pointer问题？

[Fallingstar]

#include <stdio.h>
#include <string.h>

#define MAXLINES 5000 /* max #lines to be sorted */
char *lineptr[MAXLINES]; /* pointers to text lines */

int readlines(char *lineptr[], int nlines);
void writelines(char *lineptr[], int nlines);

void qsort(void *lineptr[], int left, int right,
int (*comp)(void *, void *));
int numcmp(char *, char *);

/* sort input lines */
main(int argc, char *argv[])
{
int nlines; /* number of input lines read */
int numeric = 0; /* 1 if numeric sort */

if (argc > 1 && strcmp(argv[1], "-n") == 0)
numeric = 1;
if ((nlines = readlines(lineptr, MAXLINES)) >= 0) {
qsort((void**) lineptr, 0, nlines-1,
(int (*)(void*,void*))(numeric ? numcmp : strcmp));
writelines(lineptr, nlines);
return 0;
} else {
printf("input too big to sort\n");
return 1;
}
}
(void**) lineptr
(int (*)(void*,void*))
怎样解释？

[kwok_1980]

(void**) lineptr//强制转换成二级void类型的指针
(int (*)(void*,void*))//指针函数,函数的返回类型为int,有两个void*的参数

[tinytot]

(void**) lineptr 把lineptr强制转换成一个空指针数组
int (*)(void*,void*))是指向一个返回值为整型,形参为两个空空指针的函数指针.