TweetFollow Us on Twitter

Mac in the Shell: Pashua: Helping the GUI Crowd

Volume Number: 23 (2007)
Issue Number: 12
Column Tag: Mac in the Shell

Mac in the Shell: Pashua: Helping the GUI Crowd

Give your shell scripts a GUI

by Edward Marczak

Introduction

In the August 2006 issue of MacTech, I wrote an Mac in the Shell: Pashua: Helping the GUI Crowd, "GUI-up Your Script." It talked about ways to add a GUI to your shell script using AppleScript Studio, part of XCode. As we saw in that article, now on-line at http://www.mactech.com/articles/mactech/
Vol.22/22.08/GUI-upyourScript/index.html
, there are pros and cons to the shell scripter using this method. Since a year is an eternity in technology-time, I'm back to talk about some notable alternatives. My current fave? Pashua. Read on to see how you can use Pashua to add a GUI to your shell script.

What's Happening

The reasons for creating a GUI for a shell script remain the same: you're a shell scripter, but the person running the script is a GUI-type. Perhaps it's just a nicer way to ask for input. In any case, it's a powerful combination.

Before I get into Pashua, I'd like to mention some alternatives. Platypus (http://www.sveinbjorn.org/platypus) is a wrapper that will take a shell script and construct the necessary bundle structure to make the script a 'regular' double-clickable OS X ".app". Useful, in some cases, to create 'droplets' and to allow end-users to run shell scripts at login time via their Login Items. (Though, we'd never do that as good admins, we'd use launchd, right?). CocoaDialog (http://cocoadialog.sourceforge.net/), true to its name, allows the shell scripter to create dialogs. Not quite full windows. Think "error dialog" or "progress dialog." However, many times, that's precisely what you need, so, CocoaDialog exists, says what it does, and does a good job doing what it says.

However, Pashua is a bit more. Pashua will let you construct full windows, using most common GUI widgets. The best thing about Pashua is the ease in which you can get data in and out of the windows you create. Let's get started!

Good Times

First, go download Pashua itself at http://www.bluem.net/downloads/pashua_en/. From there, drop the distribution someplace logical (to your situation). We're shell people, right? So, get into Terminal, if you're not there already, and change into the new Pashua folder. From there, we'll dig into the Pashua.app bundle. Really, all you need to know is that from the shell you'll need the Pashua binary, located at Pashua.app/Contents/MacOS/Pashua. You may want to get this into your current $PATH so you can simply type Pashua from now on, but I'll leave that up to you. Go on and run that if you like - you'll receive the dialog show in figure 1.


Figure 1 - Ah, we need a config file.

As evidenced by the error dialog, Pashua is driven entirely by a config file. The config file is nothing esoteric - it's simply a text description that describes the window layout. Let's start with the easiest definition. Fire up your favorite text editor, and enter this:

uname.type = textfield
uname.label = Enter the user ID
uname.default = User ID
uname.width = 340

Save it as win_test.pash. This tells Pashua that we want a new element named "uname" to be created. The "uname" element will be a text field. It will have a label above the text field that says, "Enter the user ID", and will have default text of "User ID". Finally, we create the width of the field to be 340 pixels.

Enough chit-chat - let's run it. If you did get Pashua into your path, simply type:

Pashua win_test.pash

(If you didn't get it into your path, specify the full path to the Pashua binary instead. Something like: /Applications/Pashua/Pashua.app/Contents/MacOS/Pashua).

...and we're greeted with this:


Figure 2 - Our "Hello World" example.

Now, press the return key, or click the "OK" button. Notice what happens in the shell:

$ Pashua win_test.pash 
uname=User ID

That's right! Pashua simply takes the values of all elements and hands them to you on standard out. For shell scripters, this is a relief! Standard in and standard out: that's how shell scripting works! If you've tried to interface with AppleScript, you'll know that passing values back and forth is a huge pain in the patoot. Pashua is a shell-scripters GUI tool more than a GUI tool that simply has 'support' for scripting languages. So, onward!

Let's go for some eye candy. I'm going to put the MacTech logo in the header, and name the Window. Insert this above the lines already in win_test.pash:

# Set the window title
*.title=MacTech Utility
# Display an image
img.type = image
img.path = /Users/Shared/images/mt_logo.gif
img.border = 0

...and again, we display our window (Pashua win_test.pash) and see the results in figure 3.


Figure 3 - Ooooooh, fancy

After clicking OK, note that our output hasn't changed, as we haven't added any elements that accept input. You probably picked up that the hash mark ("#") denotes a comment, and Pashua will ignore any line beginning with one. Additionally, the "*" "element" affects the entire window itself. In addition to the title, so it's not "Pashua", you can also change the following window elements:

transparency: Sets the window's transparency, decimal value from 0 (invisible) to 1 (opaque)

appearance: Only allowed value is metal, which will create a "brushed metal" window. Under Leopard, "metal" creates a single, large "unified" window.

autoclosetime: If autoclosetime is set to an integer number larger than 1, the dialog will automatically close after the specified number of seconds have passed. Note that if a window auto-closes, no values are passed back.

floating: Setting floating to 1 will result in the window floating above other windows. (Note: does not work on Mac OS X 10.2)

x: Sets the horizontal position where the window should be opened on the screen (0 is the left border of the screen)

y: Sets the vertical position where the window should be opened on the screen (0 is the upper border of the screen)

Frankly, "title" is about all I use, as I like the auto-positioning on the screen, and I never seem to have need of the other attributes, but you may.

If you want to let a user bail out of an action, add a cancel button to the window:

cb.type = cancelbutton
cb.label = Cancel
cb.tooltip = Closes this window without taking action

Run our test window with this in the config file, but note the output when you cancel:

$ Pashua win_test.pash 
cb=1

If the cancel button is invoked - either by clicking or pressing the escape key, all values are discarded, and only the cancel button variable is returned.

The Love Boat

How about getting data in and out of our Window? Let's look at a few practical examples, starting with getting data out. We've already seen that Pashua returns its data on standard out. For the sake of it, let's add one more element, a checkbox. Add these lines beneath the textfield definition:

alter_account.type = checkbox
alter_account.label = Alter Account?
alter_account.tooltip = Checking this box will alter the account

Save, and now check out our window. Enter some data, and click the "OK" button. Notice the output:

$ Pashua win_test.pash 
uname=User ID
alter_account=1
cb=0

While that may be great for viewing on standard out in the shell itself, it doesn't help us too much in a script. To handle this gracefully, we really need to be in a script, which is where we want to be anyway. Let's look at a small, semi-robust wrapper script:

#!/usr/bin/env bash
if [ -N $1 ]; then
        echo "You need to supply the Pashua config file";
        exit 1
fi
result=`/Users/marczak/Applications/Pashua/Pashua.app/Contents/MacOS/Pashua $1 | sed 's/ /;;;/g'`
# Parse result
for line in $result
do
        key=`echo $line | sed 's/^\([^=]*\)=.*$/\1/'`
        value=`echo $line | sed 's/^[^=]*=\(.*\)$/\1/' | sed 's/;;;/ /g'`
        varname=$key
        varvalue="$value"
        eval $varname='$varvalue'
done

Save this a pwrapper.sh, and call it like this, with our sample window:

./pwrapper win_test.pash

Enter some data and click "OK". What happened? Seemingly nothing. No apparent output from Pashua. What's actually happening is that our wrapper script is capturing the output and assigning it to variables within the script. Those variables are now available to us directly. Now, the value passed back from uname is available in "$uname". While this wrapper script solves many problems for us, it doesn't go the distance if we need to dynamically create windows. For that, we need to use a little string creation and concatenation.

Fantasy Island

Following this article is a "complete" script that gathers local user accounts for a fictitious migration/alteration (Listing 1). The idea here is to show off Pashua, and not come up with a user-altering utility. The new bit here is that we create a drop-down menu that we populate dynamically at runtime.

The final window appears in figure 4. Note that the only output is generated purposefully by our script:

$ ./pwrapper.sh 
Converting user marczak
Also altering account


Figure 4 - Window with drop-down menu, generated dynamically.

The Gong Show

While this but scratches the surface of all that you can do with Pashua, I hope it was a helpful introduction that kick-starts your thoughts (and typing fingers!). Read the documentation included with the download for other elements that can be put into a window. Also, in the Examples folder, you'll find an application bundle that shows how to create a double-clickable app - all using your shell script and Pashua. If you're not a bash scripter, remember, Pashua accepts a text file as input, and sends its output via standard out. That's very friendly to any scripting language - Perl, Python, Ruby and more. There's even an AppleScript example.

Media of the month: Project management is my focus this month, and there are a lot of good books out there. Think about everything we do, and how many we could classify as "projects." Peruse your local bookstore's shelf for a project management title that suits you. I'm currently finishing up "The Zen Approach to Project Management: Working From Your Center to Balance Expectations and Performance" by George Pitagorsky. The "Zen" part of this title isn't to be taken lightly, and isn't being used as a fashion piece as many others do. This book won't teach you project management techniques per se, but it will teach you, using Zen "centering" exercises how to see the big picture when managing a project. Highly recommended, but only after you have some project management knowledge.

Here comes Macworld! One month away. I'll be presenting two (maybe three) topics this year. I'm leading a hands-on lab on Wednesday that teaches how to get started using the shell. So many people don't even know where to start at all, but know there's power at that cursor starting back at them. I'll also be presenting OS X Server Collaboration Tools, also on Wednesday along with Ben Greisler. This will talk about all the new features in Leopard server like iCal server, the new Wiki and more. Finally, I may be sitting in with Schoun Regan to talk about Kerberos on Tuesday in the Power Tools session, which will be informative if I'm there or not. Of course, don't miss the MacTech booth, where I'll be popping up at from time to time. Hope to see everyone in San Francisco!


Ed Marczak owns and operates Radiotope, a technology consulting practice. Think technology is dy-no-myte? Find out more at http://www.radiotope.com

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Daylite 6.7.3 - Dynamic business organiz...
Daylite helps businesses organize themselves with tools such as shared calendars, contacts, tasks, projects, notes, and more. Enable easy collaboration with features such as task and project... Read more
VirtualBox 6.0.10 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
BetterTouchTool 3.149 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more
Dropbox 77.4.131 - Cloud backup and sync...
Dropbox is an application that creates a special Finder folder that automatically syncs online and between your computers. It allows you to both backup files and keeps them up-to-date between systems... Read more
MainStage 3 3.4.3 - Live performance too...
Apple MainStage makes it easy to bring to the stage all the same instruments and effects that you love in your recording. Everything from the Sound Library and Smart Controls you're familiar with... Read more
Paperless 3.0.6 - $69.95
Paperless is a digital documents manager. Remember when everyone talked about how we would soon be a paperless society? Now it seems like we use paper more than ever. Let's face it - we need and we... Read more
TextMate 2.0.rc.29 - Code/markup editor...
TextMate is a versatile plain text editor with a unique and innovative feature set which caused it to win an Apple Design Award for Best Mac OS X Developer Tool in August 2006 A rapidly growing... Read more
Notability 4.0.4 - Note-taking and annot...
Notability is a powerful note-taker to annotate documents, sketch ideas, record lectures, take notes and more. It combines, typing, handwriting, audio recording, and photos so you can create notes... Read more
CleanMyMac X 4.4.4 - Delete files that w...
CleanMyMac makes space for the things you love. Sporting a range of ingenious new features, CleanMyMac lets you safely and intelligently scan and clean your entire system, delete large, unused files... Read more
Geekbench 4.4.0 - Measure processor and...
Geekbench provides a comprehensive set of benchmarks engineered to quickly and accurately measure processor and memory performance. Designed to make benchmarks easy to run and easy to understand,... Read more

Latest Forum Discussions

See All

TEPPEN guide - Tips and tricks for new p...
TEPPEN is a wild game that nobody asked for, but I’m sure glad it exists. Who would’ve thought that a CCG featuring Capcom characters could be so cool and weird? In case you’re not completely sure what TEPPEN is, make sure to check out our review... | Read more »
Dr. Mario World guide - Other games that...
We now live in a post-Dr. Mario World world, and I gotta say, things don’t feel too different. Nintendo continues to squirt out bad games on phones, causing all but the most stalwart fans of mobile games to question why they even bother... | Read more »
Strategy RPG Brown Dust introduces its b...
Epic turn-based RPG Brown Dust is set to turn 500 days old next week, and to celebrate, Neowiz has just unveiled its biggest and most exciting update yet, offering a host of new rewards, increased gacha rates, and a brand new feature that will... | Read more »
Dr. Mario World is yet another disappoin...
As soon as I booted up Dr. Mario World, I knew I wasn’t going to have fun with it. Nintendo’s record on phones thus far has been pretty spotty, with things trending downward as of late. [Read more] | Read more »
Retro Space Shooter P.3 is now available...
Shoot-em-ups tend to be a dime a dozen on the App Store, but every so often you come across one gem that aims to shake up the genre in a unique way. Developer Devjgame’s P.3 is the latest game seeking to do so this, working as a love letter to the... | Read more »
Void Tyrant guide - Guildins guide
I’ve still been putting a lot of time into Void Tyrant since it officially released last week, and it’s surprising how much stuff there is to uncover in such a simple-looking game. Just toray, I finished spending my Guildins on all available... | Read more »
Tactical RPG Brown Dust celebrates the s...
Neowiz is set to celebrate the summer by launching a 2-month long festival in its smash-hit RPG Brown Dust. The event kicks off today, and it’s divided into 4 parts, each of which will last two weeks. Brown Dust is all about collecting, upgrading,... | Read more »
Flappy Royale is an incredibly clever ta...
I spent the better part of my weekend playing Flappy Royale. I didn’t necessarily want to. I just felt like I had to. It’s a hypnotic experience that’s way too easy to just keep playing. | Read more »
Void Tyrant guide - General tips and tri...
Void Tyrant is a card-based dungeon-crawler that doesn’t fit in the mold of other games in the genre. Between the Blackjack-style combat and strange gear system alone, you’re left to your own devices to figure out how best to use everything to your... | Read more »
Webzen’s latest RPG First Hero is offici...
You might be busy sending your hulking Dark Knight into the midst of battle in Webzen’s other recent release: the long-anticipated MU Origin 2. But for something a little different, the South Korean publisher has launched First Hero. Released today... | Read more »

Price Scanner via MacPrices.net

Amazon drops prices, now offers clearance 13″...
Amazon has new dropped prices on clearance 13″ 2.3GHz Dual-Core non-Touch Bar MacBook Pros by $200 off Apple’s original MSRP, with prices now available starting at $1099. Shipping is free. Be sure to... Read more
2018 15″ MacBook Pros now on sale for $500 of...
Amazon has dropped prices on select clearance 2018 15″ 6-Core MacBook Pros to $500 off Apple’s original MSRP. Prices now start at $1899 shipped: – 2018 15″ 2.2GHz Touch Bar MacBook Pro Silver: $1899.... Read more
Price drop! Clearance 12″ 1.2GHz Silver MacBo...
Amazon has dropped their price on the recently-discontinued 12″ 1.2GHz Silver MacBook to $849.99 shipped. That’s $450 off Apple’s original MSRP for this model, and it’s the cheapest price available... Read more
Apple’s 21″ 3.0GHz 4K iMac drops to only $936...
Abt Electronics has dropped their price on clearance, previous-generation 21″ 3.0GHz 4K iMacs to only $936 shipped. That’s $363 off Apple’s original MSRP, and it’s the cheapest price we’ve seen so... Read more
Amazon’s Prime Day savings on Apple 11″ iPad...
Amazon has new 2018 Apple 11″ iPad Pros in stock today and on sale for up to $250 off Apple’s MSRP as part of their Prime Day sale (but Prime membership is NOT required for these savings). These are... Read more
Prime Day Apple iPhone deal: $100 off all iPh...
Boost Mobile is offering Apple’s new 2018 iPhone Xr, iPhone Xs, and Xs Max for $100 off MSRP. Their discount reduces the cost of an Xs to $899 for the 64GB models and $999 for the 64GB Xs Max. Price... Read more
Clearance 13″ 2.3GHz Dual-Core MacBook Pros a...
Focus Camera has clearance 2017 13″ 2.3GHz/128GB non-Touch Bar Dual-Core MacBook Pros on sale for $169 off Apple’s original MSRP. Shipping is free. Focus charges sales tax for NY & NJ residents... Read more
Amazon Prime Day deal: 9.7″ Apple iPads for $...
Amazon is offering new 9.7″ WiFi iPads with Apple Pencil support for $80-$100 off MSRP as part of their Prime Day sale, starting at only $249. These are the same iPads found in Apple’s retail and... Read more
Amazon Prime Day deal: 10% (up to $20) off Ap...
Amazon is offering discounts on new 2019 Apple AirPods ranging up to $20 (10%) off MSRP as part of their Prime Day sales. Shipping is free: – AirPods with Charging Case: $144.99 $15 off MSRP –... Read more
Amazon Prime Day deal: $50-$80 off Apple Watc...
Amazon has Apple Watch Series 4 and Series 3 models on sale for $50-$80 off Apple’s MSRP as part of their Prime Day deals with prices starting at only $199. Choose Amazon as the seller rather than a... Read more

Jobs Board

*Apple* Systems Architect/Engineer, Vice Pre...
…its vision to be the world's most trusted financial group. **Summary:** Apple Systems Architect/Engineer with strong knowledge of products and services related to Read more
*Apple* Graders/Inspectors (Seasonal/Hourly/...
…requirements. #COVAentryleveljobs ## Minimum Qualifications Some knowledge of agricultural and/or the apple industry is helpful as well as the ability to comprehend, Read more
Best Buy *Apple* Computing Master - Best Bu...
**710003BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Location Number:** 000171-Winchester Road-Store **Job Description:** Read more
Best Buy *Apple* Computing Master - Best Bu...
**709786BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Location Number:** 000430-Orange Park-Store **Job Description:** **What does a Read more
Geek Squad *Apple* Master Consultation Agen...
**709918BR** **Job Title:** Geek Squad Apple Master Consultation Agent **Job Category:** Services/Installation/Repair **Location Number:** 000106-Palmdale-Store Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.