Re: Bug in od with "-j" option?

[Eric Blake]

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According to Paul GHALEB on 8/13/2007 10:33 AM:
> 
> IOW, when one tries to skip exactly the size of the file, od acts as if
> it ignored the "-j size" option.

[This mail assumes your sed obeys POSIX on this sequence:

$ seq 3 > foo
$ (sed -n q; cat) < foo
2
3
$

If this is not the case, replace 'sed -n q' with 'head -n1 > /dev/null']

While we're at it, od has another POSIX-compliance bug, when stdin is
seekable and starts life in the middle of the file:

$ seq 3 > blah
$ (sed -n q; od -tx1z -j 7) <blah  # good
od: cannot skip past end of combined input
$ (sed -n q; od -tx1z -j 5) <blah
0000005
$   # seeking 5 puts us past the end; this should have
$   # errored just like -j7

Also, POSIX wasn't too clear on this point, but:

$ (sed -n q; od -tx1z -j 4) <blah
0000004
$   # file started at offset 2; should this report offset 6, not 4?


- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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