Posts Tagged ‘shell’

Searching GZipped Log Files

March 18th, 2014 1 comment

I have a few handy scripts for searching through log files, especially monitoring SSH login attempts. I cannot just grep through log files however, because the log files get “rolled”: compressed, and archived.

rob@kanga:/var/log $ ls -lh system.log*
-rw-r-----@ 1 root  admin   289K Mar 18 17:16 system.log
-rw-r-----  1 root  admin    79K Mar 18 00:00 system.log.0.gz
-rw-r-----  1 root  admin    39K Mar 17 00:02 system.log.1.gz
-rw-r-----  1 root  admin    36K Mar 16 00:02 system.log.2.gz
-rw-r-----  1 root  admin    35K Mar 15 00:02 system.log.3.gz
-rw-r-----  1 root  admin    25K Mar 14 00:01 system.log.4.gz
-rw-r-----  1 root  admin    69K Mar 13 00:01 system.log.5.gz
-rw-r-----  1 root  admin    68K Mar 12 00:01 system.log.6.gz
rob@kanga:/var/log $

Suppose you want to grep through your log files for SSH login activity, you can do it like this:

rob@kanga:/var/log $ { cat /private/var/log/system.log ; gunzip -c /private/var/log/system.*.gz ; } | grep sshd | wc -l
rob@kanga:/var/log $

The magic happens in the curly braces, which concatenates the standard output of all enclosed commands. Be sure to include a semicolon after the last command, right before the closing curly brace.

An even shorter example:

rob@kanga:/var/log $ { echo hello ; echo world ; } | cat -n
     1	hello
     2	world
rob@kanga:/var/log $
Categories: Utility Tags: , , , , , ,

Writing Finder Comments from the Command Line

August 7th, 2011 3 comments

I had some old (we’re talking Apple IIGS era old) files that I wanted to keep around, and I wanted Spotlight to show them if there was a valid hit. Many of the file formats I cannot read anymore, but even a raw dump of the file could at least reveal the information I needed. What I could not find online was a way to write Spotlight-findable data from the command line. My idea was to run the strings command and embed that as a comment. I finally figured it out on my own, and it involves embedding AppleScript in a shell script via osascript. Read more…

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Run Snow Leopard in Virtual Machine to retain PowerPC Applications

July 25th, 2011 31 comments

I finally discovered how to run Mac OS X 10.6 Snow Leopard in a virtual machine after I was caught off guard that Mac OS X 10.7 Lion no longer supports Rosetta, Apple’s technology for seamlessly running PowerPC applications on Intel processors. I have enough PowerPC applications (like The Print Shop, my old copy of PhotoShop, and my scanner driver) that I was not going to upgrade to Lion on my home computer, but since I have successfully installed Snow Leopard in a virtual machine, I think I will take the plunge after all (and thanks to this Front Row hack also). Read more…

Check for PowerPC Programs Before Upgrading to Lion

July 24th, 2011 6 comments

I discovered too late that Mac OS X 10.7 Lion does not support PowerPC executables as Snow Leopard did with Rosetta. I cannot say how long that would have kept me away from Lion, but I definitely would have done some more homework before taking the plunge. If you have not already upgraded, you might want to do a check to see what you might be losing: old printer drivers, scanners, obscure utilities. I have finally lost my scanner, which required a PPC driver in an old copy of Photoshop. Run one of these scripts to generate a list of all PPC-only executables on your system. Read more…

Categories: Utility Tags: , , ,

“Ultrafast” video compression with x264

July 19th, 2011 1 comment

The fastest video compression I have seen so far is using the x264 command line tool with its “ultrafast” preset. The resulting file has no audio, so it requires an extra step with QuickTime to finish the process. I recently review the compression software Elgato Turbo.264 HD Software Edition, and it was indeed faster than iTunes and QuickTime Player when converting to iPhone-compatible videos, but I noticed that x264 was faster still. Here are the steps you can take for “ultrafast” video compression.
Read more…

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Spotlight Searching at the Command Line

April 5th, 2011 3 comments

If you know about the mdfind command that lets you perform Mac OS X Spotlight searches at the command line (The Power of mdfind, O’Reilly), then you know it’s a good start but ultimately unsatisfactory. I made up a shell script mdfindi that helps me interactively navigate the results of mdfind when I SSH into my home computer. Of course I keep the script on my Dropbox as mentioned in an earlier post so that it is available to all of my computers.

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Bash Profile Sharing and Useful Scripts

March 17th, 2011 2 comments

If you live at the command line as I do, you probably have a number of aliases, functions, and status updates added to your ~/.bash_profile, ~/.bashrc, or similar file. With a little effort you can share the critical components across several computers either automatically (Dropbox or SugarSync) or manually. The key is to abstract away machine-specific references. The following are suggestions for useful additions to your command line lifestyle.

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Locate Your Mac Laptop If It Is Missing

January 19th, 2011 18 comments

There are commercial services to help you locate lost laptops, but I wanted a feature that required less software to be installed and fewer Big Brothers helping me out along the way. Using a few free tools and shell scripts, I cobbled together my own LoJack-type system that notifies me whenever my laptop awakes (I can’t help you if your computer is turned off).

Tools Used:

  • SleepWatcher: Executes commands of your choice when computer wakes, sleeps, etc
  • bash: Shell scripting
  • LocateMe: Free command line tool (from me) using Apple’s geolocating API
  • Notifo: Lightweight notification for iPhones, etc
  • Google Maps: Displaying your laptop location


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Titlecase at the Command Line (and Mac OS X Services)

September 24th, 2010 No comments

Sometimes I want to change a line of text to titlecase Where Every Word Is Uppercase, and I am rarely in a program that offers that feature natively. I am usually at the command line or in a web browser or some such thing. To that end I put together some command line scripts and an Automator Service so that I could have an appropriate filter.
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