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    Length: 2217 (0x8a9)
    Types: TextFile
    Notes: UNIX file
    Names: »bcp.n«

└─⟦26887b7e0⟧ Bits:30009717 Comet 32 harddisk image
    └─⟦28c352965⟧ »/a« UNIX Filesystem
        └─⟦this⟧ »usr/man/mann/bcp.n« 

TextFile

.TH BCP N
.UC 4
.SH NAME
bcp \- buffered copy
.SH SYNOPSIS
.B bcp
[
.BR \-s n
] [
.BR \-i n
] [
.BR \-o n
] [
.BR \-b n
] [ file1  [ file2 ] ]
.SH DESCRIPTION
.I Bcp
copies
.I file1
to
.I file2.
It is mainly used for copying files to and from the raw floppy device
.I /dev/rflop.
It can also be used for ordinary files and for the raw tape device
.I /dev/rmt.
The ordinary copy program
.IR cp (1)
cannot be used since IO must be in multiples of page size (512 bytes)
and there's no way to specify size when copying from a diskette.
.LP
The options are as follows:
.TP 8 
.BR \-s n
The number
.I n
gives the maximum number of pages to copy.
.TP 8
.BR \-i n
Specifies seek offset on input file in multiples of page size.
.TP 8
.BR \-o n
Specifies seek offset on output file in multiples of page size.
.TP 8
.BR \-b n
Gives number of pages to use for internal buffering.
The default is 12 (suitable for keeping a floppy drive busy).
.LP
If a writable ordinary output file exists, it is not truncated but
is merely overwritten at the given offset.
If the output file does not exist, it is created with mode 644.
If an argument file
is not given, or is the string "-", standard input or output
is assumed.
A seek is not possible in this case.
The number of bytes written is rounded up to a multiple of page size
and the remaining bytes are zeroed.
This normally happens when the input file is an ordinary file or a pipe.
.SH EXAMPLES
.nf

bcp -s1600 /dev/rflop flopdump
bcp -s100 -i1500 /dev/rflop floptail
cat foo bar baz | bcp -o1000 - /dev/rflop
bcp -s34000 -b128 /dev/rdc1g /dev/rmt

.fi
The last example shows how to dump an entire disk partition on tape.
The buffer size 128 is the maximum size of raw IO 
used internally by the kernel and is therefore fastest for a streamer
tape that has to backspace between every write.
.LP
A more sophisticated program
.IR dbcopy (N)
that uses 2 synchronized processes is also available.
It is about 20% faster (real, not cpu time) than
.I bcp
for writing an entire diskette.
With present hardware there's no advantage in using it
for tape.
A more general utility for copying and converting
raw files is
.IR dd (1).
.SH SEE ALSO
cp(1), dbcopy(N), dd(1), far(1), tar(1), dump(8)