Recursing into subdirectories

One of the things that needs to be done when backing up files is to determine what files exist on the server. I had written code to recurse into subdirectories, but it was very slow. It also basically only gave the filename, which necessitated a call to stat to get the important information. Then I discovered a system call ftw and nftw. These calls do the work of recursing into the subdirectories, and also provides the stat structure for each file. It is also very much faster than my original code. Here is the code I wrote to do that:

#define _XOPEN_SOURCE 500
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

static int
display_info(const char *fpath, const struct stat *sb,
int tflag, struct FTW *ftwbuf)
{
printf("p:%s ",fpath);
printf("tf:%d ",tflag);
printf("dev:%lu ",sb->st_dev);
printf("ino:%lu ",sb->st_ino);
printf("m:%o ",sb->st_mode);
printf("nl:%lu ",sb->st_nlink);
printf("u:%d ",sb->st_uid);
printf("g:%d ",sb->st_gid);
printf("rd:%lx ",sb->st_rdev);
printf("s:%lu ",sb->st_size);
printf("bs:%lu ",sb->st_blksize);
printf("b:%lu ",sb->st_blocks);
printf("ta:%lu ",sb->st_atime);
printf("tm:%lu ",sb->st_mtime);
printf("tc:%lu ",sb->st_ctime);
printf("\n");
return 0; /* To tell nftw() to continue */
}

int
main(int argc, char *argv[])
{
int flags = FTW_MOUNT;

if (argc > 2 && strchr(argv[2], 'd') != NULL)
flags = FTW_DEPTH;
if (argc > 2 && strchr(argv[2], 'p') != NULL)
flags = FTW_PHYS;

if (nftw64((argc < 2) ? "." : argv[1], display_info, 80, flags) == -1) {
perror("nftw");
exit(EXIT_FAILURE);
}
exit(EXIT_SUCCESS);
}