Look for Certain Number in a Field and Retrieve Line

Keywords: 	  LAFFDB binary indexing

Question:

Presently, I have a tab delimited file (Security log dumpel file) that I look for a curtain number in the 5th field (event), then retrieve the entire line. Now, I would like to load this file into a memory buffer, search for this event (this 3 digit number can also exist in other fields, so I need to be able to search in the 5th field only) and then retrieve the entire line into a variable. Any suggestion?

Answer:

Well, I would SUGGEST taking a look at the LAFFDB extender. What you really have there is a Light ascii flat file database. that's exactly what the extender is made for.

You'll start by opening the database with DBOPEN().
Next, set up some variables and use DBBINDCOL() to link them to the fields in the records of the database.
Then, use DBFINDRECORD() to search for the ones you want. you can set up a while loop to "wind" through the matching records pretty easily.
Each time you find a match, just use DBGETENTIRERECORD() and the variables will be filled with the values you want, then you can do your actual work.

Example of winding loop - dbfindrecord returns a -1 when there's no more matches

while @true
	linenumber = dbfindrecord(...search criteria...)
	if linenumber = -1 then break
	dbgetentirerecord(...details of the record...)
	gosub Deal_with_the_record
endwhile

Here is a more useful example:

Addextender("LAFFD34i.DLL")

db_fn        = "Security log dump file.log"
db_create    = 0 ; file should exist
db_model     = 2 ; traditional
db_cols      = 0 ; use the number of columns in the first line of the file
db_format    = 0 ; delimiter based
db_delimiter = @tab
db_options   = "" ; don't bother

hnd_db = dbopen(db_fn,db_create,db_model,db_cols,db_format,db_delimit,db_option)

db_colcount = dbgetcolumncount(hnd_db)

for a = 1 to db_colcount
        
        dbbindcol(hnd_db,a,VAR%a%)
        
next

search_flags = 1 + 4          ; use and return fixed record nums (note that fixed record nums are 1 based), and search forward
search_col   = 5              ; this is the column you wanted to skim
search_value = curtain_number ; this is what you wanted to search for
search_case  = 0              ; not case sensitive
search_start = 0              ; start at zero to actually search record #1
get_flags    = 1              ; get a fixed record num (needs to match search flag)

linenumber = search_start ; need to init the variable
while @true
        
        linenumber = dbfindrecord(hnd_db,linenumber,search_flags,search_col,search_value,search_case)) ;returns -1 if no more matches
        if linenumber < 0 then break ; breaks on done searching OR error (because error is -42424242)
        dbgetentirerecord(hnd_db,linenumber,get_flags)
        gosub Deal_with_the_record
        
endwhile

dbclose(hnd_db)

exit


;---------------------------------------------------------------------------------------------------------
:Deal_with_the_record
        
        ; here is where you will do whatever you want.. 
        ; the variables will be named var1, var2, var3, var4... etc
        ; this routine will run once for each matching line in your file
        ; have at it...
        
return
;---------------------------------------------------------------------------------------------------------

Article ID:   W15056

File Created: 2002:09:05:13:49:22

Last Updated: 2002:09:05:13:49:22

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Look for Certain Number in a Field and Retrieve Line

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