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Need Help with a sed command involving Regex

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# 1  
Old 11-28-2013
Need Help with a sed command involving Regex
Hi,
Iam a newbie to SED. I'm faced with a problem as described.

Given the file with text
Code:
1  rwerwerwe rere                         
2  fdfefefe fsdfds                        
3  rerere ffff trtrt                      
4  aaaa 1234 asadsdsd                     
5  hfjfjfjsjfsf shfshfsjhshs              
6  dssssdsdsdd                            
7  dsgdshgsdgdsdgssgdsgdsdhsgdshgshdshdg  
8  kjjkjkj         0---+---0              
9  gfhdfgdfhfgdhhfgdhfgd                  
10 sgdhsgdhsdgsdhgsdgsdhhdg               
11 1234hjhhh ghgsggdgdg                   
12 dddhhdjdhdh                            
13 dagdhdgahadgadg  0---0---+

I want to output two lines , line no 8 and line no 4 .The condition being the first occurrence of 0- or -0 and then the looking back and selecting the line with 1234.
So the two lines out put would be
Code:
aaaa 1234 asadsdsd  
kjjkjkj         0---+---0

Rgds
SShinde
Last edited by Scott; 11-28-2013 at 12:55 PM.. Reason: Please use code tags for code and data
# 2  
Old 11-28-2013
You may try awk approach

Code:
$ awk '/1234/{p=$0;X=NR}/0\-|\-0/ && NR-X == 4{print p RS $0}' file
aaaa 1234 asadsdsd
kjjkjkj 0---+---0

OR
Code:
$ tac file| awk '/0\-|\-0/{p=$0;X=NR}/1234/ && NR - X == 4{print p RS $0}' | tac
aaaa 1234 asadsdsd
kjjkjkj 0---+---0

# 3  
Old 11-28-2013
Hi,
@SShinde: Why lines 11 and 13 don't work ?

Regards.
# 4  
Old 11-28-2013
Hi Akshay,
Works like a charm on the text snippet that I had attached earlier.
Somehow it is not working on the text snippet that I'm working on :-

Snippet starts :-
Code:
-------------------------------------------------
               Load step no.                          =     1                       
               Load increment scaled to                                             
               maximum load level                                                   
                                                                                    
               Load increment                         =    1.000                    
               New load level                         =    1.000                    
               Current stiffness parameter            =    1.000                    
               Solution accuracy parameter            =  3.848*E-00009              
               Determinant of tangential matrix       =  4.427*E189782              
               Number of Negative Pivot Element       =        0                    
               Total energy absorbtion                =  8.734*E 00006              
                                                                                    
                                                                                    
                                                                                    
  --------    I N T E R A C T I O N   F U N C T I O N   V A L U E S  Fb(Fy) ---     
                                                                                    
     ELEM  ES     Node1         Midspan         Node2                               
                                                                                    
     1446   0 -0.44(-0.29)  -0.73(-0.65)  -1.00(-1.00)                              
     1447   0 -0.51(-0.47)  -0.55(-0.52)  -0.60(-0.57)                              
     1448   0 -0.42(-0.38)  -0.46(-0.42)  -0.51(-0.47)                              
     1449   0 -0.40(-0.25)  -0.71(-0.63)  -0.98(-0.98)                              
     1451   0 -0.51(-0.48)  -0.55(-0.52)  -0.59(-0.56)                              
     1453                                               Yield at end 1              
     1453                                               Yield at end 2              
     1453   3 -0.07( 0.21)  -0.82(-0.74)  -0.21( 0.04)         O---+---O            
     1454   0 -0.12(-0.05)  -0.24(-0.18)  -0.38(-0.33)                              
     1455                                               Yield at end 2

-----------Snippet Ends------------

I'm working to isolate two lines namely :-
Code:
New load level                         =    1.000  
1453   3 -0.07( 0.21)  -0.82(-0.74)  -0.21( 0.04)         O---+---

I did try to change the awk command but I'm getting a null string as output.
Rgds
SShinde

---------- Post updated at 01:42 PM ---------- Previous update was at 12:34 PM ----------

Hi Akshay,
Discovered a shortcoming in the awk command .
The awk command is
Code:
awk '/1234/{p=$0;X=NR}/0\-|\-0/ && NR-X == 4{print p RS $0}' file

In the awk command, the absolute value of 4 is creating the problem.
After finding 0- or -0 , I look back till I find 1234, which may occur more than 4 lines behind the first occurrence of 0- or -0.

Can this be rectified !

Rgds
SShinde

Moderator's Comments:
Mod Comment Please use code tags for code and data
Last edited by Scrutinizer; 11-28-2013 at 03:18 PM.. Reason: code tags
# 5  
Old 11-28-2013
Hi,
I don't all understand, but try:
Code:
sed -n '/0-/{x;p;x;p;q;};/-0/{x;p;x;p;q;};/1234/x' file

Regards.
# 6  
Old 11-28-2013
Hi disedorgue,
Thanks, it works.
Would it be possible for you to explain this sed command , as I want to learn SED.
Rgds
SShinde
# 7  
Old 11-28-2013
Moving targets make solutions difficult. Plus, is it "O---+---O" or "0---+---0" that you are looking for? Anyhow, try
Code:
tac file | awk '/O[+-]+O/ {L=1; print} /New load/ && L {L=0; print} ' | tac
               New load level                         =    1.000                    
     1453   3 -0.07( 0.21)  -0.82(-0.74)  -0.21( 0.04)         O---+---O
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