sort question

[Paul Houtz]

guy at auspex.auspex.com (Guy Harris) writes:

>Try: sort +10 -11 +2 -3 filename
>
>This tells sort to sort first on a field starting in col. 10 and ending just
>before col. 11,

No, it doesn't, at least not if you're talking about the standard UNIX
versions of "sort".  It tells "sort" to sort first on the 10th *field*
(that is, the 11th field on the line - after all, it's written in C
:-)).  Fields are normally separated by white space; with the "-t" flag,
they're separated by tab columns. 
----------

Right.  There is no way to do a true column sort using this utility as you
can on IBM or MPE systems and here is why:   Sort requires a FIELD DELIMITER
character.   That means that there is SOME character that will never be 
sorted.   If you need to sort data from a foreign file about which you have
little information except column numbers to sort on, you are (as far as I
know) out of luck with 'sort'.

If, however, you do know of some character which will NEVER appear as 
data in a file, then you can do a column sort.   For instance, say you
know that the charactyer '^' never appears in your data file.  Then you
can simply say:

sort -t^ -0.0 + 0.3   

This command assumes that there is only ONE field in the file, and that is
the entire record.  It then sorts the 0+0th column of the 0+0th field 
thru the 0+4th column of the 0+0th field, actually accomplishing a sort
of column 1 thru 4.

Here is the worst one I have seen on Unix.  I converted this myself from a
sort done on an IBM System/34.  This is a good example of a COMMON type of
sort done in the commercial world which you never see on Unix:

sort -dt'\012' +0.6 -0.8 +0.13 -0.15 +0.15r -0.17r +0.8 -0.13  DISK-SUMARY >SUM1

This guy sorts the summary file using the newline character as a field 
delimiter (i.e., no fields), and you can tell what column ranges are 
being sorted by subtracting 1 from the 'x' field of the 0.x parms.  

It sorts the 5  thru 7  columns in ascending order, 
         the 12 thru 14 columns in ascending order,
         the 14 thru 16 columns in DESCENDING order, (the "r" after the column)
    then the 7  thru 12 columns in ascending order.

If anyone ever tries to tell you that UNIX is user friendly, you can now
barf on them.  


Paul Houtz
HP Technology Access Center
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Cupertino, Ca 95014
(408) 725-3864
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