Red Hat Bugzilla – Bug 171340
mt man page misdescribes fsfm and bsfm arguments
Last modified: 2013-07-02 19:10:56 EDT
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Description of problem:
The operation of the fsfm and bsfm arguments is mis-described in the mt man page.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Read the mt man page.
Actual Results: The man page includes this description:
bsfm Backward space count files. The tape is positioned on the first
block of the next file.
... and similarly for fsfm.
Expected Results: The bsfm description should say that "The tape is positioned on the first block of the previous file.", and that fsfm moves to the next file.
Even that description is a bit misleading, in that to re-read a tape file that you've just read requires a "bsfm 2" to return to the beginning of the just-read file. Perhaps something brief description of how file marks are used in tape positioning would be in order.
*** Bug 171339 has been marked as a duplicate of this bug. ***
Could you please reformulate the bsfm and fsfm description without any
misleadings to let me fix the man page and send the fix upstream? Thanks.
I'd change the "backward space file mark" command to read:
Backward space past count file marks, then forward space one file record. This
leaves the tape positioned on the first block of the file that is count-1 files
before the current file.
The corresponding change to the "forward space file mark" command should
probably read something like:
Forward space past count file marks, then backward space one file record. This
leaves the tape is positioned on the last block of the file that is count-1
files past the current file.
Just for information, here's how the Solaris man page describes the operation of
the bsf and nbsf commands of the Solaris mt command:
Back space over count EOF marks. The tape is positioned on the
beginning-of-tape side of the EOF mark.
Back space count files. The tape is positioned on the first block of the file.
This is equivalent to count+1 bsf's followed by one fsf.
I find this description easier to read than the one in the current RH man page.
Also, there's a difference in how many files are skipped between the bsfm and
nbsf commands. Under Solaris, an "nbsf 1" moves to the start of the prior file;
under Linux, a "bsfm 2" is required to do the same thing. The Solaris version
of this command seems more in line with what intuition would lead a user to expect.
fsfm and bsfm descriptions are now fixed.
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mt-st-0.9b-1.fc4 has been pushed for FC4, which should resolve this issue. If these problems are still present in this version, then please make note of it in this bug report.