If you use Mac OS X or some other *nix variant that doesn't come with ssh-copy-id, this one-liner will allow you to add your public key to a remote machine so you can subsequently ssh to that machine without a password.

shows all RPMs with files in the current directory & its subdirectories.

deletes logs not modified in over [#] days - modify to compress or move, as needed

changes THIS to THAT in all files matching fileglob* without using secondary files

Alternatively, if your password can contain a richer character set, try using 'uuencode' rather than base64. dd if=/dev/urandom bs=16 count=1 2>/dev/null | uuencode - Sample of that: '0:.CF\-@"\`W315VG^4O\.@``' Show Sample Output

For some of my web servers I setup and configure, for scaling I use the httpd.conf settings for these. Sometimes I forget which servers are prefork and which are worker MPM, so I use this to remind myself. Show Sample Output

mount with: mount -t msdos -o loop ./floppy.img /tmp/mnt

...if you get a certificate back, the server is accepting weak SSL ciphers

Bork, bork, bork! To keep it short, the first terminal line doesn't show a prompt. Show Sample Output

You need the RANDR support enable, to enable it with an ATI card run: aticonfig --set-pcs-str="DDX,EnableRandr12,TRUE" To show your available output run: xrandr -q -d [yourdisplay]

Does an in situ search-replace but leaves a datestamped backup. A variation with more precision: sed -i.`date +%Y%m%d%H%M%S 's/pattern/replace' [filename]

This command repeatedly gets the specified process' stack using pstack (which is an insanely clever and tiny wrapper for gdb) and displays it fullscreen. Since it updates every second, you rapidly get an idea of where your program is stuck or spending time. The 'tac' is used to make the output grow down, which makes it less jumpy. If the output is too big for your screen, you can always leave the 'tac' off to see the inner calls. (Or, better yet--get a bigger screen.) Caveats: Won't work with stripped binaries and probably not well with threads, but you don't want to strip your binaries or use threads anyway. Show Sample Output

Very quick way to change a word in a file. I use it all the time to change variable names in my PHP scripts (sed -i 's/$oldvar/$newvar/g' index.php)

customizable context searches - if you know sed, this is a basis for more complex context control than grep --context offers Show Sample Output

Shows a tree view of parent to child processes in the output of ps (linux). Similar output can be achieved with pstree (also linux) or ptree (Solaris). Show Sample Output

Grabs all rar files in any current subdirectories and feeds it to unrar. Doesn't work well with things packaged like file.part01.rar. Works best with File.rar. You can recurse into other directories by adding more /*'s

Limits the number of rows per table to X

Sometimes apache will get stuck in an established state where you can't get a list of the connecting IP's from mod_status... not a good thing when you need to ban an abusive ip.