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Reading Text files

Posted on 2008-06-19
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Last Modified: 2008-06-19
Im writing a program which reads information from numerous text files and currently I am reading all the information from the text file into an array of structs then manupilating my data from there.

I am programming an option that will allow the user to see a machine history over several months due to this I need to open and read alot of text files.  As there is alot of information I dont think the way im doing it is the best solution.

SUB-BATCH,C1.0 M2.1,16-01-08,001020005013,A: ,B: 1,C:2,D: ,ID:12,0,0,0,0,0,0,5000,0,CT:,5000,0,0,0,0,RT:,0,GT:,5000,

Shown above is an example of a record stored in my text file.  Normally I would search each file based on b and c number that the user enters.  In the example above not only would I be searching for b and c number but also for type = SUB-BATCH.  All my fields are seperated by a comma and at the end of each record is a newline character.  

What I would like to know is there anyway I can go through a text file searching for the b and c number (and type in this case) find a match and only extract that record from the file without having to read the whole file.  

Few more points - some of my text files have numerous records with the same b and c number others have only one record per machine but based on the text file I always know what position in the text file that the b and c number will occur.

Any help greatly appreciated
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Question by:lisa_mc
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3 Comments
 
LVL 53

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Infinity08 earned 300 total points
ID: 21820494
>> without having to read the whole file.  

No.

But you could speed things up a bit by only processing those lines that start with SUB-BATCH. Ie., read in the file one line at a time, and for each line, check whether it starts with "SUB-BATCH". If so, process the line (and check the b and c values). If not, just skip the line, and go on to the next.
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by:rstaveley
rstaveley earned 200 total points
ID: 21820993
If the lines are variable length and fields are at variable offsets, you will need to read them line by line.

It sounds to me like you'd do well to load these records into a relational database, with appropriate indexing for your queries.
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by:lisa_mc
ID: 21821206
Thanks guys for both your answers now I know whats possible

Cheers
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