update a file by key

ynixon · #1 (**permalink**) 03-25-2007

Hi,
I am trying to update a MASTER file by a NEW file which may contain fewer records.
The update should use a key (2 first fields), here is a senario:
MASTER:
a;b;0
a;c;0
a;d;0

NEW:
a;c;1

the result should be:
a;b;0
a;c;1
a;d;0

can you recommend me a way to do it?

10x
Y.N.

ghostdog74 · #2 (**permalink**) 03-25-2007

if you have Python, here's an alternative:

Code:

#!/usr/bin/python
new = open("new").readlines()
fi = open("file").readlines()
for li in fi:
    li = li.strip().split(";")
    for li2 in new:
        li2 = li2.strip().split(";")
        if li2[0] == li[0] and li2[1] == li[1]:
            print ';'.join(li2)
        else:
            print ';'.join(li)

dennis.jacob · #3 (**permalink**) 03-26-2007

Plz give a try on this...

Code:

awk -F";" 'BEGIN {OFS=";"; i=1; while((getline line < "NEW")>0) arr[i++]=line; }  { for(j=1;j<i;j++) { split(arr[j],temp,";"); if (($1==temp[1])&&($2==temp[2])) {$3=temp[3];} }print; }' MASTER

ynixon · #4 (**permalink**) 03-26-2007

this is working fast

thank you

ynixon · #5 (**permalink**) 03-27-2007

Quote:

Originally Posted by jacoden

Plz give a try on this...

Code:

awk -F";" 'BEGIN {OFS=";"; i=1; while((getline line < "NEW")>0) arr[i++]=line; }  { for(j=1;j<i;j++) { split(arr[j],temp,";"); if (($1==temp[1])&&($2==temp[2])) {$3=temp[3];} }print; }' MASTER

I forgot to mention that I also need to add to the result new records from NEW that does not exist in MASTER.
for example:

MASTER:
a;b;0
a;c;0
a;d;0

NEW:
a;c;1
a;e;2

the result should be:
a;b;0
a;c;1
a;d;0
a;e;2

anbu23 · #6 (**permalink**) 03-27-2007

Quote:

Originally Posted by ynixon

I forgot to mention that I also need to add to the result new records from NEW that does not exist in MASTER.
for example:

MASTER:
a;b;0
a;c;0
a;d;0

NEW:
a;c;1
a;e;2

the result should be:
a;b;0
a;c;1
a;d;0
a;e;2

Code:

awk -F";" ' BEGIN {OFS=";"; while( getline < "NEW" ) arr[$1";"$2]=$3; }
{  if( arr[$1";"$2] !~ /^ *$/ ) { $3=arr[$1";"$2]; print; delete arr[$1";"$2] } 
   else print 
}
END { 
for ( key in arr ) {
if( arr[key] !~ /^ *$/ ) { print key";"arr[key] } 
} } ' MASTER

ynixon · #7 (**permalink**) 03-27-2007

It is even working faster

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