Bash malfunction, or something else ??

[Gain Paolo Mureddu]

David Curry wrote:

> Richard Hubbell wrote:
>
>> Since you don't really give the details I would bet
>> that you're expecting cdrecord to print only on stdout but it
>> probably prints to stderr as well.
>>
>> Capture stdout and stderr to a file and see if that is what you expect.
>>
>> cdrecord -scanbus 2>&1 myfile
>>
>> Richard
>>
>> On Sun, 23 Jan 2005 22:44:09 -0500, David Curry 
>> <dsccable at comcast.net> wrote:
>>  
>>
>>> Reference materials on commands and features of BASH that I have
>>> consulted include material stating that a line command in the form
>>>
>>> $ command [options] [directory (if different than the current 
>>> directory)
>>> ] > [filename]
>>>
>>> will re-direct the output of the command from stdout to the named file.
>>>
>>> In evaluating the installation of FC2 on my PC (box?), I have noticed a
>>> difference between outputs sent to stdout and outputs to > [filenames].
>>>
>>> Is this a bug?
>>>
>>> To illustrate, cdrecord -scanbus > scanbus.txt on my machine produces
>>> the following text file.
>>>
>>> listing of scanbus.txt:
>>> Cdrecord-Clone 2.01-dvd (i686-pc-linux-gnu) Copyright (C) 1995-2004
>>> Jörg Schilling
>>> Note: This version is an unofficial (modified) version with DVD support
>>>
>>> Note: and therefore may have bugs that are not present in the original.
>>> Note: Please send bug reports or support requests to 
>>> http://bugzilla.redhat.com/bugzilla
>>> Note: The author of cdrecord should not be bothered with problems in 
>>> this version.
>>> Using libscg version 'schily-0.8'.
>>> scsibus1:
>>>        1,0,0   100) 'ATAPI   ' 'CD-R/RW 24X10   ' 'P.MJ' Removable 
>>> CD-ROM
>>>        1,1,0   101) 'LITEON  ' 'CD-ROM LTN301   ' 'MM07' Removable 
>>> CD-ROM
>>>        1,2,0   102) *
>>>        1,3,0   103) *
>>>        1,4,0   104) *
>>>        1,5,0   105) *
>>>        1,6,0   106) *
>>>        1,7,0   107) *
>>>
>>> Output of cdrecord -scanbus directed to stdout reads
>>>
>>> Cdrecord-Clone 2.01-dvd (i686-pc-linux-gnu) Copyright (C) 1995-2004 
>>> Jörg Schilling
>>> Note: This version is an unofficial (modified) version with DVD support
>>> Note: and therefore may have bugs that are not present in the original.
>>> Note: Please send bug reports or support requests to 
>>> http://bugzilla.redhat.com/bugzilla
>>> Note: The author of cdrecord should not be bothered with problems in 
>>> this version.
>>> scsidev: 'ATA'
>>> devname: 'ATA'
>>> scsibus:  -2 target:  -2 lus:  -2
>>> Linux sg driver version: 3.5.27
>>> Using libscg version 'schily-0.8'.
>>> cdrecord:  Warning: using inofficial libscg transport code version 
>>> (schily - Red Hat-scsi-linux-sg.c-1.83-RH '@(#)scsi-linux-sg.c     
>>> 1.83 04/05/20 Copyright 1997 J. Schilling').
>>> scsibus1:
>>>        1,0,0   100) 'ATAPI   ' 'CD-R/RW 24X10   ' 'P.MJ' Removable 
>>> CD-ROM
>>> cdrecord:  warning: controller returns wrong size for CD 
>>> capabilities page.
>>>        1,1,0   101) 'LITEON  ' 'CD-ROM LTN301   ' 'MM07' Removable 
>>> CD-ROM
>>>        1,2,0   102) *
>>>        1,3,0   103) *
>>>        1,4,0   104) *
>>>        1,5,0   105) *
>>>        1,6,0   106) *
>>>        1,7,0   107) *
>>>
>>> There are six more lines of output sent to the display screen than 
>>> are sent to a file via use of the > [filename] option in BASH.
>>>
>>> -- 
>>> fedora-list mailing list
>>> fedora-list at redhat.com
>>> To unsubscribe: http://www.redhat.com/mailman/listinfo/fedora-list
>>>
>>>   
>>
>>
>>  
>>
> Thanks, Richard.  As far as I knew all cdrecord -scanbus output was 
> displaying on my monitor (stdout) and did not know that the first four 
> lines omitted from the disk file I created were "errors" (scsidev: 
> "ATA" -->  Linux sg driver version: 3.5.27).
>
> Following Up on the suggestions of Jason Tibbits and Jim Cox, I 
> repeated the exercise using &> instead of just > and the file produced 
> included all of the missing lines.
>
> Thanks again to all who responded.
>
They are not errors perse... They may be warnings too, which are also 
treated as errors and thus displayed to stderr, which also happens to be 
the monitor ;)