#include <ftw.h>
int
ftw(directory, funcptr, depth)
char *directory;
int (*funcptr)();
int depth;
#include <sys/stat.h>
int
funcptr(item, sb, flag)
char *item;
struct stat *sb;
int flag;
FTW_F Item is a normal file FTW_D Item is a directory FTW_NS The stat failed on the item FTW_DNR Item is a directory which can't be read
Ftw recursively calls itself when it encounters a directory. To avoid using up all a program's file descriptors, the depth argument specifies the number of simultaneous open directories to maintain. When the depth is exceeded, the routine will become noticeably slower because directories are closed in ``most-recently-used'' order.
To stop the tree walk, the user-supplied function should return a non-zero value; this value will become the return value of ftw. Otherwise, ftw will continue until it has scanned the entire tree, in which case it will return zero, or until it hits an error such as a malloc(3) failure, in which case it will return -1.
Because ftw uses dynamic data structures, the only safe way to exit out of a tree walk is to return a non-zero value. To handle interrupts, for example, mark that the interrupt occured and return a non-zero value--- don't use longjmp (3) unless the program is going to terminate.