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error messages

Linux / Unix Find Command: Avoid Permission Denied Messages

When I type find . -type d -name "foo" command I get Permission denied error messages. How do I exclude all "permission denied: messages from the find command under Linux or Unix like operating systems?
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Nginx Block And Deny IP Address OR Network Subnets

How do I block or deny access based on the host name or IP address of the client visiting website under nginx web server?
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PHP: Stop Notice and Variable Warnings in Error Log Files

I'm using PHP error logging in place of error displaying on production web sites. However, I do not want to see error messages about the use of uninitialized variables. I'd like to see all critical errors, except for notices and coding standards warnings. How do I disable error messages?
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FreeBSD Apache Jail: Connection refused: connect to listener on Error and Solution

Q. I'm running Apache 2 server under FreeBSD jail. However, I see lots of warning error messages in /var/log/httpd-error.log as follows:

[Sat Sep 20 20:47:09 2008] [warn] (61)Connection refused: connect to listener on
[Sat Sep 20 20:47:10 2008] [warn] (61)Connection refused: connect to listener on
[Sat Sep 20 20:47:11 2008] [warn] (61)Connection refused: connect to listener on

How do stop all these warning messages flooding my Apache log files?
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ICMP IP Network Scanning / Probing using a Shell Commands

Q. How do I check security of my network by running ICMP IP Network Scanning under FreeBSD / Linux? How do I subnet broadcast addresses? All I wanted to see if my firewall is working or not.

A. Internet Control Message Protocol (ICMP) one of the core protocols of the Internet protocol suite. It is chiefly used by networked computers' operating systems to send error messages—indicating, for instance, that a requested service is not available or that a host or router could not be reached.

ICMP IP Network Scanning with nmap tool

You can use regular open source tool called nmap. Type the following command to run ICMP IP Scan:
$ nmap -sP -PI

Starting Nmap 4.20 ( http://insecure.org ) at 2008-01-29 23:40 IST
Host appears to be up.
MAC Address: 00:18:39:6A:C6:8B (Cisco-Linksys)
Host appears to be up.
Nmap finished: 256 IP addresses (2 hosts up) scanned in 5.746 seconds


  • -sP : This option tells Nmap to only perform a ping scan (host discovery), then print out the available hosts that responded to the scan. This is also known as ping scan.
  • -PI : This open tells Nmap that we are sending ICMP echo requests

Linux LILO boot procedure freezes with LI characters (Lilo boot loader LI error)

Q. My Linux system says LI while booting system and then boots procedure freezes or halts. How do I solve this problem?

A. LILO is a generic boot loader for Linux. This error means few things. LI characters indicate that LILO is having problems. It cannot boot the system.

a) Goto BIOS and set LBA mode for hard disk and reinstall Linux

b) Make sure /boot partition created below the 1023rd cylinder on the hard drive, if not repartition and reinstall Linux

c) See this page for more information.