Visit Our UNIX and Linux User Community


grep and display lines from a file


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting grep and display lines from a file
# 1  
Old 08-25-2009
grep and display lines from a file

I have to grep on a few words in a file and then display the line containing those words and the line above it.

For ex -

File1.txt contains...

abc xyz abc
This is a test
Test successful
abc xyz abc
Just a test
Test successful


I find the words 'Test successful' in the file and then I have to display the line containing these words and the line above it.

So my output should be...

This is a test
Test successful
Just a test
Test successful

I am just not sure how to display the line above the 'Test successful' in my result.
# 2  
Old 08-25-2009
grep -B1 "Test successful" yourfile
# 3  
Old 08-25-2009
var=`grep -n "Test successful" <filename> | cut -f1 -d ":"`

for i in $var
do
head -$i <filename> | tail -2
done
# 4  
Old 08-25-2009
use this awk utility
Code:
awk 'c-->0;$0~s{if(b)for(c=b+1;c>1;c--)print r[(NR-c+1)%b];print;c=a}b{r[NR%b]=$0}' b=1 a=0 s="Test successful" filename

where a=no of lines below the pattern
b=no of lines above the pattern
s=pattern
# 5  
Old 08-25-2009
aster007,

that worked very well...

Can you also let me know how can I get the same result from all files in the directory (using '*') rather than putting <filename>?
# 6  
Old 08-25-2009
Code:
for file in *
do
  var=`grep -n "Test successful" $file | cut -f1 -d ":"`
  for i in $var
  do
    head -$i $file | tail -2
  done
done

# 7  
Old 08-28-2009
That worked awsome!

Thank you -- Peterro and aster007.

Previous Thread | Next Thread
Test Your Knowledge in Computers #307
Difficulty: Easy
The common software-programming acronym 18N comes from the term Interlocalization;.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Display lines for a particular year in a file using grep

hi, I have a log file with data for more than 3 years, i want only the rows for the year 2017, say for example. My file has the data like this 08-OCT-2015 11:17:35 AAA, BBBB 08-OCT-2017 11:17:35 AAA,Bdfdfd,dfdfd,dfd 08-Nov-2017 11:17:35 AAA,Bdfdfd,dfdfd,deree i want the rows... (2 Replies)
Discussion started by: skoshekay
2 Replies

2. Shell Programming and Scripting

Grep and display multiple lines

Hi guys, I have a log file that generates multiple logs about a query. <query time='2016-04-13 13:01:50.825'> <PagingRequestHandler> <Before>brand:vmu</Before> <After>brand:vmu</After> </PagingRequestHandler> <GroupDeviceFilterHandler> <Before>brand:vmu</Before> ... (3 Replies)
Discussion started by: Junaid Subhani
3 Replies

3. Shell Programming and Scripting

Grep pattern and display all lines below

Hi I need to grep for a patter and display all lines below the pattern. For ex: say my file has the below lines file1 file2 file3 file4 file5 I NEED to grep for patter file3 and display all lines below the pattern. do we have an option to get this data. Let me know if you require... (5 Replies)
Discussion started by: venkidhadha
5 Replies

4. Shell Programming and Scripting

Grep multiple exact match, do not display lines

Hi, Need help to grep the following from a file x. I just want to grep exact match not lines and not partial word. CONFSUCCESS CONFFAIL CONFPARTIALSUCCESS >cat x xczxczxczc zczczcxx CONFSUCCESS czczczcczc czxxczxzxczcczc CONFFAIL xczxczcxcczczc zczczczcz CONFPARTIALSUCCESS czczxcxzc ... (4 Replies)
Discussion started by: rajeshwebspere
4 Replies

5. Shell Programming and Scripting

Grep word after last occurance of string and display next few lines

Hi, I wanted to grep string "ERROR" and "WORNING" after last occurrence of String "Starting" only and wanted to display two lines after searched ERROR and WORNING string and one line before. I have following cronjob log file "errorlog" file and I have written the code for same in Unix as below... (17 Replies)
Discussion started by: nes
17 Replies

6. UNIX for Dummies Questions & Answers

Using grep and zgrep then display the next few lines

Hello everyone. I would like to know if I can use grep or zgrep to search for a particular pattern then print the x number of lines after the pattern was found. Lets say for example a pattern was found on line 3, I wanted the output to show lines 3, 4 and 5. Thanks! (10 Replies)
Discussion started by: khestoi
10 Replies

7. Solaris

grep and display few lines before and after

Hi is there a way in grep to display few lines before and after the pattern?? I tried options A and B and after-context and before-context. But they don't work on Solaris platform. please advise. (13 Replies)
Discussion started by: melanie_pfefer
13 Replies

8. UNIX for Dummies Questions & Answers

Grep and display n lines after the match is found.

Hello, How do I use grep to find a pattern in a list of file and then display 5 lines after the pattern is matched Eg: I want to match the string GetPresentCode in all files in a folder and then see 4 lines following this match. I am not sure if grep is what should be used to achieve. Thanks!... (3 Replies)
Discussion started by: cv_pan
3 Replies

9. Shell Programming and Scripting

Display file without # lines

Hi to all in this great forum, im sure this has been asked lots of times before but ive been looking for the past day and cant find the answer. I use cat/some/file to display its contents but how can i get it to not display hashed out lines, or do i need another command, Thanks in advance:) (5 Replies)
Discussion started by: dave123
5 Replies

10. UNIX for Dummies Questions & Answers

display few lines of the file

Hi, If I want to have a look at few lines of the file, how do I, what command to use. Eg: If I have a file having length 2000 lines and I want to have a look at the content between 1400 and 1600, How do I look at it ? Also, If I want to have a look at function alone in a file, how do I go... (4 Replies)
Discussion started by: sharuvman
4 Replies

Featured Tech Videos