.TH COPYTAPE 5  "8 August 1986"
.SH NAME
copytape \- copytape intermediate data file format
.SH DESCRIPTION
.I copytape
duplicates magtapes on single\-tape systems by making
an intermediate copy of the tape in a disk file.
This disk file has a special format that preserves
the block boundaries and tape marks of the original
physical tape.
.PP
Each block is preceded by a header identifying what
sort of block it is.  In the case of data blocks,
the length of the data is also given.  Each header is
on a separate text line, followed by a newline character.
.sp
.TP 3
CPTP:BLK \fInnnnnn\fP
.ti -3
\fIdata\fP\\n
.sp
A data block is identified by the keyword
.IR BLK .
The length of the block is given in a six\-character
numeric field.  The field is zero\-padded on the left if
less than six characters are needed.  The header is
followed by a newline character.
The original data follows.  The data may have any characters
in it, since
.I copytape
uses a read(2) to extract it.
The data is followed by a newline, to make the file easy
to view with an editor.
.TP 3
CPTP:MRK
A tape mark was encountered in the original tape.
.TP 3
CPTP:EOT
When two consecutive tape marks are encountered,
.I copytape
treats the second as a logical end\-of\-tape.  On
output, both MRK and EOT generate
a physical tape mark.
.I copytape
stops processing after copying an EOT.
.SH "SEE ALSO"
mtio(4)
.SH BUGS
Some weird tapes may not use two consecutive tape marks
as logical end\-of\-tape.