Sponsored Content
Top Forums Shell Programming and Scripting Slow performance filtering file Post 302495680 by markhahn on Friday 11th of February 2011 12:25:45 AM
Old 02-11-2011
use the right tool

I have to admit I'm pretty turned off by this kind of shell script - spawning way too many trivial processes to perform minor processing. for instance, in perl:

Code:
#!/usr/bin/perl
use strict;
while (<>) {
    my ($date,$time,$rest) = /^(.{10}) (.{8}),(.+)$/;
    $rest = $1 if ($rest =~ /^"(.+)"$/);
    my ($prefix,$num,$type,$message) = ($rest =~ /^(...)(....)(.) (.+)$/);
    print "$date,$time,$prefix,$num,$type,$message\n" if ($type eq 'E');
}

could be down to ~3 lines with perl -n and integrating the 'E' test into the pattern match.

to me, shell is ok for command-y stuff (not processing). I turn to awk mainly for quick processing of simple, delimited tables on the commandline. for anything more than trivial (real parsing, any math), I use perl.
 

8 More Discussions You Might Find Interesting

1. Post Here to Contact Site Administrators and Moderators

Help! Slow Performance

Is the performance now very, very slow (pages take a very long time to load)? Or is it just me? Neo (6 Replies)
Discussion started by: Neo
6 Replies

2. Shell Programming and Scripting

egrep is very slow : How to improve performance

We have an egrep search in a while loop. egrep -w "$key" ${PICKUP_DIR}/new_update >> ${PICKUP_DIR}/update_record_new ${PICKUP_DIR}/new_update is 210 MB file In each iteration, the egrep on an average takes around 50-60 seconds to search. Ther'es nothing significant in the loop other... (7 Replies)
Discussion started by: hidnana
7 Replies

3. Filesystems, Disks and Memory

Slow Copy(CP) performance

Hi all We have got issues with copying a 2.6 GB file from one folder to another folder. Well, this is not the first issue we are having on the box currently, i will try to explain everything we have done from the past 2 days. We got a message 2 days back saying that our Production is 98%... (3 Replies)
Discussion started by: b_sri
3 Replies

4. UNIX for Dummies Questions & Answers

Slow copy/performance... between volumes

hi guys We are seeing weird issues on my Linux Suse 10, it has lotus 8.5 and 1 filesystem for OS and another for Lotus Database. the issue is when the Lotus service starts wait on top is very high about 25% percent and in general CPU usage is very high we found that when this happens if we... (0 Replies)
Discussion started by: kopper
0 Replies

5. Infrastructure Monitoring

99% performance wa, slow server.

There is a big problem with the server (VPS based on OpenVZ, CentOS 5, 3GB RAM). The problem is the following. The first 15-20 minutes after starting the server is operating normally, the load average is less than or about 1.0, but then begins to increase sharply% wa, then hovers around 95-99%.... (2 Replies)
Discussion started by: draiphod
2 Replies

6. Red Hat

GFS file system performance is very slow

My code Hi All, I am having redhat linux 5.3 (Tikanga) with GFS file system and its very very slow for executing ls -ls command also.Please see the below for 2minits 12 second takes. Please help me to fix the issue. $ sudo time ls -la BadFiles |wc -l 0.01user 0.26system... (3 Replies)
Discussion started by: susindram
3 Replies

7. Solaris

Solaris 11.1 Slow Network Performance

I have identical M5000 machines that are needing to transfer very large amounts of data between them. These are fully loaded machines, and I've already checked IO, memory usage, etc... I get poor network performance even when the machines are idle or copying via loopback. The 10 GB NICs are... (7 Replies)
Discussion started by: christr
7 Replies

8. Filesystems, Disks and Memory

Slow copy (cp) performance when overwriting files

I have a lot of binary files I need to copy to a folder. The folder is already filled with files of the same name. Copying on top of the old files takes MUCH longer than if I were to delete the old files then copy the new files to the now-empty folder. This result is specific to one system -... (3 Replies)
Discussion started by: ces55
3 Replies
funtbl(1)							SAORD Documentation							 funtbl(1)

