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How to compare 2 files and update one?

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Top Forums Shell Programming and Scripting How to compare 2 files and update one?
# 1  
Old 08-15-2013
Linux How to compare 2 files and update one?
Hi,

I have got 2 files which i need to compare and append based on the below conditions.

file 1:

File 1 has data in the following format

Code:
4300 2356
C234 5689
5500 2345

File 2 has data in the same fomat

Code:
4300 49
5555 12345

Now i need to compare the first 4 bytes in each line from file2 and see if it exists on file1, and if they match ( they may be present in any position), i need to append the values present in pos6 onwards in sorted order

For example, for the number 4300 the value should come as

4300 234569

and if the number in the 1st 4 bytes of file 2 is not found in file 1 , i need to append the whole line to file 1.

How can this be done......need help....anyone plzzz SmilieSmilieSmilieSmilie
Last edited by jim mcnamara; 08-15-2013 at 05:34 PM..
# 2  
Old 08-15-2013
Try this as a starting point; the sort of $2 you need to compose yourself:
Code:
sort file1 file2 |
awk     '$1 == SV1              {SV2=SV2 $2;next}
         NR>1 && $1 != SV1      {print SV1, SV2}
                                {SV1=$1;SV2=$2}
         END                    {print SV1,SV2} 
        '

# 3  
Old 08-15-2013
try:
Code:
awk '
function srt(ir, ln) {
   do {
      upd = 0;
      for(i=1; i < ln; i++) {
         if ( ir[i] > ir[i+1] ) {
            t = ir[i];
            ir[i] = ir[i+1];
            ir[i+1] = t;
            upd = 1;
         }
      }
   } while ( upd == 1 )
}
FNR==NR {a[$1]=$2; next}
a[$1] {
   $2=a[$1] $2;
   for (i in ar) delete ar[i];
   al=length($2);
   for (i=1; i<=al; i++) ar[i]=substr($2,i,1);
   srt(ar, al); s="";
   for (i=1; i<=length($2); i++) s=s ar[i];
   $2=s;
}
1
' file2 file1

for GNU style awks try:
Code:
awk '
FNR==NR {a[$1]=$2; next}
a[$1] {
   $2=a[$1] $2;
   split($2,ar, "");
   asort(ar); s="";
   for (i=1; i<=length($2); i++) s=s ar[i];
   $2=s;
}
1
' file2 file1

Last edited by rdrtx1; 08-15-2013 at 07:07 PM..
# 4  
Old 08-21-2013
can you please explain the above code???
The code given by Rudy is good....but i need a single code which will do the sorting of data col 6 onwards too......SmilieSmilie
# 5  
Old 08-21-2013
Before the print statements, you can n=split (SV2, TMP, "");, call a sort function (like the one by rdrtx1) for TMP, and then, instead SV2, print TMP[i] in a loop 1..n.
Last edited by RudiC; 08-21-2013 at 04:10 PM.. Reason: typo
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