read text file position base

[Packs]

Dear Team,

I am getting text file with data. these data are in position base .

I know I have to loop the line and cut each line position base .

I have used same think in ado.net where we have to pass position and it create dataset for me .

is there any best method or library .

Please guid me

[cdbc]

Hi
Too little information...
You can use 'Copy()' to get substrings position-wise:
Param1 = source string full
Param2 = start-position (1 based)
Param3 = length of the substring you wish to extract / copy
Example:

Code: Pascal  [Select][+][-]

1. var
2.   ls: string = 'The quick brown fox, jumped over the lazy dog';
3.   sub: string;
4. begin
5.   sub:= copy(ls,1,20);
6.   writeln('copy 1..20 = ',sub); { prints "The quick brown fox," }
7.   sub:= copy(ls,21,6);
8.   writeln('copy 21..27 = ',sub); { prints "jumped" }
9. // etc.
10. end;
11.  

HTH
Regards Benny

[Bart]

Can you give an example of a text file, and what data you need to extract from it?

Bart

[Handoko]

As mentioned, we need the an example of the text file.

I have written 2 text file demos, you can download them from here:
https://wiki.freepascal.org/Portal:HowTo_Demos#File_handling

[Packs]

Code: Pascal  [Select][+][-]

1.  
2.  inward_data =  TFixedFormatDataSet
3.  
4. this is file data
5. 800015023800068002301120240000003000000027974810100022013                       FTT002027974291120240107658101000220.TIFBTT002027974291120240107658101000220.TIFFTJ002027974291120240107658101000220.TIF291120246000150000107658101000220       XXXXXXX X XXXXX                006180600000010
6.  
7.  
8.     inward_data.Close;
9.  
10.     inward_data.Schema.Append('presenting_bank=9');
11.     inward_data.Schema.Append('drawee_bank=9');
12.     inward_data.Schema.Append('bussiness_date=8');
13.     inward_data.Schema.Append('amount=13');
14.     inward_data.Schema.Append('inst_no=6');
15.     inward_data.Schema.Append('item_seq_no=10');
16.     inward_data.Schema.Append('tran_code=2');
17.     inward_data.Schema.Append('blank=23');
18.     inward_data.Schema.Append('image=120');
19.     inward_data.Schema.Append('udk=34');
20.     inward_data.Schema.Append('particular=37');
21.     inward_data.Schema.Append('account=15');
22.     inward_data.Schema.Append('blank_space=1');
23.  
24.     inward_data.FileName:=Opendlg_inward.FileName ;
25.     inward_data.Open;
26.  
27.  

it is showing wrong output . I have attached the error file too

[Packs]

it is solved

    inward_data.CodePage := 'windows-1252'; //utf-8

[cdbc]

Hi
Sorry mate, but these 2 are NOT AT ALL THE SAME!

inward_data.CodePage := 'windows-1252'; //utf-8

CP-1252 is a single-byte codepage, like CP-8859_1
Whereas UTF8 is a multi-byte codepage, i.e.: 1 codepoint = 1..4 bytes
Regards Benny

[Packs]

I have used following method it is working for me
 inward_data.CodePage := 'windows-1252';

[cdbc]

Hi
By the looks of your data, that should be correct, at a quick glance, they seem to be single-byte.
Regards Benny

[Packs]

if you don't mind can you explain me in detailed

what is codepage . why it is needed

it should be simple position base parsing .

[cdbc]

Hi
A codepage is simply a table of characters that can be represented by the 0..255 byte values of one single byte ~ /old-school/
In the DOS-days we used e.g.: CP850 a lot, then came windows and we used CP-1252 a lot, then windows switched to 'mbcs' ~ min 2 bytes per char/codepoint ~ UTF16 ~ WideString. Nowadays windows too supports UTF8.
This codepage / unicode stuff is a huge technical field, with lots of research and work going into it.
example:

Code: Text  [Select][+][-]

1. Text: Peña
2.  
3. text    sgl-byte    multi-byte
4. P       1           1
5. e       1           1
6. ñ       1 #nnn      2 #C3nn
7. a       1           1
8. ------------------------------
9. 4       4           5

In multi-byte, all the ascii chars (0..127) are the same as in single-byte.
HTH
Regards Benny

[Packs]

Thank you so much for detailed expiation 🙏🙏🙏🙏