Match a pattern in linux

knoweledgeseeker · 08-18-2012, 06:22 PM

hello,

I want to look for the below pattern in my file.
x can be any number (one or more digits). Everything else in the paragraph i want it be exactly the same.

I ve been trying to do that for more than 6 hours now :s I i googled this problem and found that there is a grep command line i tried to understand how it works and use it but with no vain. then i tried studying the "regular expressions" but that will take me forever before i know how to do that :s
Can anybody please help me with this ! i am stuck . I need this command bcz it will help me automate the process of computing the the result of my experiments which i need very soon

Code:

Node: x Time: xs Ipv4ListRouting table
  Priority: 5 Protocol: ns3::olsr::RoutingProtocol
Destination	NextHop		Interface	Distance
10.1.1.1           x.x.x.x		x		x	
10.1.1.2	        x.x.x.x		x		x	
10.1.1.3		x.x.x.x		x		x	
10.1.1.4		x.x.x.x		x		x
10.1.1.5		x.x.x.x		x		x
10.1.1.6		x.x.x.x		x		x
10.1.1.7		x.x.x.x		x		x
10.1.1.8		x.x.x.x		x		x
10.1.1.9		x.x.x.x		x		x
10.1.1.10		x.x.x.x		x		x

your help is highly appreciated

Ygrex · 08-18-2012, 06:57 PM

please, show the output you are expecting to get

Code:

$ echo 'Node: 0123 Time: 1s Ipv4ListRouting table' | sed -r 's@ [0-9]+@ _M_A_T_C_H_E_D_@g'
Node: _M_A_T_C_H_E_D_ Time: _M_A_T_C_H_E_D_s Ipv4ListRouting table

knoweledgeseeker · 08-18-2012, 07:04 PM

Thank you for your reply .

here is a snippet of the file that I want to look into

Code:

  HNA Routing Table:
  Priority: 0 Protocol: ns3::Ipv4StaticRouting
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
127.0.0.0       0.0.0.0         255.0.0.0       U     -      -      -   0
10.1.1.0        0.0.0.0         255.255.255.0   U     -      -      -   1

Node: 2 Time: 3s Ipv4ListRouting table
  Priority: 5 Protocol: ns3::olsr::RoutingProtocol
Destination		NextHop		Interface	Distance
10.1.1.1		10.1.1.1		1		1	
10.1.1.2		10.1.1.2		1		1	
10.1.1.4		10.1.1.4		1		1	
10.1.1.5		10.1.1.5		1		1	
10.1.1.7		10.1.1.7		1		1	
10.1.1.8		10.1.1.8		1		1	
10.1.1.9		10.1.1.9		1		1	
 HNA Routing Table:
  Priority: 0 Protocol: ns3::Ipv4StaticRouting
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
127.0.0.0       0.0.0.0         255.0.0.0       U     -      -      -   0
10.1.1.0        0.0.0.0         255.255.255.0   U     -      -      -   1

Node: 3 Time: 3s Ipv4ListRouting table
  Priority: 5 Protocol: ns3::olsr::RoutingProtocol
Destination		NextHop		Interface	Distance
10.1.1.2		10.1.1.2		1		1	
10.1.1.3		10.1.1.3		1		1	
10.1.1.5		10.1.1.5		1		1	
10.1.1.8		10.1.1.8		1		1	
10.1.1.9		10.1.1.9		1		1	
10.1.1.10		10.1.1.10		1		1

I want to retrieve all tables in which the destination column have all the ips from 10.1.1.1 to 10.1.1.10
so that is the output i am expecting :

Code:

Node: x Time: xs Ipv4ListRouting table
  Priority: 5 Protocol: ns3::olsr::RoutingProtocol
Destination	NextHop		Interface	Distance
10.1.1.1           x.x.x.x		x		x	
10.1.1.2	        x.x.x.x		x		x	
10.1.1.3		x.x.x.x		x		x	
10.1.1.4		x.x.x.x		x		x
10.1.1.5		x.x.x.x		x		x
10.1.1.6		x.x.x.x		x		x
10.1.1.7		x.x.x.x		x		x
10.1.1.8		x.x.x.x		x		x
10.1.1.9		x.x.x.x		x		x
10.1.1.10		x.x.x.x		x		x

any idea how to get all paragraphs that look like the above expected output ?

Ygrex · 08-19-2012, 01:53 AM

ok, if you want to do it with scripting, then awk tool is what you need, or you can do that with pure bash script reading input line-by-line; though it seems to me that some language like lua/perl/python would fit your needs better

dru8274 · 08-19-2012, 05:42 AM

Using some unrefined awk, this might do it...

Code:

awk '/^10\.1\.1\.([0-9]|10)\t/ { x[n++]=$0 }
     /^Node: [0-9]+ Time: [0-9]+s/ {
          if (n>0) { print "\n",z1,"\n",z2,"\n",z3
                     for (j=0; j<n; j++) print x[j] }
          z1=$0; getline; z2=$0; getline; z3=$0; n=0 }
     END{ if (n>0) { print "\n",z1,"\n",z2,"\n",z3;
                     for (j=0; j<n; j++) print x[j] } }' data.dat

Happy with ur solution... then tick "yes" and mark as Solved!

pixellany · 08-19-2012, 07:10 AM

Quote:

then i tried studying the "regular expressions" but that will take me forever before i know how to do that

Well, you are not going to do it without using regular expressions.....I'd recommend taking the time to learn the basics.

When You are trying to match patterns, think carefully about the criteria. For example, if all the IPs start with "10.1.1", then matching them is trivial. (The regular expression required to match any legal IP is a bit messy)