An alias defined in .profile does not work when you open a bash window from the desktop. Simply put, alias should be put in .bashrc ; PATH should be put in .profile . These are the facts: .profile is executed by the login shell, i.e., when you login. .bashrc is executed whenever a bash shell is opened - login or non-login. When you open a new bash window from the desktop, a non-login shell is created, it will execute .bashrc , not .profile . When you ssh to a remote system interactively, a login shell is created. When you ssh to a remote system and run a command directly, a non-login shell is created. PATH modifications should be put in .profile since it is usually...

Oracle sqlplus command line tools does not support command line editing out-of-the-box. But on Linux there's a handy utility that enables command line editing with any command line tool: rlwrap - readline wrapper. Install rlwrap: $ sudo apt-get install rlwrap Create a keywords file .sql.dict (optional, but convenient): false null true access add as asc begin by chec... It would be nice to add the tables names also. Create an alias for sqlplus (put it in .bashrc ): alias sqlplus='rlwrap -f $HOME/.sql.dict sqlplus'

These are the steps to install the Oracle sqlplus command line utility on Ubuntu Linux: Get Oracle instant client packages from Oracle (you'll need basic or basiclite + sqlplus). Install the RPM files with alien : $ sudo alien -i oracle-instantclient11.2-basic-11.... Install Oracle shared libraries: create file /etc/ld.so.conf.d/oracle.conf and add this line: /usr/lib/oracle/11.2/client/lib then run sudo ldconfig

The MIPS CPU is able to run both big-endian and little-endian. So a system built on MIPS can be either big-endian (mips) or little-endian (mipsel). The file command shows the architecture: $ file ls ls: ELF 32-bit LSB executable, MIPS, ... but readelf will tell the endianness: $ readelf -h ls ELF Header: Magic: 7f 45...

Use the read command to pause a shell script and give the user a chance to stop it: #!/bin/sh echo "Press CTRL-C to stop this scrip...

I don't know if there's a fool proof way to find out which Linux distro you are running on, but here are some ways you can try: cat /proc/version cat /etc/issue cat /etc/*release lsb_release -a Results on Ubuntu 11.10 oneiric: $ cat /proc/version Linux version 3.0.0-13-gene... Results on Red Hat Enterprise Server: $ cat /proc/version Linux version 2.6.18-128.1....

The usual command " sudo apt-get install swftools " did not work for Ubuntu 11.10 (oneiric), so I installed from source: Install dependencies: $ sudo apt-get install zlib1g-dev libgif-dev libfr... Get swftools source: $ wget http://swftools.org/swftools-0.9.1.tar.gz ... Build and install: $ ./configure $ make $ sudo make install

Use tcpdump to monitor traffic on a network: To print all incoming and outgoing packets on host 192.168.0.1 : tcpdump host 192.168.0.1 To print all incoming and outgoing IP packets on host firebird : tcpdump ip host firebird To write raw packets to a file, rather than parsing and printing them out: tcpdump ip host firebird -w /tmp/firebird.pcap To listen on interface eth0 (without this, tcpdump listens on the lowest numbered, configured up interface except loopback): tcpdump -i eth0 ip Use switch -X for more verbose output: tcpdump -i eth0 ip -X host 192.168.0.1 Outgoing from 192.168.0.1 : tcpdump -i eth0 ip -X src host 192.168.0.1 Incoming to 192.168.0.1 : tcpdump -i eth0 ip -X dst host 192.168.0.1 More verbose output: tcpdump -i eth0 tcp -vvX host 192.168.0.1...

More like assign a second ip address to the same nic, instead of a virtual nic. Multiple IP addresses can be assigned to the same NIC, but all IP addresses must be on the same subnet - otherwise some IP addresses will not be accessible. From command line, assign IP address 192.168.0.2 to alias eth0:0 : sudo ifconfig eth0:0 192.168.0.2 netmask 255.255.2... But IP addresses added this way are not persistent. They are lost whent he OS is restarted. To make the additions persistent: For Fedora: $ su - # cd /etc/sysconfig/network-scripts/ ... The contents of ifcfg-eth0:0 should look like this: DEVICE=eth0:0 IPADDR=192.168.0.2 NETMASK=255... Restart network: # service network restart For Ubuntu: $ sudo vi /etc/network/interfaces Append this to the file: auto eth0:0 iface eth0:0 inet static name Et......

NAME brctl - ethernet bridge administration SYNOPSIS brctl [command] DESCRIPTION brctl is used to set up, maintain, and inspect the ethernet bridge configuration in the linux kernel. An ethernet bridge is a device commonly used to connect different networks of ethernets together, so that these ethernets will appear as one ethernet to the participants. Each of the ethernets being connected corresponds to one physical interface in the bridge. These individual ethernets are bundled into one bigger ('logical') ethernet, this bigger ethernet corresponds to the bridge network interface.