Tools a Unix administrator cannot live without

Question

After administering Unix or Unix-like servers, what tools (command-line preferably) do you feel you cannot live without?

Answer 1

screen is a must, especially with a good .screenrc file. I have it configured to display visually which window I'm in and can move between them with Ctrl+Arrow. For a single ssh session and multiple shells, it is a life saver.

Answer 2

• Bash
• Vim
• iostat
• ps
• top
• lsof
• strace
• tcpdump
• netstat
• find
• grep
• Perl
• sed
• tail
• dig
• traceroute

Where possible the GNU versions of the above over the propritary versions.

Answer 3

I love AWK as well as "for" on the command line.

Especially to build up a list of commands I want to run and then execute them all at once.

Answer 4

These are the tools I use on a daily basis (as a developer more than a system administrator)

• zsh
• lsof
• ps
• ack (or grep)
• find
• svn
• Python
• tar
• which
• fortune (a guy has to keep his sanity somehow)

Answer 5

All the standard commands and utilities (Bash, grep, sed, AWK, find, xargs, ssh, Vim, etc.)

• Lsof, awesome in so many ways, I love to use it for finding open ports AND the files associated with that process.
• Screen, for multi-session awesome.
• Tcpdump, its funny how many application problems are really weird network issues
• Ruby, makes more sense to me than Perl, becoming wildly popular for SA work.
• Chef, configuration management system.
• Capistrano, ssh in a for loop, but less crappy. And in Ruby.
• Rake, more sensible than make.

Answer 6

Perl and Vim. In that order. Anything else, I can use Perl to emulate somehow.

Answer 7

• rsync running over ssh to keep things consistent... in multiple directions (-gloptru[n]c)
• Vim and vimdiff to edit with 'folding' and viewing differences in scripts, logs, etc.
• Perl and (Ba)sh for scripting and analysis
• cURL (and maybe Wget) for posting/fetching data from ...
• Apache to webify them all (or at least create point-n-click admin tools)

Answer 8

shutdown

(this is just padding for my answer to be accepted)

Answer 9

• atop - yet another top alternative, great for monitoring changes in processes
• strace/ltrace - for tracking down those REALLY annoying bugs
• ldd - track down broken library dependencies
• cron, logrotate ;)

Of course, beyond command line, you need Nagios/Cacti/MRTG/etc...

Answer 10

Learn Vim or Emacs in and out!!
For text editing
Grep
Sed
AWK

For network tools
Nmap
dig

Answer 11

munin is a great tool for doing capacity analysis and review, but you need to set it up before you need it. We install it as a standard part of every server install we do.