在Linux下，使用

gets(cmd)

函数报错：warning: the 'gets' function is dangerous and should not be used.

解决办法：采用

fgets(cmd,100,stdin);//100为size

问题解决！

fgets从stdin中读字符，直至读到换行符或文件结束，但一次最多读size个字符。读出的字符连同换行符存入缓冲区cmd中。返回指向cmd的指针。

gets把从stdin中输入的一行信息存入cmd中，然后将换行符置换成串结尾符NULL。用户要保证缓冲区的长度大于或等于最大的行长。

gets的详细解释：

char * gets ( char * str );//Get string from stdin

Reads characters from stdin and stores them as a string into str  until a newline character ('\n') or the End-of-File is reached.
The ending newline character ('\n') is not included in the string.

A null character ('\0') is automatically appended after the last character copied