d等printf可能用来指示其他参数的内容。更好的是，只需使用printf("%s", buf)，即可完全消除任何此类风险。bufhas a null (zero-valued) byte somewhere within the allocated range. That null byte is howprintfcan tell that it's reached the end of a string; without it, it will keep reading past where it can safely do so.bufdoesn't contain anything like%dthatprintfmight take to indicate additional arguments. Better yet — just useprintf("%s", buf), which completely eliminates any such risk.您缺少 printf 的格式说明符参数
You are missing the format specifier argument to printf
确保
buf是以\0结尾的字符串。只有这样
printf()才能打印字符串。Make sure
bufis\0terminated string.Only then
printf()could print the string.您需要将字符串指定为打印参数：
printf("%s", buf);。希望这有帮助！
NS
You need to specify the string as a print parameter:
printf("%s", buf);.Hope this helps!
N.S.
它是以空终止的吗？如果您只想将 buf 写到标准输出，为什么要调用 printf(buf) 而不是 puts(buf) 呢？
Is it null-terminated? And why are you calling printf(buf) rather than puts(buf) if all you want to do is to write out the buf to stdout?