If the actual blocking factor is greater than the nominal blocking factor, a read error will result. This function modifier enables tar to work across the Ethernet, since pipes and sockets return partial blocks even when more data is coming. When reading from standard input, '-', this function modifier is selected by default to ensure that tar can recover from short reads. Exit immediately with a positive exit status if any unexpected errors occur. The SYSV3 environment variable overrides the default behavior.
E Write a tarfile with extended headers.
When a tarfile is written with extended headers, the modification time is maintained with a granularity of microseconds rather than seconds. Use the tarfile argument as the name of the tarfile. If the name of the tarfile is '-', tar writes to the standard output or reads from the standard input, whichever is appropriate. With two arguments, FF, tar excludes all directories named SCCS and RCS, all files with .o as their suffix, and all files named errs, core, and a.out. The SYSV3 environment variable overrides the default behavior.