Monthly Archives: October 2007

UNIX Tip: Backspace Key Does Not Work?!?

Here’s a common problem that our users complains about: The Problem When they telnet or ssh or connect to a remote host, the backspace key doesn’t seem to work. When pressed, all it shows are caret characters but it does not erase. The Solution Here’s one way of solving it… Type in: stty erase Then … Continue reading

Monitoring User Logins In UNIX

Here are some of the commands and files that you may want to check out if you want to monitor your users’ login activity on a Unix box (BSD/Solaris) The concerned files (Solaris): /var/adm/utmp(x) /var/adm/wtmp(x) /var/adm/lastlog The Commands: users* who w ac* last *may not be available in Solaris? All sample outputs show on this … Continue reading

Less is More

In a Linux system (and in Solaris 5.8, 5.9, 10, Solaris in general apparently), there are two (identical? opposite?) commands that are very easy enough to remember. How is that? Well, first the command names speak for itself or do exactly what it is called. What are those commands? Well, they are: more and and … Continue reading

View Network Traffic From Solaris Command Line

A request from a colleague was to check if there are traffic coming from a specific host to the local host. Both are running Solaris Unix, one is an Ultra5 (pretty old) and a Sparc Ultra 250, still old. specific interface There are many commands used by many UNIX admins to monitor network traffic going … Continue reading

Server refused to allocate pty Warning: no access to tty (Bad file number)

(Also for Solaris PTY. Setting up number of PTYs) That error was experienced when trying to connect to a server through ssh. The server being accessed here is a Sunfire V20 running Solaris 2.6. First glance, looks like that the maximum number of allowed ssh connection has been reached. This is a knows issue for … Continue reading

Loop Kill Mutiple PID On Bourne Shell

Just want to document it here. A colleague request to kill multiple PID owned by different users. They don’t have any special privilege to kill process other than their own. Here’s a simple for…loop script that will look for and kill each PID it found. #!/bin/sh -x ps -ef | grep nobody | awk ‘{print … Continue reading

Are You Into Ubuntu?

Well if you are, you better check the most popular Ubuntu blog on the blogosphere! Here’s the Top 5 on the list: Ubuntu Geek Ubuntu Blog Mark Shuttleworth The Fridge All About Linux

Checking and Repairing File system with fsck

fsck is the command used in UNIX for checking filesystem for any inconsistencies, usually caused by abnormal shutdown. These abnormal shutdown may be caused by some hardware failure or power failure. fsck also has options to repair filesystem as well. Syntax: fsck  [ -F fstype]  [-V]    [-yY]    [-o options]  special -F fstype     type of file system … Continue reading