command to find a paraprah in a file in linux

[knowledge_Seeker1]

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 3 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.
Can anybody please help me with this ! i am stuck . I need to do find the result of my experiments very soon

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

 

[sky_123]

You actually want to use regular expressions (regexp), but although they can be used with the 'grep' command,
you actually need something else, maybe 'sed' for multi-line.
Grep is ideal if you want to check a single line .
I'd suggest, are you sure that you need to match on the entire paragraph, or just the first line?
(looks just like a netstat dump).
Anyway, at least you now know to look at sed documentation and regexp. I'd suggest it may take you
a day to get some practice (I'm no expert with sed or regexp).
For example, if you wanted to match just a single line, e.g. the 10.1.1... line that you have, then you'd use something like:
grep -n -i"10.1.1.[0-9]*[ \t]*[0-9]*.[0-9]*.[0-9]*.[0-9]*" *
and that would check most of the first line (you could extend further if you think you really need to match further.
The example above is fairly self-explanatory.
Anything more complex, you really need to study regular expressions (I am not an expert, and I tend to
consult a book when I need to do any more complex regexp). The best reference work is "Mastering Regular Expressions"
by Freidl.

 

[knowledge_Seeker1]

Thank you for your reply, Its been a couple of hours that i am trying to know how to do it with sed by i cant seem to get this working :S
unfortunately i cant afford to spend a couple of days on this because i have a deadline to submit the results of my simulation and i really need this command :s
can anybody please help me ?

 

[sky_123]

Ok, this should work for you (I reverted to a language I'm better at than sed/regexp).
This C code does a _partial_ check, which should be sufficient to identify the structure of the paragraph (but not the entire detail).
Maybe that is sufficient.

#include <stdio.h>


FILE* f;

int
main(void)
{

  char tbuf[1000];
  int i;
  int row=0;
  int rowadd;
  int found;

  f=fopen("testfile.txt", "r");
  if (!f)
  {
  	printf("Error opening file\n");
  	return(1);
  }

  fgets(tbuf, 999, f);
  row++;
  while (!feof(f))
  {
    found=0;
    rowadd=0;
    
    printf(".");
    if (strncmp("Node:", tbuf, 5)==0)
    {
      fgets(tbuf, 999, f);
      rowadd++;
      if (strncmp("  Priority:", tbuf, 11)==0)
      {
        fgets(tbuf, 999, f);
        rowadd++;
        if (strncmp("Destination", tbuf, 11)==0)
        {
          fgets(tbuf, 999, f);
        	rowadd++;
        	if (strncmp("10.1.1.1", tbuf, 8)==0)
        	{
        	  printf("\nMatch found on line %d\n", row);
        	  found=1;
        	}
        }
      }
    }
    else
    {
    	fgets(tbuf, 999, f);
    	row++;
    }
    row=row+rowadd;
    rowadd=0;
  }
  
  fclose(f);
  return(0);
  
}

I ran this code with a test file (needs to be called testfile.txt):

the quick
brown fox
jumped
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
over the
lazy dog
Node: x Time: xs Ipv4ListRouting table
  Priority: 5 Protocol: ns3::olsr::RoutingProtocol
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

This was the output:

filecheck.exe
....
Match found on line 4
..........
Match found on line 17
........

You could play around with the source code to make it a better file inspection if this one is inaccurate.
I've attached a windows executable (worked for me on Win7) and the test file that I used.

View attachment filecheck.zip
View attachment testfile.txt