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.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Logic Pro X 10.3 - Music creation and au...
Logic Pro X is the most advanced version of Logic ever. Sophisticated new tools for professional songwriting, editing, and mixing are built around a modern interface that's designed to get creative... Read more
iMazing 2.1.8 - Complete iOS device mana...
iMazing (was DiskAid) is the ultimate iOS device manager with capabilities far beyond what iTunes offers. With iMazing and your iOS device (iPhone, iPad, or iPod), you can: Copy music to and from... Read more
Civilization VI 1.0.2 - Next iteration o...
Sid Meier’s Civilization VI is the next entry in the popular Civilization franchise. Originally created by legendary game designer Sid Meier, Civilization is a strategy game in which you attempt to... Read more
TurboTax 2016 - Manage your 2016 U.S. ta...
TurboTax guides you through your tax return step by step, does all the calculations, and checks your return for errors and overlooked deductions. It lets you file your return electronically to get... Read more
Microsoft Office 2016 15.30 - Popular pr...
Microsoft Office 2016 - Unmistakably Office, designed for Mac. The new versions of Word, Excel, PowerPoint, Outlook and OneNote provide the best of both worlds for Mac users - the familiar Office... Read more
FotoMagico 5.3 - Powerful slideshow crea...
FotoMagico lets you create professional slideshows from your photos and music with just a few, simple mouse clicks. It sports a very clean and intuitive yet powerful user interface. High image... Read more
Acorn 5.6.1 - Bitmap image editor.
Acorn is a new image editor built with one goal in mind - simplicity. Fast, easy, and fluid, Acorn provides the options you'll need without any overhead. Acorn feels right, and won't drain your bank... Read more
Dash 3.4.3 - Instant search and offline...
Dash is an API documentation browser and code snippet manager. Dash helps you store snippets of code, as well as instantly search and browse documentation for almost any API you might use (for a full... Read more
Microsoft Remote Desktop 8.0.37 - Connec...
With Microsoft Remote Desktop, you can connect to a remote PC and your work resources from almost anywhere. Experience the power of Windows with RemoteFX in a Remote Desktop client designed to help... Read more
Macs Fan Control 1.4.7.0 - Monitor and c...
Macs Fan Control allows you to monitor and control almost any aspect of your computer's fans, with support for controlling fan speed, temperature sensors pane, menu-bar icon, and autostart with... Read more

Fire Emblem: Heroes coming to Google Pla...
Nintendo gave us our first look at Fire Emblem: Heroes, the upcoming mobile Fire Emblem game the company hinted at last year. Revealed at the Fire Emblem Direct event held today, the game will condense the series' tactical RPG combat into bite-... | Read more »
ReSlice (Music)
ReSlice 1.0 Device: iOS Universal Category: Music Price: $9.99, Version: 1.0 (iTunes) Description: Audio Slice Machine Slice your audio samples with ReSlice and create flexible musical atoms which can be triggered by MIDI notes or... | Read more »
Stickman Surfer rides in with the tide t...
Stickson is back and this time he's taken up yet another extreme sport - surfing. Stickman Surfer is out this Thursday on both iOS and Android, so if you've been following the other Stickman adventures, you might be interested in picking this one... | Read more »
Z-Exemplar (Games)
Z-Exemplar 1.4 Device: iOS Universal Category: Games Price: $3.99, Version: 1.4 (iTunes) Description: | Read more »
5 dastardly difficult roguelikes like th...
Edmund McMillen's popular roguelike creation The Binding of Isaac: Rebirth has finally crawled onto mobile devices. It's a grotesque dual-stick shooter that tosses you into an endless, procedurally generated basement as you, the pitiable Isaac,... | Read more »
Last week on PocketGamer
Welcome to a weekly feature looking back on the past seven days of coverage on our sister website, PocketGamer. It’s taken a while for 2017 to really get going, at least when it comes to the world of portable gaming. Thank goodness, then, for... | Read more »
ROME: Total War - Barbarian Invasion set...
To the delight of mobile strategy fans, Feral Interactive released ROME: Total War just a few months ago. Now the game's expansion, Barbarian Invasion is marching onto iPads as a standalone release. [Read more] | Read more »
Yuri (Games)
Yuri 1.0 Device: iOS iPhone Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: It's night. Yuri opens his eyes. He wakes up in a strange forest.The small, courageous explorer rides on his bed on casters in this... | Read more »
Space schmup Xenoraid launches on the Ap...
10Tons Xenoraid is out today on the App Store, bringing some high-speed space action to your mobile gadgets just in time for the weekend. The company's last premium title, another sci-fi game titled Neon Chrome, did quite well for itself, so... | Read more »
Star Wars: Force Arena Beginner's G...
Star Wars: Force Arena joined the populous ranks of Star Wars games on mobile today. It's a two-lane MOBA starring many familiar faces from George Lucas's famed sci-fi franchise. As with most games of this nature, Force Arena can be a little obtuse... | Read more »

Price Scanner via MacPrices.net

Laptop Market – Flight To Quality? – The ‘Boo...
Preliminary quarterly PC shipments data released by Gartner Inc. last week reveal an interesting disparity between sales performance of major name PC vendors as opposed to that of less well-known... Read more
IBM and Bell Transform Canadian Enterprise Mo...
IBM and Bell Canada have announced they are joining forces to offer IBM MobileFirst for iOS market-ready enterprise applications for iPad, iPhone or Apple Watch. Bell, Canada’s largest communications... Read more
Otter Products is Closing… For a Day of Givin...
On Thursday, Feb. 9, Otter Products is closing doors to open hearts. In partnership with the OtterCares Foundation, the company is pausing operations for a day so all employees can volunteer with... Read more
15-inch 2.2GHz Retina MacBook Pro on sale for...
Amazon has 2015 15″ 2.2GHz Retina MacBook Pros (MJLQ2LL/A) available for $1799.99 including free shipping. Apple charges $1999 for this model, so Amazon’s price is represents a $200 savings. Read more
Back in stock: Apple refurbished 13-inch Reti...
Apple has Certified Refurbished 2015 13″ Retina MacBook Pros available for up to $360 off original MSRP, starting at $1099. An Apple one-year warranty is included with each model, and shipping is... Read more
CalcTape for macOS 1.2 Adding Machine App for...
schoettler Software has announced CalcTape 1.2, an update to their desktop calculator for macOS. When it comes to adding long columns of numbers, doing complex calculations or playing around with... Read more
New MacBooks And MacBook Pros WIth Kaby Lake...
Digitimes’ Joseph Tsai cites a Chinese-language Economic Daily News (EDN) report that unnamed market watchers are predicting Apple MacBook shipments to grow 10 percent in 2017, and projecting 15... Read more
New 2016 13-inch MacBook Pros on sale for up...
B&H Photo has the new 2016 13″ MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.9GHz/512GB Touch Bar MacBook Pro... Read more
New 15-inch Touch Bar MacBook Pros in stock a...
B&H Photo has the new 2016 15″ Apple Touch Bar MacBook Pros in stock today and on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
Opera Announces Neon Concept Browser For Mac
Opera is inviting users to get a glimpse of what Opera for computers could become with its Opera Neon browser concept. Each Opera Neon feature is described as “an alternate reality” for the Opera... Read more

Jobs Board

*Apple* Retail - Multiple Positions (Multi-L...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* & PC Desktop Support Technician...
Apple & PC Desktop Support Technician job in Stamford, CT We have immediate job openings for several Desktop Support Technicians with one of our most well-known Read more
*Apple* macOS Systems Integration Administra...
…most exceptional support available in the industry. SCI is seeking an Junior Apple macOS systems integration administrator that will be responsible for providing Read more
*Apple* Premier Retailer - Service Technicia...
DescriptionSimply Mac is the largest premier retailer for Apple products and solutions. At Simply Mac we are all Apple , all the time. Same products. Same prices. Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.