A.When the shell establishes the redirection it overwrites the target file before the redirected command starts and opens itfor reading.

B.Redirection for shell commands do not work using the > character. It only works using the | character instead.

C.The command sed did not match anything in that file therefore the output is empty.

D.The file order is incorrect. The destination file must be mentioned before the command to ensure redirection.

A.yum list-update

B.dpkg list

C.yum check-update

D.yum list

E.dpkg check-update

A.filea.txtis owned by another user and a regular user cannot change the permissions of another user's file.

B.filea.txtis a symbolic link whose permissions are a fixed value which cannot be charged.

C.filea.txthas the sticky bit set and a regular user cannot remove this permission.

D.filea.txtis a hard link whose permissions are inherited from the target and cannot be set directly.

E.filea.txthas the SetUID bit set which imposes the restriction that only the rootuser can make changes to the file.

A.quota -e

B.edquota

C.quota

D.repquota

A.nomesg

B.silent

C.quiet

D.verbose=0