readlink(2) -- Linux man page
NAMEreadlink - read value of a symbolic link
DESCRIPTIONreadlink places the contents of the symbolic link path in the buffer buf, which has size bufsiz. readlink does not append a NUL character to buf. It will truncate the contents (to a length of bufsiz characters), in case the buffer is too small to hold all of the contents.
RETURN VALUEThe call returns the count of characters placed in the buffer if it succeeds, or a -1 if an error occurs, placing the error code in errno.
- A component of the path prefix is not a directory.
- bufsiz is not positive.
- A pathname, or a component of a pathname, was too long.
- The named file does not exist.
- Search permission is denied for a component of the path prefix.
- Too many symbolic links were encountered in translating the pathname.
- The named file is not a symbolic link.
- An I/O error occurred while reading from the file system.
- buf extends outside the process's allocated address space.
- Insufficient kernel memory was available.
CONFORMING TOX/OPEN, 4.4BSD (the readlink function call appeared in 4.2BSD).
SEE ALSOstat(2), lstat(2), symlink(2)