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Shell script for searching a record,copy to a file and then delete it


 
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# 1  
Old 04-19-2010
Shell script for searching a record,copy to a file and then delete it

Hi,

I have a requirement in hand:

I have a file with millions of records say file 1.I have another file, say file 2 which has 2000 records in it. The requirement is to read file2 , and remove the read record from file 1 and move i to a seperate file, file 3.
For eg: Read file 2, get the first record (eg: record id as 200) , read file 1, search for record id 200 and copy it to file 3, remove 200 from file 1.

Can some one help me with a flexible shell script which acheives the same faster. I tried using compare command but its taking a lot of time.Smilie

Any help would be much appreciated..Smilie
# 2  
Old 04-19-2010
What you have tried for your requirement?

Give me your input files and output file with some sample data.
# 3  
Old 04-19-2010
I tried with basic grep -x,-f,-v and appended to file 3. Just wanted to know if there is any better approach. I am attaching a sample of the data below:

file 1:
Code:
"T25","Insufficient Consumption Data to Calculate AQ","BUS",242900,139588342,2148,
"T25","Insufficient Consumption Data to Calculate AQ","SCP",1089204310,159690484,10813,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",269707,36302598,20716,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",1089211307,36203698,593,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",1089218400,36203538,8737,
"T25","Insufficient Consumption Data to Calculate AQ","SOP",1089224204,178221566,551,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",272909,173561749,7875,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",1089227300,36205098,6863,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",298108,36650298,311,
"T25","Insufficient Consumption Data to Calculate AQ","TCG",1089229708,106656758,4970,

file 2:
Code:
152708
218005
242900
243610
269707
272909
298108

Hope this helps!!

Last edited by Franklin52; 04-19-2010 at 09:34 AM.. Reason: Please use code tags!
# 4  
Old 04-19-2010
If you have given your expected output, it would be good.
Ok, anyway, check whether the following helps.


Code:
grep -f file2 file1
"T25","Insufficient Consumption Data to Calculate AQ","BUS",242900,139588342,2148,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",269707,36302598,20716,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",272909,173561749,7875,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",298108,36650298,311,

Move the matching to file3 as you asked for.

Code:
grep -vf file2 file1
"T25","Insufficient Consumption Data to Calculate AQ","SCP",1089204310,159690484,10813,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",1089211307,36203698,593,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",1089218400,36203538,8737,
"T25","Insufficient Consumption Data to Calculate AQ","SOP",1089224204,178221566,551,
"T25","Insufficient Consumption Data to Calculate AQ","BUS",1089227300,36205098,6863,
"T25","Insufficient Consumption Data to Calculate AQ","TCG",1089229708,106656758,4970,

It displays only the record which is not there in the file2. So redirect it to file4, which you asked for.
# 5  
Old 04-19-2010
Thts excellent mate..Looks like it will work. I tried with a sample file.Only doubt is on the turn around time to deal with millions of records..lemme chk it out.. Thnx for this again!!
# 6  
Old 06-16-2010
Hi,I have been using the resolution you had given last time but it doesnt seem to work with huge files. I wil explain.As in similar lines given in example above,in the real time scenario that i havefile 1 has 30K recordsfile 2 has 25 lac recordsRequirement is: Read file 1 and copy all occurances of the record in file2 to a new file,say file3.When i use grep -f file1 file2 > file 3,file 3 is having the records required along with many unwanted records in file2 and i have to delete the unwanted records in file3. Considering the huge count,its becoming tedious. Any work around to ensure that only desired records in file1 are copied to file3 from file 2??

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