Replace text in a .txt file from another .txt file

Question

I want to automate a process that I do manually right now. I currently compare two .txt documents (we will call them "D1" and "D2") and create a third (call it "D3") that is a combination of the other two. What I need to do is find a certain string in "D1" and find a similar/same string in "D2". Once there is a match, I need to replace the string in "D1" with the following string that matched "D2" and put it in "D3" as a master file. This sounds a bit confusing so here is what I would like it to look like:

The .txt file format for "D1" is as follows:

    1       0010  12345              DEF, DEF-0320            
    1       0020  ABC-00010G         ABC-A,1xx,10%,x1x,0603   
    1       0020A ABC-00010G         ABC-A,1xx,10%,x1x,0603   
    1       0030A ABC-00127G         ABC,4.7xx,10%,x1x,0805

The .txt file format for "D2" is as follows:

    10 BARE PCB
    20 T C40, C3112
    B C5, C45, C48
    30 B C25

I want to compare both "D1" and "D2" and find the values '0010', '0020', '0020A', '0030A' from "D1" and the values '10', '20', '30' from "D2". If (when) there is a match between the two sets of numbers (ie, '0010' and '10') I would like to format a new document, "D3", as follows:

    1       AAAA BCD  142717             DEF, DEF-0320                 T
    1       C40       ABC-00010G         ABC-A,1xx,10%,x1x,0603        T
    1       C3112     ABC-00010G         ABC-A,1xx,10%,x1x,0603        T
    1       C5        ABC-00010G         ABC-A,1xx,20%,x1x,0603        B
    1       C45       ABC-00010G         ABC-A,1xx,20%,x1x,0603        B
    1       C48       ABC-00010G         ABC-A,1xx,20%,x1x,0603        B
    1       C25       ABC-00127G         ABC,4.7xx,100%,x1x,0805       B

The 'T/B' is assigned based on whether or not there is an 'A' following the second number in "D1". 'T' is assigned if there is just a number, 'B' is assigned if there is an 'A'. Also, there are more lines in the "D3" .txt document because of the ',' seperating the different values (ie, for '20', there is 'C40' and 'C3112'). For every ',' in "D2" there needs to be a new line in "D3" that has the same following format as the line above it.

What's the question? I'm only seeing a problem statement here... — Merlyn Morgan-Graham, Jun 23 '11 at 19:05
I am not looking for written code but rather help on how to go about this. I am pretty new to C# and would like to understand how to properly compare two text files and replace matches in the two files with other text from the second file and output it into the third. So my question is, what is the best way to go about reading "D1" and "D2" and comparing the two for similar strings and than proceeding to replace the text in "D1"? — theNoobGuy, Jun 23 '11 at 19:37

score 3 · Accepted Answer · edited May 23 '17 at 12:13

Colton wrote

So my question is, what is the best way to go about reading "D1" and "D2" and comparing the two for similar strings and than proceeding to replace the text in "D1"?

Here's a way (there is no best way, at least not one where everyone agrees with one another):

read both files line by line [?]
split each line on their white spaces [?]
for both files, create a 2 dimensional array [?]
compare the appropriate columns from your 2 dimensional arrays to each other and check if one contains the other [?]
write something back to a 3rd file [?]

Replace text in a .txt file from another .txt file

1 Answers1