topic Re: Shell Script Help in Operating System - Linux

Shell Script Help

Steven Chen_1 — Fri, 24 Feb 2006 09:19:57 GMT

Hope someone can help:

I have the following script:

sed -e 's/EMAIL_ADDR_TXT/AGENCY_LOCATION/'
-e 's/CONT_EMAIL_ADDR_TXT/AGENCY_CONTACT/'
-e 's/EMX_ADDR/WEB_APPLICANT/'
-e 's/SITE_EMAIL_ADDR_TXT/RESOURCE_LOCATION/' $BADMAIL>badmail1

but the result is all words of EMAIL_ADDR_TXT have been changed to AGENCY_LOCATION, the first sed choice.

I need some field protection and change the word to exactly what it means. But using [ ] to include words still not working. Nor I succeeds in using " " to protect.

Any comments are appreciated.

Re: Shell Script Help

Peter Godron — Fri, 24 Feb 2006 09:26:16 GMT

Steven,
is there a field seperator in the file?

If, for example it is "," you could do
sed -e's/,EMAIL_ADDR_TXT,/,AGENCY_LOCATION,/

Re: Shell Script Help

James R. Ferguson — Fri, 24 Feb 2006 09:32:46 GMT

Hi Steven:

You need to provide a better regular expression -- one that uniquely identifies the boundries of a match/substitution.

For example, anchor EMAIL_ADDR_TXT to the beginning of a line with a caret:

sed -e 's/^EMAIL_ADDR_TXT/

You can anchor at the end of a line with a dollar sign ($). You can use spaces and tabs too to form logical boundries.

Far, far superior to 'sed' is 'perl'. Perl has some of the very best regular expression support you can find, in my opinion.

Regards!

...JRF...

Re: Shell Script Help

renarios — Fri, 24 Feb 2006 09:37:30 GMT

Hi Steven,

I guess you need to use the global option (/g) option, just like in vi :%s///g

So the syntax would be:
sed -e 's/EMAIL_ADDR_TXT/AGENCY_LOCATION/g'\
-e 's/CONT_EMAIL_ADDR_TXT/AGENCY_CONTACT/g'\
-e 's/EMX_ADDR/WEB_APPLICANT/g'\
-e 's/SITE_EMAIL_ADDR_TXT/RESOURCE_LOCATION/g'\
$BADMAIL>badmail1

Cheers,

Renarios

Re: Shell Script Help

Arunvijai_4 — Fri, 24 Feb 2006 09:57:43 GMT

Hi,

A very good reading about "sed"

http://www.student.northpark.edu/pemente/sed/sed1line.txt

-Arun

Re: Shell Script Help

Peter Nikitka — Fri, 24 Feb 2006 11:10:43 GMT

Hi,

as a first change, you could change the order of the sed-commands: since the command sequence of sed is in serial order, put the longest strings first: they have been changed already when sed executes the following command(s).
sed -e 's/CONT_EMAIL_ADDR_TXT/AGENCY_CONTACT/'
-e 's/SITE_EMAIL_ADDR_TXT/RESOURCE_LOCATION/'
-e 's/EMAIL_ADDR_TXT/AGENCY_LOCATION/' ...

If there is always at least one character of text before the search pattern, you can anchor it (like the other posters suggested). Pattern starting at the beginning of a line must be added seperately:

sed -e 's/$[^_]$EMAIL_ADDR_TXT/\1AGENCY_LOCATION/' -e 's/^EMAIL_ADDR_TXT/AGENCY_LOCATION/'
..
and so on. If the overlapping search pattern differ not in the '_' unterline, the anchor pattern has to be refined, perhaps you need a different anchor pattern for the end of the search pattern.

mfG Peter

Re: Shell Script Help

Sandman! — Fri, 24 Feb 2006 11:13:42 GMT

Hello!

I'm not sure if your question has been answered by one of the aforementioned posts, but it'll help if you could attach a portion of the input file on which these sed substitutions have to occur. These would definitely help in providing an accurate solution to your problem.

cheers!

Re: Shell Script Help

Arturo Galbiati — Fri, 24 Feb 2006 11:15:15 GMT

Hi,
try:
sed -e 's/SITE_EMAIL_ADDR_TXT/RESOURCE_LOCATION/'
-e 's/CONT_EMAIL_ADDR_TXT/AGENCY_CONTACT/'
-e 's/EMX_ADDR/WEB_APPLICANT/'
-e 's/EMAIL_ADDR_TXT/AGENCY_LOCATION/' $BADMAIL>badmail1

Since Sed exceutes the commands in order, first chnage the long pattern and after the pattern contained into previous pattern already chnaged.
HTH,
Art

Re: Shell Script Help

Steven Chen_1 — Fri, 24 Feb 2006 11:57:25 GMT

I am going to attach original source file "badmail.lst" (=$BADMAIL) and the resulting file using my script. Maybe you could find out the solution.

Thanks a lot and have fun.

Re: Shell Script Help

Arunvijai_4 — Fri, 24 Feb 2006 12:04:30 GMT

Hello Steven,

What exactly you want to do ? Its always better to use perl for regular expressions.

http://www.english.uga.edu/humcomp/perl/regex2a.html

-Arun

Re: Shell Script Help

Sandman! — Fri, 24 Feb 2006 13:03:11 GMT

Steven,

Try the ex script provided below. It's more useful than sed as it can anchor words with \< (start-of-word) \> (end-of-word) and substitute exactly those instead of substrings that are contained within words. In other words it provides the field protection you are looking for.

# ex -s $BADMAIL<> 1,$ s/\/AGENCY_LOCATION/g
> 1,$ s/\/AGENCY_CONTACT/g
> 1,$ s/\/WEB_APPLICANT/g
> 1,$ s/\/RESOURCE_LOCATION/g
> w badmail1
> EOF

In fact it can modify the input file without having to pipe stdout to another file. If you wanted to modify and save the changes to $BADMAIL itself then change the "w badmail1" command to "wq" i.e.

# ex -s $BADMAIL<> 1,$ s/\/AGENCY_LOCATION/g
> 1,$ s/\/AGENCY_CONTACT/g
> 1,$ s/\/WEB_APPLICANT/g
> 1,$ s/\/RESOURCE_LOCATION/g
> wq
> EOF

hope it helps!

Re: Shell Script Help

James R. Ferguson — Fri, 24 Feb 2006 13:03:52 GMT

Hi Steven:

If I read your requirements and attachments correctly, simply adding the beginning-of-line anchor (the caret) to each substitution (as follows) will produce what you want:

sed -e 's/^EMAIL_ADDR_TXT/AGENCY_LOCATION/'
-e 's/^CONT_EMAIL_ADDR_TXT/AGENCY_CONTACT/'
-e 's/^EMX_ADDR/WEB_APPLICANT/'
-e 's/^SITE_EMAIL_ADDR_TXT/RESOURCE_LOCATION/' $BADMAIL>badmail1

Regards!

...JRF...

Re: Shell Script Help

Steven Chen_1 — Fri, 24 Feb 2006 14:15:13 GMT

As always, I am fascinated by the overwhelming support and the precise solution folks are providing!

for the benefit of all, my trial passes and the verdict comes out that JRF's solution is simple, precise and get the work done!

Thank you all!