If I recall correctly, cygwin and win7 not -64 is 32 bit, so 'a' may get too big for the address space of the awk process. Depending on ram size, it might eventually thrash a bit. The awk solution, a hash map, does not support parallism.
The classic, robust solution is 'sort -u <file_set>' but tends to be slower. You can parallelize the sort with a command of the form:
where the nicer ksh or bash makes named pipes of the '<(...)' that run concurrently. I like twice the core count <(sort)'s, assuming 50% i/o delay. The final pass of the <(sort)'s feeds the sort -m merge parent.
ETL programs like Ab Initio know how to tell parallel processes to split up big files and process each part separately, even when the files are linefeed delimited (they all agree to search up (or down) for the dividing linefeed closest to N bytes down file). Does anyone know of a utility that can split a file this way (without reading it sequentially)? 'GNU parallel?'
I have a file which consists of 1000 entries. Out of 1000 entries i have 500 Duplicate Entires. I want to remove the first Duplicate Entry (i,e entire Line) in the File.
The example of the File is shown below:
8244100010143276|MARISOL CARO||MORALES|HSD768|CARR 430 KM 1.7 ... (1 Reply)
Hi,
My awk program is failing. I figured out using command
od -c filename
that the last line of the file doesnt end with a new line character.
Mine is an automated process because of this data is missing.
How do i handle this?
I want to append new line character at the end of last... (2 Replies)
i have the long file more than one ns and www and mx in the line like .
i need the first ns record and first www and first mx from line .
the records are seperated with tthe ; i am try ing in awk scripting not getiing the solution.
... (4 Replies)
Hi Sorry to multipost. I am opening the new thread because the earlier threads head was misleading to my current doubt.
and i am stuck.
list=`cat /u/Test/programs`;
psg "ServTest" | awk -v listawk=$list '{
cmd_name=($5 ~ /^/)? $9:$8
for(pgmname in listawk)
... (6 Replies)
I have an extremely large csv file that I need to search the second field, and upon matches update the last field...
I can pull the line with awk.. but apparently you cant use awk to directly update the file? So im curious if I can use sed to do this... The good news is the field I want to... (5 Replies)
Folks ,
i want to read a csv file line by line till the end of file and filter the text in the line and append everything into a variable.
csv file format is :-
trousers:shirts,price,50
jeans:tshirts,rate,60
pants:blazer,costprice,40
etc
i want to read the first line and get... (6 Replies)
I have several hundreds of tiny files which need to be concatenated into one single line and all those in a single file. Some files have several blank lines. Tried to use this script but failed on it.
awk 'END { print r } r && !/^/ { print FILENAME, r; r = "" }{ r = r ? r $0 : $0 }' *.txt... (8 Replies)
I'm looking to remove duplicate rows from a CSV file with a twist.
The first row is a header.
There are 31 columns. I want to remove duplicates when the first 29 rows are identical ignoring row 30 and 31 BUT the duplicate that is kept should have the shortest total character length in rows 30... (6 Replies)
Hi all,
I've got a file that has 12 fields. I've merged 2 files and there will be some duplicates in the following:
FILE:
1. ABC, 12345, TEST1, BILLING, GV, 20/10/2012, C, 8, 100, AA, TT, 100
2. ABC, 12345, TEST1, BILLING, GV, 20/10/2012, C, 8, 100, AA, TT, (EMPTY)
3. CDC, 54321, TEST3,... (4 Replies)
My file (the output of an experiment) starts off looking like this,
_____________________________________________________________
Subjects incorporated to date: 001
Data file started on machine PKSHS260-05CP
**********************************************************************
Subject 1,... (9 Replies)
Discussion started by: samonl
9 Replies
LEARN ABOUT REDHAT
csv
csv(n) CSV processing csv(n)
NAME
csv - Procedures to handle CSV data.
SYNOPSIS
package require Tcl 8.3
package require csv ?0.3?
