Control your magnetic tapes

Today I made a typo in the shell: instead of m trc (m being my alias for less and trc the name of some trace file), I accidentally typed mt rc. To my surprise, the system didn’t respond with zsh: command not found: mt. It responded with this message:

mt: invalid argument ‘rc’ for ‘operation’
Valid arguments are:
  - ‘eof’, ‘weof’
  - ‘fsf’
  - ‘bsf’
  - ‘fsr’
  - ‘bsr’
  - ‘rewind’
  - ‘offline’, ‘rewoffl’, ‘eject’
  - ‘status’
  - ‘bsfm’
  - ‘eom’
  - ‘retension’
  - ‘erase’
  - ‘asf’
  - ‘fsfm’
  - ‘seek’

Say, what? I’ve been using Unix-like systems for REDACTED years, but I don’t remember ever having used an mt command. And so I checked the fine manual:

MT(1)                              GNU CPIO                              MT(1)

       mt - control magnetic tape drive operation

       mt [-V] [-f device] [--file=device] [--rsh-command=command] [--version]
       operation [count]

       This manual page documents the GNU version  of  mt.   mt  performs  the
       given operation, which must be one of the tape operations listed below,
       on a tape drive.

       The  default  tape  device  to  operate  on  is  taken  from  the  file
       /usr/include/sys/mtio.h  when  mt is compiled.  It can be overridden by
       giving a device file name in the environment variable TAPE or by a com‐
       mand  line  option  (see  below),  which also overrides the environment

Now I admit that I am not too keen to upgrade my Ubuntu, but it’s not that ancient, either. It turns out that an Ubuntu distribution released in 2018 actually installs a program to control magnetic tape drive operation! I know, I know, the program is likely useful for other things as well, and tar is technically also short for “tape archiver”, but it still feels a bit silly to carry this cruft into the 21st century.

And people say that Windows is arcane in its support for DOS graphics and x86 addressing modes.

One thought on “Control your magnetic tapes”

  1. Tape evolved in parallel with harddrives, it just never reached the consumer market. The current technology is called LTO-8, a cartridge carries 12TB, and the tape drive is connected with fiber optics to handle the high throughput.
    The Linux commands are very much still in use and their robustness is highly appreciated.

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