Good day,

I need help from you.

I have to split and create output files by every 30.000 recordings.
Example ,

Input file has 150.000 (transaction.txt) recordings of bank accounts transactions.
The C code has to split this file and create output files by 30.000 records each from input file.
(transaction1.txt, transaction2.txt, transaction3.txt and etc.).The transaction.txt (150.000 recordings) has to be split on many files with 30.000 recordings.
So , does anybody know how to do this?
How C code will look like for this operation?

Thank you very much.

Please see how Account.txt file looks.

07004262890147655236      74105616281002275393260000000001007000000002000428000000002000428LHZB ATMH0418 - Limbaz   Limbazi      LV 6011          1009N3049252 2   6282
0701            000000 00002                                                    5904180        ATMH0418000000000000  000000      00                          000000000  
07004389380039629638      74105616281002275394193000000001007000000015000428000000015000428LHZB ATMH0401 - Elizab   Riga         LV 6011          1009N2084002 2   6282
0701            000000 00002                                                    5904016        ATMH0401000000000000  000000      00                          000000000  
07004262890148616575      74105616281002275257663000000001007000000002000428000000002000428LHZB ATMH0422 - Aizkra   Aizkraukle   LV 6011          1009N2201432 2   6282
0701            000000 00002                                                    5904222        ATMH0422000000000000  000000      00                          000000000  
07004262890146321046      74105616281002275252417000000001007000000010000428000000010000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N3462742 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004262890146321046      74105616281002275252409000000001007000000002000428000000002000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N3369872 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004262890144868220      74105616281002275252391000000001007000000002000428000000002000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N3123242 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004262890147233141      74105616281002275252342000000001007000000001000428000000001000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N2373252 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004262890146395032      74105616281002275252300000000001007000000001000428000000001000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N2273262 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004262890146802094      74105616281002275252292000000001007000000005000428000000005000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N2232802 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004262890144868220      74105616281002275252326000000001007000000003000428000000003000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N2325232 2   6282
0701            000000 00002                                                    5904339        ATMH0433000000000000  000000      00                          000000000  
07004389380039446967      74105616281002275252334000000001007000000005000428000000005000428LHZB ATMH0433 - Kudras   Riga         LV 6011          1009N2355882 2   6282
0701            000000 00002                                                    

The records appear to be fixed length.  Is that right?

If they are fixed length, then the easiest and most efficient way would probably to read record_size * 30000 bytes & write that to a file, then continue do that until you reach the end of the input file.

$ split --help
Usage: split [OPTION] [INPUT [PREFIX]]
Output fixed-size pieces of INPUT to PREFIXaa, PREFIXab, ...; default
size is 1000 lines, and default PREFIX is `x'.  With no INPUT, or when INPUT
is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.
  -a, --suffix-length=N   use suffixes of length N (default 2)
  -b, --bytes=SIZE        put SIZE bytes per output file
  -C, --line-bytes=SIZE   put at most SIZE bytes of lines per output file
  -d, --numeric-suffixes  use numeric suffixes instead of alphabetic
  -l, --lines=NUMBER      put NUMBER lines per output file
      --verbose           print a diagnostic to standard error just
                            before each output file is opened
      --help     display this help and exit
      --version  output version information and exit

SIZE may have a multiplier suffix: b for 512, k for 1K, m for 1 Meg.

Report bugs to <bug-coreutils@gnu.org>.

But if it's your homework to do it in C, then start with fgets() and fputs().

--

Thanks for your answers.