chmod - change mode of satellite file
chmod (path, mode)
points to the path name of a file.
changes the access permissions of the files according to
, and octal number constructed from the OR of the following:
will fail and the file mode will be unchanged if one or more of the
following are true:
The path name specifies a directory or a file that does not
The path name points to a directory, not a file. [EISDIR]
The path name points to a file on the host. [EACCES]
On successful completion, a value of 0 is returned. Otherwise, a
value of -1 is returned and
is set to indicate the error.