获取符号链接的真实路径

Question

Suppose that I want to get the real path of a symlink. I know that both readlink and stat system calls can dereference the link and give me its real path. Do they operate in the same way (only regarding the dereferencing, I know that stat does lots more)? Should I prefer one over the other?

Answer 1

Use stat() to tell you about the file at the end of any chain of symlinks; it does not get you the path in any way. Use lstat() to get information about the symlink, if any, that is referred to; it acts like stat() when the name given is not a symlink. Use readlink() to obtain the path name stored in the symlink named as its argument (beware — it does not null terminate the string).

If you want the full pathname of the file at the end of the symlink, you can use realpath() . This gives you an absolute pathname which does not cross any symlinks to reach the file.

Answer 2

Yeah, you should use readlink() for that. However, notice that it requires that you allocate a buffer to store the dereferenced path in. lstat() can help if you want to allocate a buffer of the exact size that is required, as is shown in the example at the bottom of the readlink() man page .