sth about the string function strdup

As now I was using the fundtion strdup very often, so that I want to say sth about it, and I think that it just a function that combines the functions malloc and strcpy.

用法：#include <string.h>

功能：复制字符串s

说明：返回指向被复制的字符串的指针，所需空间由malloc()分配且可以由free()释放。

举例：

// strdup.c

#include <syslib.h>
#include <string.h>

main()
{
char *s="this is just f";
char *d;

d=strdup(s);
printf("%s",d);

getchar();
return 0;
}
strdup()主要是拷贝字符串s的一个副本，由函数返回值返回，这个副本有自己的内存空间，和s不相干。

char *strdup(const char *s)
{
char *t = NULL;
if (s && (t = (char*)malloc(strlen(s) + 1)))
strcpy(t, s);
return t;
}