From: Al Aab <af137@freenet.toronto.on.ca>
Sent: 16 September 1996 20:25

=========================== seders newsletter #5 ===============================

Here is a sed problem for sharp seders.

The original motivation for this hit while reading a post on comp.unix.editor.  
The poster wanted to extract the first field of a UNIX password file. His
problem could be handled with sed, of course, but even primitive sed would be
an overkill. cut would not.

Using a 2-line input file, and sed15 for DOS, I did the following. Can you
comment on the subtle differences between the different sed scripts?
    
sed "p;s/:[^:]+:/----/1" d

	ab:abc:abd:....                                            
    ab----abd:....                                             

    :xyz::xyy::xxx::zzz:                                       
    ----:xyy::xxx::zzz:                                        
                                                           
sed "p;s/:[^:]+:/----/2" d

    ab:abc:abd:....                                            
    ab:abc:abd:....                                            

    :xyz::xyy::xxx::zzz:                                       
    :xyz:----:xxx::zzz:                                        
                                                           
sed "p;s/:[^:]+/----/2" d 

    ab:abc:abd:....                                            
    ab:abc----:....                                            

    :xyz::xyy::xxx::zzz:                                       
    :xyz:----::xxx::zzz:

========================= end of seders newsletter #5 ==========================