perl text file processing using hash Post: 302492605

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Top Forums UNIX for Advanced & Expert Users perl text file processing using hash Post 302492605 by drewk on Tuesday 1st of February 2011 02:03:31 AM

02-01-2011

Registered User

It is not a given that Perl will be any faster than Awk. In most cases it won't be.

Here is a code snippet that will get you started with multi-line records from a file:

Code:

#!/usr/bin/env perl

$i=0;
$throw_away=<DATA>;   # read the first record delim...
while (defined($record=<DATA>)) {
    if ($record !~ /recordstart/) {
        $record .= <DATA>; 
        redo unless eof(DATA);
    }
    $record =~ s/^recordstart\Z//m;
    # now you have the full record...
    print "====record $i:\n$record\n";
    $i++;
}
    
__DATA__
recordstart
val1               1
val2               2
val3               4
recordstart
val1               5
val2               6
val3               1
val4               1
recordstart
val1               1 
val2               3
val3               6

An alternate is to use the Perl record separator to help you:

Code:

{ 
    local $/="recordstart\n";
    $throw_away=<DATA>;
    $i=0;
    while ($record=<DATA>) {
        chomp $record;
        $i++;
        # now you have the individual records:
        print "record $i:\n$record";
    }
}

Last edited by drewk; 02-01-2011 at 05:45 AM..

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LEARN ABOUT DEBIAN

px_put_recordn

PX_PUT_RECORDN(3)					     Library Functions Manual						 PX_PUT_RECORDN(3)

NAME

       PX_put_recordn -- Stores record in Paradox file at certain position

SYNOPSIS

       #include <paradox.h>

       int PX_put_recordn(pxdoc_t *pxdoc, char *data, int recpos)

DESCRIPTION

       Stores  a  record  in the buffer data into a Paradox file at the given position recpos.	The first position has number 0. The function will
       determine the data block for this record. If the position is after the last data block, then as many as needed empty data  blocks  will	be
       added.  If the position is in the middle of a data block and there is no record right before the position, then the position will be recal-
       culated to make sure the new record will be stored in the first free slot of the datablock. For example, if a datablock contains H  records
       and  the first call of PX_put_recordn wants to store a record at postion 11, then this will be corrected to position H. PX_put_recordn will
       also add an empty data block and store the record as the first record of the second data block.	Storing a second  record  at  position	11
       again, will be executed without any position change.

       data  must  be constructed with PX_put_data_xxx(3) functions before. It is of the same structure as the record returned by PX_get_record(3)
       and PX_get_record2(3).

RETURN VALUE

       Returns the record position on success and -1 on failure. The first position has number 0.

SEE ALSO

       PX_get_record(3), PX_get_record2(3), PX_put_record(3),  PX_put_data_byte(3),  PX_put_data_short(3),  PX_put_data_long(3),  PX_put_data_dou-
       ble(3), PX_put_data_alpha(3)

AUTHOR

       This manual page was written by Uwe Steinmann uwe@steinmann.cx.

																 PX_PUT_RECORDN(3)