Alternatively, the file simply might not exist, or the user has mistyped its name. More frequent on command line interfaces than on graphical user interfaces where files are presented iconically and users do not type file names. Check the file name and path name for correctness and try again. If the specified file or directory is a symbolic link, it probably points to a nonexistent file or directory. The symbolic name for this error is ENOENT, errno=2.
Now, any path from s to v' in G' corresponds to an odd-length path from s to v in G. Run either BFS or DFS to determine the vertices reachable from s. Find a topological order of a DAG that cannot be computed as the reverse postorder of a DFS, no matter in which order the DFS chooses starting vertices in the constructor.
The access() returns success when the file is local, but for a remote file access() returns failure." The ult_file.fopen fails when it attempts to read a remote file with ORA-29283, because it is using the access() routine, and "and it fails when appending to a remote file because it creates a brand new file even if the file specified exists "