finding the nth match


 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers finding the nth match
# 8  
Old 06-15-2011
Quote:
Originally Posted by countryStyle
See....you did not need data to answer and there was no problem adding on the excellent commentary/lead about awk.
If I lucked out into something that did exactly what you wanted the very first try, then I lucked out. Getting people to explain what they really want can be as difficult as -- well -- as difficult as getting you to post your data.

Simple questions shouldn't always be taken at face value, either
Quote:
Originally Posted by qdb.us
<glyph> For example - if you came in here asking "how do I use a jackhammer" we might ask "why do you need to use a jackhammer"
<glyph> If the answer to the latter question is "to knock my grandmother's head off to let out the evil spirits that gave her cancer", then maybe the problem is actually unrelated to jackhammers
So frequent posters here develop some habitual questions. 1) Post your OS (thank you for that), 2) Post your data! It makes things a lot smoother all around.

Quote:
I know a lot of people often ask for the answer to their specific issue and want YOU the other poster to do all the work for them (sometimes very practical). I am still at the general question looking to get more of a clue phase but if you want to do all my work for me let me know...I am certain you can do it fast.
You know the saying, a bird in the hand is worth two in the bush? It doesn't have to be either/or. I can make a simple example that works with your data without doing all your work for you, which will look more straighforward than one for random data I had lying around.
Quote:
I am not working with large files here and performance is not an issue...... The line is easy to use and works in the Bash shell so....why is this a silly solution, performance, crossplatform issues?
Running one program instead of two is much better, and if you can avoid any programs, that's better yet! External programs take time to start and stop, even for tiny files -- especially for tiny files, where most of the time would be spent loading/quitting instead of work. And pipes can waste time communicating with each other (grep reads, writes, tail reads, writes, head reads, writes.) Both of these can add up faster than you'd expect. One of my first shell programming experiments was a text linewrapper that ran at the blazing speed of one kilobyte per second.

This is also why I'm curious what your program actually is and how you're using this 'get line x' code, because if grep | tail | head is your way of loading individual lines of data from file, you might want to ask about better ways to organize your program.
# 9  
Old 06-15-2011
lol....don't beat yourself up over getting it right the first time. Your answered showed that you are intuitive and knew the simple solution and other possible ones. Me as the guy with a lot of windows scripting experience knew I was not going to jerk everyone around by not providing the data because the answer was simple

A customer goes into a hardware store and asks for a hammer....the sales guys says "what type of hammer? We have 120 different kinds!" and proceeds to name at least a dozen......the customer looks all frazzled and leaves......"all I wanted to do was put a nail in a board".


I am very happy I got my hammer Smilie When I have a something that requires more thinking I will be sure to post data.

thanks!

.
 
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. AIX

Print nth previous line after match

Please help me print nth line after match awk or sed one line command. (3 Replies)
Discussion started by: sushma123
3 Replies

2. Shell Programming and Scripting

sed : replace Nth match in a file

I have a situation where a file "config.txt" looks like this Servername: OS: Serername: OS: Servername: OS: .... .... ... Servername: OS: looking for the sed syntax to replace the "Nth" occurrence of Servername (i would apply the same logic to OS as well), want to replace the Nth... (4 Replies)
Discussion started by: alldbest
4 Replies

3. Shell Programming and Scripting

How to display when nth line match a pattern?

Hi All, I have sample of listing as following Database 2 entry: Database alias = PXRES Database name = PXRES Local database directory = /db2/data1/db2phnx Database release level = d.00 Comment ... (3 Replies)
Discussion started by: ckwan
3 Replies

4. Shell Programming and Scripting

Problem getting Nth match in sed

Hi all, I'm trying to create a sed command to get the Nth instance of an XML tag in a string, but thus far I can only ever seem to get the last one. Given an XML string: <Wrap><GrayLevel>a</GrayLevel><GrayLevel>b</GrayLevel></Wrap> I tried to do this on the command line to get each... (7 Replies)
Discussion started by: Zel2008
7 Replies

5. Answers to Frequently Asked Questions

Finding the nth Particular Week in a Month – shell script

I see lot of request posted in internet to find out the day of nth week in a Month. example: what is the date of 3rd Sunday in October What is the date of 2nd Friday in June 2012 what is the date of 4th Saturday in January 2011..etc.. The below shell script is used to find out the... (1 Reply)
Discussion started by: itkamaraj
1 Replies

6. UNIX for Dummies Questions & Answers

Printing nth and n+1th line after a pattern match

Hi , I want to print the nth and n+1 lines from a file once it gets a pattern match. For eg: aaa bbb ccc ddd gh jjjj If I find a match for bbb then I need to print bbb as well as 3rd and 4th line from the match.. Please help..Is it possible to get a command using sed :) (6 Replies)
Discussion started by: saj
6 Replies

7. Shell Programming and Scripting

Finding Nth Column

Please help me how can I display every nth field present in a "|" delimited file. Ex: If a have a file with data as a|b|c|d|e|f|g|h|k|l|m|n I want to display every 3rd feild which means the output should be c f k n Please help me. (1 Reply)
Discussion started by: ngkumar
1 Replies

8. UNIX for Dummies Questions & Answers

Finding nth line across multiple files

I have several files (around 50) that have the similar format. I need to extract the 5th line from every file and output that into a text file. So far, I have been able to figure out how to do it for a single file: $ awk 'NR==5' text1.txt > results.txt OR $ sed -n '5p' text1.txt > results.txt... (6 Replies)
Discussion started by: oriqin
6 Replies

9. Shell Programming and Scripting

Getting filename for Nth line pattern match

Hi, I have many scripts in particular directory. And few of the scripts have exit 0 in second line. Now i wanted to list out the scripts name which has the exit 0 in its second line I tried many options , but i can not get the filename along with the nth line pattern match :mad:. Can anyone... (14 Replies)
Discussion started by: puni
14 Replies

10. UNIX for Dummies Questions & Answers

Finding nth occurrence in line and replacing it

Hi, I have several files with data that have to be imported to a database. These files contain records with separator characters. Some records are corrupt (2 separators are missing) and I need to correct them prior to importing them into the db. Example: ... (5 Replies)
Discussion started by: stresing
5 Replies
Login or Register to Ask a Question