Re: [OT] perl regex problem

[Juan Fuentes <juan.fuentes@codetel.net.do>]

* Hunter Marshall (hmarshall@viasat.com) wrote:
> I am a long time debian and perl user. But obviously long enough!
> Forgive the slight misuse of the list, but can anyone shed light
> on what I'm doing wrong in this attempt to find \n\n in a text file 
> with perl? I'm sure I've done this before.
> 
> Thanks
> 
> 	hunter
> 
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 
> hhm@hmarshall:/tmp
> -> cat junk 
> hi
> 
> 
> 
> 
> 
> 
> hhm@hmarshall:/tmp
> -> od -x junk 
> 0000000 6968 0a0a 0a0a 0a0a 000a
> 0000011
> hhm@hmarshall:/tmp
> -> perl -n -e 'print "yup\n" if /\x0a/;' junk
> yup
> yup
> yup
> yup
> yup
> yup
> yup
> hhm@hmarshall:/tmp
> -> perl -n -e 'print "yup\n" if /\x0a\x0a/;' junk


I'm not sure what you want the result to be but here are my two
assumptions:

1.) You want perl to print yup 4 times ie. 0a0a is 1 unit, there are
four yup; so here is how i did it:

perl -ne 'print "yup\n" if /(\x0a)$1/;' junk

result:
yup
yup
yup
yup

2.) You just want one yup meaning yes there is an x0a in there:

perl -ne 'print "yup\n"; last, if /\x0a/;' junk

result:
yup


I hope this helps.

Juan Fuentes