---
name: "tcopy"
section: "1"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/tcopy"
---

# tcopy(1)

read, write, copy and verify tapes

## NAME

**tcopy** – read, write, copy and verify tapes

## SYNOPSIS

**tcopy** \[**-crvx**\] \[**-l** *logfile*\] \[**-s** *maxblk*\] \[*src* \[*dest*\]\]

## DESCRIPTION

The **tcopy** utility is designed to read, write and copy tapes.

The only assumption made about the tape layout is that there are two sequential EOF marks at the end.

The *src* argument can be a tape device and defaults to */dev/sa0* or it can be data in SIMH-TAP format. If *src* is “**-**” the standard input is read.

If the *dest* argument is also specified, a copy of the *src* will be made onto the *dest*. If *dest* is “**-**” standard output will be written to.

If *dest* is a tape device, the file and record structure will be the same.

If *dest* is a filename ending in “**.000**” the contents each file on *src* will be written to sequentially numbered files “**.000**”, “**.001**”, “**.002**” etc. Information about record sizes will be lost.

If the **-r** flag is specified, only the data will be written, information about file and record layout is lost.

Otherwise the data, file and record structure of *src* will be written in SIMH-TAP format.

The **tcopy** utility will report information about the layout of *src* like this on standard output:

```
file 0: block size 80: 6 records
file 0: eof after 6 records: 480 bytes
file 1: block size 3072: records 0 to 262
file 1: block size 612: record 262
file 1: eof after 263 records: 805476 bytes
[…]
eot
total length: 972851280 bytes time: 41 s rate: 22934.8 kB/s
```

If *dest* is “**-**” or if **-x** is specified this goes to standard error instead, and can also be redirected with **-l** *logfile*, in which case the final total line will also be reported on standard error.

If **tcopy** receives a SIGINFO signal, current counts are reported on standard error.

The following options are available:

- **-c**

  Rewind both tapes, copy *src* to *dest*, rewind again and verify that the two tapes are now identical.

- **-l** *logfile*

  Output all informational messages to *logfile*.

- **-r**

  Write only the contents of all data blocks to the output. The file and record structure of the input will be lost.

- **-s** *maxblk*

  Specify a maximum block size, *maxblk*. The default is *kern.maxphys*.

- **-v**

  Verify that *src* and *dest* are identical. Note that the tapes are not rewound prior to the comparison.

- **-x**

  Output all informational messages to the standard error instead of the standard output. This option is automatic if *dest* is given as “**-**”.

## EXIT STATUS

Unfortunately all over the place, but zero always means succeess.

## EXAMPLES

Verify that the tape in /dev/sa0 can be read and see the layout of its content:

```
tcopy
```

Copy a tape using two tape drives:

```
tcopy  /dev/sa0 /dev/sa1
```

Copy a tape using only a single tape drive, and verify the result:

```
tcopy /dev/sa0 /tmp/temp.tapfile
# change tape
tcopy -c /tmp/temp.tapfile /dev/sa0
```

Make a cryptographic hash of both the contents and the layout of the tape in /dev/sa1:

```
tcopy /dev/sa1 - | sha256
```

Copy a tape to a tape drive on another machine:

```
tcopy /dev/sa0 - | ssh otherhost tcopy - /dev/sa0
```

Extract the tape files into individual files:

```
tcopy /dev/sa0 /tmp/_.tape.000
```

Ignore all structure on the tape and feed all data to [tar(1)](/tar/1.md):

```
tcopy -l /dev/null -r /dev/sa0 - | tar tvf -
```

## SEE ALSO

[mt(1)](/mt/1.md), [mtio(4)](/mtio/4.md), [sa(4)](/sa/4.md)

## STANDARDS

The SIMH-TAP format is documented in the open-simh github repos: *https://github.com/open-simh/simh/blob/master/doc/simh\_magtape.doc*

## HISTORY

The **tcopy** command appeared in 4.3BSD.

## BUGS

-

  Modern tape drives may return a SCSI "Incorrect Length Indicator (ILI)" for each read with a different block size that what is on the tape, and that slows **tcopy** down a lot. This can be disabled with the [mt(1)](/mt/1.md) command:

  ```
  mt param sili -s 1
  ```

-

  End of data (EOD) is determined by two sequential EOF marks with no data between them. There used to be old systems which typically wrote three EOF's between tape files. The **tcopy** utility will erroneously stop copying early in this case.

-

  With **-c** the tape drives are not rewound at the same time, but one after the other.