Login or Register to Ask a Question and Join Our Community


UNIX for Dummies Questions & Answers

Grep issue

 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers Grep issue
# 1  
Old 07-28-2011
Question Grep issue
Code:
more Hello.txt

it was a sunny way and i was about to go home.

I need to grep and redirect to a new file all the text between 'sunny' and 'go' string above.

Note: There may be multiple lines in between the string i need to grep between. If there are multiple 'go' strings it should grep till the last 'go' string is found in the text file.

Can you please quick help ?

Regards,
Mohtashim
Last edited by pludi; 07-28-2011 at 11:38 AM..
# 2  
Old 07-28-2011
What is your system? What is your shell?
# 3  
Old 07-28-2011
You can't do it with grep. With perl it's easy. And this should work on all *nixes:
Code:
sep=`echo : | tr : '\01'`
cat INPUTFILE | tr '\n' $sep  | sed 's/^.*\(sunny.*go\).*$/\1/' | tr $sep '\n'

If there are several "sunny.*go" in the file then only the last would match.
# 4  
Old 07-28-2011
Useless Use of Cat
# 5  
Old 07-28-2011
Useful use of cat(1)
"easy "intuitive" switching on the command line between different types input"
# 6  
Old 07-28-2011
"The fact that the same thread ("but but but, I think it's cleaner / nicer / not that much of a waste / my privelege to waste processes!") springs up virtually every time the Award is posted is also Ancient Usenet Tradition." -- uuoc

You can get the same ordering without it anyway:

Code:
<filename program ...

So it's a bad habit with zero benefits.
# 7  
Old 07-28-2011
From Bash cookbook:

Useless Use of cat
Certain Unix users take a positively giddy delight in pointing out inefficiencies in
other people's code. Most of the time this is constructive criticism gently given and
gratefully received.
Probably the most common case is the so-called “useless use of cat award” bestowed
when someone does something like cat file | grep foo instead of simply grep foo
file. In this case, cat is unnecessary and incurs some system overhead since it runs in
a subshell. Another common case would be cat file | tr '[A-Z]' '[a-z]' instead of
tr '[A-Z]' '[a-z]' < file. Sometimes using cat can even cause your script to fail (see
Recipe 19.8, “Forgetting That Pipelines Make Subshells”).
But... (you knew that was coming, didn't you?) sometimes unnecessarily using cat
actually does serve a purpose. It might be a placeholder to demonstrate the fragment
of a pipeline, with other commands later replacing it (perhaps even cat -n). Or it
might be that placing the file near the left side of the code draws the eye to it more
clearly than hiding it behind a < on the far right side of the page.
While we applaud efficiency and agree it is a goal to strive for, it isn't as critical as it
once was. We are not advocating carelessness and code-bloat, we're just saying that
processors aren't getting any slower any time soon. So if you like cat, use it.

The good book, btw.
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Issue with Grep

Hi guys, Hope someone can help me with this - I'm sure it's fairly simple but it's driving me mad! (forgive the coding - still new on scripting - come from Windows) I have the following coding for checking whether I want to include a line in a file:- EXTRACT_Date=$(date --date="${PERIOD}"... (6 Replies)
Discussion started by: NickF
6 Replies

2. Shell Programming and Scripting

Issue with grep

Hello, I have an input file that looks like so: LDLR LDLRAD4 VLDLR when I grep "LDLR" I get an output of: LDLR LDLRAD4 VLDLR Since all names have "LDLR" included within them, but all I want the output to be is LDLR I know it can work if I surround the words with pipes for... (5 Replies)
Discussion started by: Rabu
5 Replies

3. UNIX for Dummies Questions & Answers

Grep issue

HI, I have a command to check a license file. License_print. In that file you get the headlines and all different licenses. Now i want to have things extracted from it. so i do like following: license_print | grep -iw -e "user" -e "admin" But i don´t want all lines where user is... (11 Replies)
Discussion started by: Tzwaj
11 Replies

4. Shell Programming and Scripting

Grep issue

Hi Guys, I am new to shell scripting. Need help on grep command. I had a file called file.log which contain below statements. 12 Nov 2013 14:12:17,756 INFO security - Userid: raja, Saved File Instance, Name: , Registry: 23 Nov 2013 14:14:11,777 INFO security - Userid: raja, Saved... (7 Replies)
Discussion started by: Vinoth Kumar G
7 Replies

5. Shell Programming and Scripting

Issue in grep

i have following pattern in file s6:s2 s2:s4 s1:s2:s3:s4:s5:s6 s1 . . Now i want to find occurence of each record in file like s6:s2 occurs twice {once in first record and both occur in 3 record as well} so output should be s6:s2 2 s2:s4 2 s1:s2:s3:s4:s5:s6 :1 s1 : 2 ... (7 Replies)
Discussion started by: sharad.40216
7 Replies

6. Shell Programming and Scripting

Grep issue

Hi All I have a file containing following records: $HEW_TGT_DB2_USER=hbme_bi2 $prmAttunityUser=ais $DS_USER=hbme_bi2 $prmStgUser=hbme_bi2 $prmuser=hbme_bi2 $prmStgPass=hbme_bi2 $prmpwd=hbme_bi2 $prmAttunityUser=ais Say suppose the name of the file is test4.txt When i fire this... (2 Replies)
Discussion started by: vee_789
2 Replies

7. Shell Programming and Scripting

grep issue

The below command is not working stackmem="$(pmap $1 | grep -i '' | awk '{print $2}'| tr -d ' K')" I need to grep strictly for ----> Regards, Mohtashim (2 Replies)
Discussion started by: mohtashims
2 Replies

8. Shell Programming and Scripting

Grep Issue

<record> <set> <termId>1234</termId> <termType>First</termType> </set> <set> <termId>5678</termId> <termType>Second</termType> </set> </record> This is saved in record.xml Hi I have this sample XML that i am grepping using a shell program. The objective of the task is - based... (7 Replies)
Discussion started by: revertback
7 Replies

9. UNIX for Dummies Questions & Answers

Issue with grep

I have a file that has the following: 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 591066 100.0 ... (5 Replies)
Discussion started by: Pablo_beezo
5 Replies

10. UNIX for Dummies Questions & Answers

issue with grep

using grep, i have a file emp.lst, and i want all those records where "S" or "s" (capital or small) is not there i used this grep emp.lst when i use grep emp.lst i am getting rows with S..but why negate (^) is not working? (3 Replies)
Discussion started by: soujanya_srk
3 Replies
Login or Register to Ask a Question