extended regular expressions

wakatana · 10-19-2009, 04:27 PM

Hi all how can I write regexp for matching all lines of this file ?

Code:

marek@cepi:~$ cat vystup 
Hakin9.01.2009.pdf
Hakin9.02.2009.pdf
Hakin9.03.2009.pdf
Hakin9.04.2009.pdf
Hakin9.05.2009.pdf
hakin9.06.2009.pdf
hakin9.07-08.2009.pdf

I tried:

Code:

grep -oE "Hakin9.([0-9][0-9])|([0-9][0-9]-[0-9][0-9]).2009.pdf" vystup 
Hakin9.01
Hakin9.02
Hakin9.03
Hakin9.04
Hakin9.05
07-08.2009.pdf

Code:

grep -oE "Hakin9.(([0-9][0-9])|([0-9][0-9]-0-9]0-9])).2009.pdf" vystup
Hakin9.01.2009.pdf
Hakin9.02.2009.pdf
Hakin9.03.2009.pdf
Hakin9.04.2009.pdf
Hakin9.05.2009.pdf

but as you can see did not gives me what I expect.

also I want know if I am capable using extended regular expressions with SED (in man there is "-r" option, I tried it but then noticed I have wrong regexps)

Thanks a lot

sycamorex · 10-19-2009, 04:47 PM

If I'm not mistaken simple:

Code:

grep "[hH]akin9.*pdf" vystup

will do.

You should be able to make use of ERE with the -r flag.
edit: Can you post your SED example that you've got problems with?

pixellany · 10-19-2009, 04:47 PM

For starters, your file has both "Hakin" and "hakin", so you need the first part of the regex to be like this:

[Hh]akin9

No time at the moment to dig further.

markush · 10-19-2009, 05:07 PM

Hi wakatana,

Code:

egrep '[Hh]akin09\.0[0-7](\.|-0[0-8]\.)2009' vystup

works for me.

Markus

wakatana · 10-20-2009, 04:48 AM

Hi guys thanks for yours reply, I used wrong expression, missing '[' before '0' in

Code:

 grep -oE "Hakin9.(([0-9][0-9])|([0-9][0-9]-0-9]0-9])).2009.pdf" vystup

and also [Hh] for upper or lowercase of course.

so it should be

Code:

 grep -oE "[Hh]akin9.(([0-9][0-9])|([0-9][0-9]-[0-9][0-9])).2009.pdf" vstup

sorry I typed in very late night for me

, thank you

wakatana · 10-20-2009, 05:20 AM

I have one question about sed

Code:

cat zoznam 
Hakin9.01.2009.pdf
Hakin9.02.2009.pdf
Hakin9.03.2009.pdf
Hakin9.04.2009.pdf
Hakin9.05.2009.pdf
hakin9.06.2009.pdf
hakin9.07-08.2009.pdf

Desired output

Code:

2009.01.pdf
...
2009.07-08.pdf

so I typed:

Code:

sed -rn 's/[Hh]akin9.\((([0-9][0-9])|([0-9][0-9]-[0-9][0-9]))\).\(2009\).pdf/\2.\1.pdf/gp' zoznam

but gives me nothing

Seems like regexp memory did not works, because following command gives that:

Code:

sed -rn 's/[Hh]akin9.(([0-9][0-9])|([0-9][0-9]-[0-9][0-9])).2009.pdf/pdf/gp' zoznam 
pdf
pdf
pdf
pdf
pdf
pdf
pdf

what I am doing wrong ?
Thanks a lot

pixellany · 10-20-2009, 05:45 AM

If you are using extended regexes (-r flag), then you don't escape the parentheses when using a backreference.

e.g.:

sed -r 's/j(um)p/\1/'

matches "jump", and replaces it with "um"

ghostdog74 · 10-20-2009, 06:03 AM

Quote:

Originally Posted by wakatana

I have one question about sed

Code:

cat zoznam 
Hakin9.01.2009.pdf
Hakin9.02.2009.pdf
Hakin9.03.2009.pdf
Hakin9.04.2009.pdf
Hakin9.05.2009.pdf
hakin9.06.2009.pdf
hakin9.07-08.2009.pdf

Desired output

Code:

2009.01.pdf
...
2009.07-08.pdf

so I typed:
[CODE]

Code:

#!/bin/bash
while IFS="." read -r -a arr 
do
    a="${#arr[*]}"
    unset arr[$a-2]
    s="${arr[@]}"
    s="${s// /.}"
    echo $s
done < "file"

output

Code:

$ more file
Hakin9.01.2009.pdf
Hakin9.02.2009.pdf
Hakin9.03.2009.pdf
Hakin9.04.2009.pdf
Hakin9.05.2009.pdf
hakin9.06.2009.pdf
hakin9.07-08.2009.pdf

$ ./shell.sh
Hakin9.01.pdf
Hakin9.02.pdf
Hakin9.03.pdf
Hakin9.04.pdf
Hakin9.05.pdf
hakin9.06.pdf

wakatana · 10-20-2009, 02:31 PM

ghostdog74: thank you for your post but I have no idea how you did it, I have to study bash a little more

pixellany: I did not knew about that with extended regular exprssions, this is what i was looking foor, thank you

Code:

sed -rn 's/[Hh]akin9.(([0-9][0-9])|([0-9][0-9]-[0-9][0-9])).(2009).pdf/\4.\1.pdf/gp' subor
2009.01.pdf
2009.02.pdf
2009.03.pdf
2009.04.pdf
2009.05.pdf
2009.06.pdf
2009.07-08.pdf

pixellany · 10-20-2009, 07:21 PM

Glad to see things are working....

I don't know if I will ever figure out how to remember what works in extended regexes, and in which utilities.....I always have to test it.

wakatana · 10-21-2009, 01:10 AM

Heh

so am I, some cheat sheet would be nice, I have found one is in czech language but if you are familiar with regexp I think it should not be problem.

http://i.iinfo.cz/r/old/data/tabulka.pdf

chrism01 · 10-21-2009, 08:46 PM

The best book: http://regex.info/

markush · 10-22-2009, 01:27 AM

Hello together,

Quote:

Originally Posted by chrism01

The best book: http://regex.info/

yes, it is. The book of Jeffrey E. F. Friedl is very exciting and it helps at once. While reading it I found me using more elaborate regular expressions and much of my scripting became easier and more efficient.

Markus