hosts HowTo - Linux / Unix Q & A from nixCraft

Bash Shell: Check File Exists or Not

last updated April 20, 2012 in BASH Shell

How do I test existence of a text file in bash running under Unix like operating systems?

How To Use cat Command In Linux / UNIX

last updated January 11, 2018 in Linux, UNIX

How do I use cat command in Linux? How do I use cat command in UNIX? How can I use cat command in UNIX or Linux shell scripts?

Samba Restrict IPC$ ( list of shared resources )

last updated April 20, 2009 in CentOS, Debian / Ubuntu, Linux, RedHat and Friends, Samba (SMB/CIFS), Security, Ubuntu Linux, Windows

The IPC$ share allows users to anonymously fetch a list of shared resources from a server. It can be used as a point of attack into a system. How do I disable or limit IPC$ under Samba to certain subnet such as 10.0.0.0/8?

UNIX / Linux: Explain The Nine Permissions Bits On Files

last updated February 24, 2010 in Commands, Linux, UNIX

Can you completely explain the nine permissions bits on UNIX or Linux files?

psql: FATAL: Ident authentication failed for user "username" Error and Solution

last updated August 19, 2008 in CentOS, Linux, Linux / UNIX File Formats, PostgreSQL, RedHat and Friends, Troubleshooting, UNIX

Q. I’ve installed Postgresql under Red Hat Enterprise Linux 5.x server. I’ve created username / password and database. But when I try to connect it via PHP or psql using following syntax:

psql -d myDb -U username -W

It gives me an error that read as follows:

psql: FATAL: Ident authentication failed for user “username”

How do I fix this error?

Display Apache Server Status with mod_status

last updated October 7, 2008 in Apache, CentOS, Debian / Ubuntu, Hardware, Networking, OpenBSD, RedHat and Friends, Security, Solaris-Unix, Troubleshooting, Ubuntu Linux, Windows

How do I display Apache server status such as current server activity and performance under Red Hat Enterprise Linux?

What Would Cause a Lot of ARP Broadcasts From One System / Machine

last updated March 27, 2008 in Linux, Networking, Troubleshooting, UNIX, Windows

Q. I’m experiencing decreased network performance due to ARP broadcasts coming from one system. What would cause a lot of ARP broadcasts from one server / computer?
Continue reading “What Would Cause a Lot of ARP Broadcasts From One System / Machine”