qsort
#define WORDMAX 100

int charcmp(char *x, char *y)
{
return *x - *y;
}

int main()
{
char word[WORDMAX], sig[WORDMAX];
while (scanf( "%s ", word) != EOF)
{
strcpy(sig, word);
qsort(sig, strlen(sig), sizeof(char), charcomp); //这行有什么错？
printf( "%s%s\n ", sig, word);
}
return 0;
}
------------
报错内容：
error: harcomp?undeclared (first use in this function)
error: (Each undeclared identifier is reported only once
error: for each function it appears in.)

[解决办法]
头文件？ <stdlib.h> and <search.h>
[解决办法]
qsort(sig, strlen(sig), sizeof(char), charcomp);

charcomp怎么没有参数?你要算什么...

函数被认为是变量了,自然编译错误.