Why does cat not use options the way I expect UNIX programs to use switches?

Posted by Chas. Owens on Super User See other posts from Super User or by Chas. Owens
Published on 2010-06-09T11:55:17Z Indexed on 2010/06/09 12:02 UTC
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command-line

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unix

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cat

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options

I have been a UNIX user for more years than I care to think about, and in that time I have been trained to expect that when contradictory switches are given to a program the last one wins. Recently I have noticed that

cat -bn file

and

cat -nb file

both use the -b option (number blank lines) over the -n option (number all lines). I get this behavior on both BSD and Linux, so I don't think it is an implementation quirk. Is this something that is specified somewhere and am I just crazy for expecting the first example to number all lines?

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