NAME
funtbl - extract a table from Funtools ASCII output SYNOPSIS
funtable [-c cols] [-h] [-n table] [-p prog] [-s sep] <iname> DESCRIPTION
[NB: This program has been deprecated in favor of the ASCII text processing support in funtools. You can now perform fundisp on funtools ASCII output files (specifying the table using bracket notation) to extract tables and columns.] The funtbl script extracts a specified table (without the header and comments) from a funtools ASCII output file and writes the result to the standard output. The first non-switch argument is the ASCII input file name (i.e. the saved output from funcnts, fundisp, funhist, etc.). If no filename is specified, stdin is read. The -n switch specifies which table (starting from 1) to extract. The default is to extract the first table. The -c switch is a space-delimited list of column numbers to output, e.g. -c "1 3 5" will extract the first three odd-numbered columns. The default is to extract all columns. The -s switch specifies the separator string to put between columns. The default is a single space. The -h switch specifies that column names should be added in a header line before the data is output. With- out the switch, no header is prepended. The -p program switch allows you to specify an awk-like program to run instead of the default (which is host-specific and is determined at build time). The -T switch will output the data in rdb format (i.e., with a 2-row header of column names and dashes, and with data columns separated by tabs). The -help switch will print out a message describing program usage. For example, consider the output from the following funcnts command: [sh] funcnts -sr snr.ev "ann 512 512 0 9 n=3" # source # data file: /proj/rd/data/snr.ev # arcsec/pixel: 8 # background # constant value: 0.000000 # column units # area: arcsec**2 # surf_bri: cnts/arcsec**2 # surf_err: cnts/arcsec**2 # summed background-subtracted results upto net_counts error background berror area surf_bri surf_err ---- ------------ --------- ------------ --------- --------- --------- --------- 1 147.000 12.124 0.000 0.000 1600.00 0.092 0.008 2 625.000 25.000 0.000 0.000 6976.00 0.090 0.004 3 1442.000 37.974 0.000 0.000 15936.00 0.090 0.002 # background-subtracted results reg net_counts error background berror area surf_bri surf_err ---- ------------ --------- ------------ --------- --------- --------- --------- 1 147.000 12.124 0.000 0.000 1600.00 0.092 0.008 2 478.000 21.863 0.000 0.000 5376.00 0.089 0.004 3 817.000 28.583 0.000 0.000 8960.00 0.091 0.003 # the following source and background components were used: source_region(s) ---------------- ann 512 512 0 9 n=3 reg counts pixels sumcnts sumpix ---- ------------ --------- ------------ --------- 1 147.000 25 147.000 25 2 478.000 84 625.000 109 3 817.000 140 1442.000 249 There are four tables in this output. To extract the last one, you can execute: [sh] funcnts -s snr.ev "ann 512 512 0 9 n=3" | funtbl -n 4 1 147.000 25 147.000 25 2 478.000 84 625.000 109 3 817.000 140 1442.000 249 Note that the output has been re-formatted so that only a single space separates each column, with no extraneous header or comment informa- tion. To extract only columns 1,2, and 4 from the last example (but with a header prepended and tabs between columns), you can execute: [sh] funcnts -s snr.ev "ann 512 512 0 9 n=3" | funtbl -c "1 2 4" -h -n 4 -s " " #reg counts sumcnts 1 147.000 147.000 2 478.000 625.000 3 817.000 1442.000 Of course, if the output has previously been saved in a file named foo.out, the same result can be obtained by executing: [sh] funtbl -c "1 2 4" -h -n 4 -s " " foo.out #reg counts sumcnts 1 147.000 147.000 2 478.000 625.000 3 817.000 1442.000 SEE ALSO
See funtools(7) for a list of Funtools help pages version 1.4.2 January 2, 2008 funtbl(1)
All times are GMT -4. The time now is 08:22 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy