TweetFollow Us on Twitter

Mac In The Shell: More from the Unknown

Volume Number: 23 (2007)
Issue Number: 07
Column Tag: Mac In The Shell

More from the Unknown

More shell tools that typically go unnoticed

by Edward Marczak

Introduction

OS X has an incredible breadth and depth available in the tools accessible from a shell. So much so, that it's hard to know each and every tool available. Some are almost hidden: tucked away in places one does not typically look. Others are hidden in plain sight: exactly where you'd expect them, but buried among the volume. This month, I'm going to dig out and introduce some more useful shell tools that you may not know about.

text manipulation

It's long been the domain of scripting languages like perl, and perhaps now to a lesser extent PHP, to slice, dice and otherwise manipulate text. However, there's a framework built right into OS X, so why not take advantage of it? The Cocoa text system is exposed to the shell via the "textutil" application. "textutil" can convert and manipulate many different formats of text documents. In fact, it works with a surprising number formats:

   txt
   html
   Microsoft Word "doc"
   Microsoft Word XML
   rtf
   webarchive

It's also incredibly easy to get started. Using the "-convert" switch, you can accomplish most conversions that you'd ever want:

textutil -convert html resume.doc

This will convert the Microsoft Word-based "resume.doc" into a separate HTML document named "resume.html". I'll immediately point out that textutil writes much, much better HTML than Word.

Note that the input format is determined 'automagically' by a number of methods. If textutil misidentifies the format of the source file, you tell it with the "-format" switch:

textutil -format html -convert rtf file1

This will tell textutil that "file1" is an HTML file, and we want to convert it into a rich text format file named "file1.rtf".

There's also a very handy "-info" switch that returns info on a given file:

$ textutil -info 2007-01-On\ Logs.doc
File:  2007-01-Marczak On Logs.doc
Type:  Word format
Size:  25600 bytes
Length:  3746 characters
Title:  MacTech Template
Author:  Classics Department
Last Editor:  Edward Marczak
Company:  Radiotope
Subject:  
Keywords:  
Created:  2006-11-02 17:56:00 -0500
Last Modified:  2006-11-06 09:47:00 -0500

As you can see, documents sometimes have incorrect metadata. Well, textutil can help you handle that as well! There are a number of metadata related switches:

strip: Remove metadata in target during conversion.

title: Set the title metadata attribute for output files.

author: Set the author metadata attribute for output files.

subject: Specify the subject metadata attribute for output files.

keywords: a shell-quoted list of 'tags' ("keyword1,keyword2, ...")

comment: Set the comment attribute for the output files.

editor: val Set the editor attribute for output files.

company: val Set the company attribute for output files.

creationtime: Set the creation time attribute for output files (in "yyyy-mm-ddThh:mm:ssZ" format).

modificationtime: Set the modification time attribute for output files (in "yyyy-mm-ddThh:mm:ssZ" format).

So, we could create an HTML document from a plain text file with the title and keywords set by running textutil like this:

textutil -convert html -title "Anti-gravity Thesis" -keywords "(anti,gravity,'atom power',physics)" -author "Bruce Banner" ag-file.txt

You'll find a well-formed HTML file with a little bit of CSS. Of course, there are many times when you need finer control over the tags that will be used in that HTML. Have no fear! The "-excludedelements" switch can help you out. This switch allows you to specify which HTML elements should not be used in the generated HTML. Like the "-keywords" switch, "-excludedelements" expects a single argument, so you can use a shell-quoted list of tags to skip.

Keep it clean

Speaking of well-formed HTML, manipulating tags and their parameters is a special case of text manipulation. Fortunately, tidy, the standard Unix utility just for this purpose, ships with OS X. So, if you've used textutil to generate HTML based output, tidy can take you even further.

The simplest case lets tidy modify your HTML document in place. To do so, use the "-m" switch:

$ tidy -im ag-file.html
Info: Doctype given is "-//W3C//DTD HTML 4.01//EN"
Info: Document content looks like HTML 4.01 Strict
No warnings or errors were found.

Take look at your file before and after running the tidy command. I also like to include the "-i" switch, which ensures tag levels are indented appropriately. Also, by default, tidy will lowercase all tags (which, by me, is "correct"). This can be overridden with the "-u" switch.

One of my absolute favorite uses of tidy is to get rid of "illegal" characters. This is easily accomplished with the "-b" (bare) switch. This strips the document of smart quotes, and dashes, and other characters that cause problems in HTML documents.

There's much, much more that tidy can do. Check the very well written man page to look at more options. Don't forget, though, that you can combine textutil and tidy into one neat shell statement:

textutil -stdout ag-file.txt -convert html | tidy -i -output ag-file.html

This command uses textutil to convert a text file to HTML, and sends the output to stdout. Then, that output is piped to tidy, which then requires us to use the "-output" switch to write the file to disk.

Finally, realize that both textutil and tidy can be used with a wildcard character to process an entire group of files. If all files are in a single directory, simply change to that directory and:

textutil -convert html *.doc

This will convert all Word documents in the current directory into HTML files. To process the current folder and all subfolders, use the find utility:

find . -name \*txt -print0 | xargs -0 textutil -convert html

I opted for xargs over find's exec command to ensure that large directories can be processed. You can scrub Word metadata in-place using this technique:

textutil -strip -convert doc *.doc

Painless, right?

Image Manipulation

While slinging text around may be a common, and very specific operation, doing the same to images requires a different set of tools. OS X's scriptable image processor server or, "sips" is just the ticket.

Like textutil, sips leans on frameworks already built into the core of OS X. This, of course, lets you do all of the great things that you can with a GUI right in a shell! Why is this exciting? Automation, naturally.

In the past, I've put together both nightly reports and 'one-click-builds' of documents using both user submitted and random images. The trick is not so much the content, but the dimensions of the graphic: you need consistent dimensions so you can automate your layout. Resizing graphic files is one of the things that sips does best:

sips -Z 100x100 IMG_1312.JPG --out image1-sized.jpg

The "-Z" switch is really nice: it keeps the proportions of the original image, but makes sure neither the width or height exceed the dimensions specified. The "--out" switch writes the result to a new file. The image you just made doesn't have a nice preview icon in the Finder? Add one:

sips -i image1-sized.jpg

Oh, you didn't want a JPEG format file? Convert it at the same time using the "-s" (setProperty) switch (let's do it all in one shot):

sips -Z 100x100 IMG_1312.JPG -i -s format png --out image-sized.png

This one command resizes the graphic, converts the output to png and creates the Finder preview icon. Nice.

For automation, though, you often need to find out information about the source before you blindly process it. Again, like textutil, sips has functions for this. You can dump all of an image's data with the "-g all" switch and parse the output yourself:

$ sips -g all IMG_1312.JPG 
/Users/erm/Pictures/Parade/IMG_1312.JPG
  pixelWidth: 2592
  pixelHeight: 1944
  typeIdentifier: public.jpeg
  format: jpeg
  formatOptions: default
  dpiWidth: 180.000
  dpiHeight: 180.000
  samplesPerPixel: 3
  bitsPerSample: 8
  hasAlpha: no
  space: RGB
  profile: Camera RGB Profile
  creation: 2007:04:04 17:23:31
  make: Canon
  model: Canon PowerShot S2 IS

...or, you can request one or more of these parameters directly:

$ sips -g pixelWidth -g pixelHeight IMG_1312.JPG
/Users/marczak/Pictures/Parade/IMG_1312.JPG
  pixelWidth: 2592
  pixelHeight: 1944

Like textutil, feel free to throw a wildcard at sips, or, use the find/xargs trick.

Why?

So, why go through this trouble, when you can fire up Photoshop and make your changes (and even script it!), or use a Word processor to mold your words? Again, automation comes to mind. Specifically, automation with low overhead. Using the shell tools, you can run scripts on a server without having a GUI or installing an application like Photoshop at all. Combine this with some of the techniques I presented in April, and you can achieve some incredibly complex workflows.

Even cooler: more and more GUI utilities have some way to run shell jobs. Textmate, for example, can run a selection or entire document through a shell tool and plop the results right back in the live document. Even apps that don't have this functionality built in can usually be faked thanks to AppleScript. Take Mail.app, for instance. It lets you create signatures, but not dynamic signatures that rely on a running process. What if you wanted to include a snapshot from your iSight in your sig? Script a capture from isightcapture (http://www.intergalactic.de/hacks.html), run it through sips and AppleScript the copy and pasting of into Mail.

Or, consider a simpler alternative: you've installed fortune and want a random fortune in your sig. A simple bash script could be as follows:

#!/bin/bash
# Tell Mail.app to select all and copy to clipboard
osascript <<MailCopy
tell application "System Events"
        tell application "Mail" to activate
        keystroke "a" using {command down}
        keystroke "c" using {command down}
end tell
MailCopy
# Write clipboard to file
pbpaste > /tmp/mailpaste.tmp
fortune -s >> /tmp/mailpaste.tmp
textutil -stdout -convert rtf /tmp/mailpaste.tmp | pbcopy
# Tell Mail.app to activate and paste in the contents of the clipboard
osascript <<MailPaste
tell application "System Events"
        tell application "Mail" to activate
        keystroke "a" using {command down}
        keystroke "v" using {command down}
end tell
MailPaste

This is admittedly a quick hack with absolutely no error checking or other niceties. However, if you open up Mail.app, create a new message, put your cursor anywhere in the body and run this, you'll get a fortune tagged onto the end of your message (it helps if you already have a sig created). Pretty it up a bit and you could run it via the GUI via a ".command" file, or, wrap it in AppleScript and run it from your script menulet. Or, if you're a Quicksilver user, don't ignore the qs shell tool.

Of course, the real power lies in integrating other data: from the web, from Excel, from a database....wherever!

Conclusion

When venerable shell tools are integrated with the power of OS X, the workflow possibilities truly are endless. Be creative in your application of scripting tools, and you'll be able to solve any problem for your client/employer/self.

Media of the month: Brendan Benson's new album, "Alternative to Love". It's just good, fun pop music, no strings attached.

Until next month, keep thinking of ways to keep the work flowing.

References:

"Developer Release Note": http://developer.apple.com/releasenotes/Cocoa/AppKit.html


Ed Marczak owns and operates Radiotope, a technology consultancy that just tries to make life easier through the technology that already exists. He's also the Executive Editor of MacTech Magazine, and CTO of WheresSpot. His copious free time is spent with his wife and two daughters, currently enjoying the weather in the North East U.S.

 
AAPL
$103.61
Apple Inc.
+1.11
MSFT
$44.94
Microsoft Corpora
-0.50
GOOG
$574.98
Google Inc.
+3.38

MacTech Search:
Community Search:

Software Updates via MacUpdate

NetShade 6.0.2 - Browse privately using...
NetShade is an Internet security tool that conceals your IP address on the web. NetShade routes your Web connection through either a public anonymous proxy server, or one of NetShade's own dedicated... Read more
Mac DVDRipper Pro 5.0 - Copy, backup, an...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
pwSafe 3.1 - Secure password management...
pwSafe provides simple and secure password management across devices and computers. pwSafe uses iCloud to keep your password databases backed-up and synced between Macs and iOS devices. It is... Read more
StatsBar 1.8 - Monitor system processes...
StatsBar gives you a comprehensive and detailed analysis of the following areas of your Mac: CPU usage Memory usage Disk usage Network and bandwidth usage Battery power and health (MacBooks only)... Read more
Path Finder 6.5.5 - Powerful, award-winn...
Path Finder is a file browser that combines the familiar Finder interface with the powerful utilities and innovative features. Just a small selection of the Path Finder 6 feature set: Dual pane... Read more
QuarkXPress 10.2.1 - Desktop publishing...
With QuarkXPress, you can communicate in all the ways you need to -- and always look professional -- in print and digital media, all in a single tool. Features include: Easy to Use -- QuarkXPress is... Read more
Skype 6.19.0.450 - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more
VueScan 9.4.41 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Cloud 3.0.0 - File sharing from your men...
Cloud is simple file sharing for the Mac. Drag a file from your Mac to the CloudApp icon in the menubar and we take care of the rest. A link to the file will automatically be copied to your clipboard... Read more
LibreOffice 4.3.1.2 - Free Open Source o...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more

Latest Forum Discussions

See All

Tiny Tower Vegas Review
Tiny Tower Vegas Review By Jennifer Allen on September 2nd, 2014 Our Rating: :: STEADY DEVELOPMENTUniversal App - Designed for iPhone and iPad Build a huge tower again but Vegas-style in Tiny Tower Vegas.   | Read more »
The Manhattan Project Review
The Manhattan Project Review By Andrew Fisher on September 2nd, 2014 Our Rating: :: ROCKET SCIENCEUniversal App - Designed for iPhone and iPad The Manhattan Project offers a great Euro-style gameplay experience, but it is totally... | Read more »
Rhonna Designs Magic (Photography)
Rhonna Designs Magic 1.0 Device: iOS Universal Category: Photography Price: $1.99, Version: 1.0 (iTunes) Description: Want to sprinkle *magic* on your photos? With RD Magic, you can add colors, filters, light leaks, bokeh, edges,... | Read more »
This Week at 148Apps: August 25-29, 2014
Shiny Happy App Reviews   | Read more »
Qube Kingdom – Tips, Tricks, Strategies,...
Qube Kingdom is a tower defense game from DeNA. You rally your troops – magicians, archers, knights, barbarians, and others – and fight against an evil menace looking to dominate your kingdom of tiny squares. Planning a war isn’t easy, so here are a... | Read more »
Qube Kingdom Review
Qube Kingdom Review By Nadia Oxford on August 29th, 2014 Our Rating: :: KIND OF A SQUARE KINGDOMUniversal App - Designed for iPhone and iPad Qube Kingdom has cute visuals, but it’s a pretty basic tower defense game at heart.   | Read more »
Fire in the Hole Review
Fire in the Hole Review By Rob Thomas on August 29th, 2014 Our Rating: :: WALK THE PLANKUniversal App - Designed for iPhone and iPad Seafoam’s Fire in the Hole looks like a bright, 8-bit throwback, but there’s not enough booty to... | Read more »
Alien Creeps TD is Now Available Worldwi...
Alien Creeps TD is Now Available Worldwide Posted by Ellis Spice on August 29th, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Dodo Master Review
Dodo Master Review By Jordan Minor on August 29th, 2014 Our Rating: :: NEST EGGiPad Only App - Designed for the iPad Dodo Master is tough but fair, and that’s what makes it a joy to play.   | Read more »
Motorsport Manager Review
Motorsport Manager Review By Lee Hamlet on August 29th, 2014 Our Rating: :: MARVELOUS MANAGEMENTUniversal App - Designed for iPhone and iPad Despite its depth and sense of tactical freedom, Motorsport Manager is one of the most... | Read more »

Price Scanner via MacPrices.net

Apple refurbished iPads available for up to $...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more
Are We Now In The Post-Post-PC Era?
A longtime and thoroughgoing laptop aficionado, I was more than a little dismayed by Steve Jobs’s declaration back in 2010 when he sprang the iPad on an unsuspecting world. that we’d entered a “post-... Read more
PC Outlook Improves, But 2014 Shipments Still...
According to the International Data Corporation (IDC) Worldwide Quarterly PC Tracker, worldwide PC shipments are expected to fall by -3.7 percent in 2014. To hat’s actually an improvement from the... Read more
IDC Lowers Tablet Sales Projections for 2014...
Following a second consecutive quarter of softer than expected demand, International Data Corporation (IDC) has lowered its worldwide tablet plus 2-in-1 forecast for 2014 to 233.1 million units. The... Read more
Apple now offering refurbished 21-inch 1.4GHz...
The Apple Store is now offering Apple Certified Refurbished 21″ 1.4GHz iMacs for $929 including free shipping plus Apple’s standard one-year warranty. Their price is $170 off the cost of new models,... Read more
Save $50 on the 2.5GHz Mac mini, on sale for...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $300 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... Read more
The Rise of Phablets
Carlisle & Gallagher Consulting Group, a businesses and technology consulting firm focused solely on the financial services industry, has released an infographic depicting the convergence of... Read more
Bad Driver Database App Allows Good Drivers t...
Bad Driver Database 1.4 by Facile Group is a new iOS and Android app that lets users instantly input and see how many times a careless, reckless or just plain stupid driver has been added to the... Read more
Eddy – Cloud Music Player for iPhone/iPad Fre...
Ukraine based CapableBits announces the release of Eddy, its tiny, but smart and powerful cloud music player for iPhone and iPad that allows users to stream or download music directly from cloud... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.