::csv::join values {sepChar ,}
::csv::joinlist values {sepChar ,}
::csv::read2matrix chan m {sepChar ,} {expand none}
::csv::read2queue chan q {sepChar ,}
::csv::report cmd matrix ?chan?
::csv::split line {sepChar ,}
::csv::split2matrix m line {sepChar ,} {expand none}
::csv::split2queue q line {sepChar ,}
::csv::writematrix m chan {sepChar ,}
::csv::writequeue q chan {sepChar ,}
DESCRIPTION
The csv package provides commands to manipulate information in CSV FORMAT (CSV = Comma Separated Values).
COMMANDS
The following commands are available:
::csv::join values {sepChar ,}
Takes a list of values and returns a string in CSV format containing these values. The separator character can be defined by the
caller, but this is optional. The default is ",".
::csv::joinlist values {sepChar ,}
Takes a list of lists of values and returns a string in CSV format containing these values. The separator character can be defined
by the caller, but this is optional. The default is ",". Each element of the outer list is considered a record, these are separated
by newlines in the result. The elements of each record are formatted as usual (via ::csv::join).
::csv::read2matrix chan m {sepChar ,} {expand none}
A wrapper around ::csv::split2matrix (see below) reading CSV-formatted lines from the specified channel (until EOF) and adding them
to the given matrix. For an explanation of the expand argument see ::csv::split2matrix.
::csv::read2queue chan q {sepChar ,}
A wrapper around ::csv::split2queue (see below) reading CSV-formatted lines from the specified channel (until EOF) and adding them
to the given queue.
::csv::report cmd matrix ?chan?
A report command which can be used by the matrix methods format 2string and format 2chan. For the latter this command delegates the
work to ::csv::writematrix. cmd is expected to be either printmatrix or printmatrix2channel. The channel argument, chan, has to be
present for the latter and must not be present for the first.
::csv::split line {sepChar ,}
converts a line in CSV format into a list of the values contained in the line. The character used to separate the values from each
other can be defined by the caller, via sepChar, but this is optional. The default is ",".
::csv::split2matrix m line {sepChar ,} {expand none}
The same as ::csv::split, but appends the resulting list as a new row to the matrix m, using the method add row. The expansion mode
specified via expand determines how the command handles a matrix with less columns than contained in line. The allowed modes are:
none This is the default mode. In this mode it is the responsibility of the caller to ensure that the matrix has enough columns to
contain the full line. If there are not enough columns the list of values is silently truncated at the end to fit.
empty In this mode the command expands an empty matrix to hold all columns of the specified line, but goes no further. The overall
effect is that the first of a series of lines determines the number of columns in the matrix and all following lines are
truncated to that size, as if mode none was set.
auto In this mode the command expands the matrix as needed to hold all columns contained in line. The overall effect is that after
adding a series of lines the matrix will have enough columns to hold all columns of the longest line encountered so far.
::csv::split2queue q line {sepChar ,}
The same as ::csv::split, but appending the resulting list as a single item to the queue q, using the method put.
::csv::writematrix m chan {sepChar ,}
A wrapper around ::csv::join taking all rows in the matrix m and writing them CSV formatted into the channel chan.
::csv::writequeue q chan {sepChar ,}
A wrapper around ::csv::join taking all items in the queue q (assumes that they are lists) and writing them CSV formatted into the
channel chan.
FORMAT
Each record of a csv file (comma-separated values, as exported e.g. by Excel) is a set of ASCII values separated by ",". For other lan-
guages it may be ";" however, although this is not important for this case (The functions provided here allow any separator character).
If a value contains itself the separator ",", then it (the value) is put between "".
If a value contains ", it is replaced by "".
EXAMPLE
The record
123,"123,521.2","Mary says ""Hello, I am Mary"""
is parsed as follows:
a) 123
b) 123,521.2
c) Mary says "Hello, I am Mary"
SEE ALSO
matrix, queue
KEYWORDS
csv, matrix, queue, package, tcllib
csv 0.3 csv(n)