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

Luminar 1.0.2 - Powerful, adaptive, conf...
Luminar is the new full-featured image editor that adapts to the way you edit photos. Over 300 essential tools to fix, edit, and enhance your photos with comfort. The future of photo editing is here... Read more
Slack 2.3.3 - Collaborative communicatio...
Slack is a collaborative communication app that simplifies real-time messaging, archiving, and search for modern working teams. Version 2.3.3: Fixed window zoom jumping back-and-forth OS X 10.9... Read more
WhatRoute 2.0.10 - Geographically trace...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the router... Read more
Luminar 1.0.2 - Powerful, adaptive, conf...
Luminar is the new full-featured image editor that adapts to the way you edit photos. Over 300 essential tools to fix, edit, and enhance your photos with comfort. The future of photo editing is here... Read more
WhatRoute 2.0.10 - Geographically trace...
WhatRoute is designed to find the names of all the routers an IP packet passes through on its way from your Mac to a destination host. It also measures the round-trip time from your Mac to the router... Read more
Slack 2.3.3 - Collaborative communicatio...
Slack is a collaborative communication app that simplifies real-time messaging, archiving, and search for modern working teams. Version 2.3.3: Fixed window zoom jumping back-and-forth OS X 10.9... Read more
Lens Blur 1.4.3 - True out-of-focus boke...
Lens Blur transforms your existing photo into true SLR-quality out-of-focus bokeh effect! Everyone needs a gorgeous personalized background for a social profile, blog, Web/UI design, presentation, or... Read more
CleanMyMac 3.6.0 - $39.95
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
DEVONthink Pro 2.9.8 - Knowledge base, i...
DEVONthink Pro is your essential assistant for today's world, where almost everything is digital. From shopping receipts to important research papers, your life often fills your hard drive in the... Read more
MacFamilyTree 8.1 - Create and explore y...
MacFamilyTree gives genealogy a facelift: modern, interactive, convenient and fast. Explore your family tree and your family history in a way generations of chroniclers before you would have loved.... Read more

Latest Forum Discussions

See All

Amateur Surgeon 4 Guide: Become the worl...
It's time to wield your trusty pizza cutter again, as Amateur Surgeon has returned with a whole fresh set of challenges (and some old, familiar ones, too). Starting anew isn't easy, especially when all you have at your disposal is a lighter, the... | Read more »
Le Parker: Sous Chef Extraordinaire (Ga...
Le Parker: Sous Chef Extraordinaire 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Telltale Games really is working on a Gu...
Telltale Games' next episodic adventure is indeed Guardians of the Galaxy. A document tied to the voice actors strike suggested that the project was in the work, but now we have direct confirmation following an announcement at the Game Awards that... | Read more »
Amateur Surgeon returns to iOS and Andro...
Amateur Surgeon and its two sequels disappeared from the App Store some time and it was sad days for all. But now, just in time for the holidays, the Adult Swim favorite makes its joyous return in the shape of Amateur Surgeon 4, a remake with... | Read more »
The best board games on mobile
Sometimes you need to ditch all of the high speed, high action games in favor of something a little more traditional. If you don't feel like parting ways from your mobile device, though, there are still plenty of ways to get that old-school fix.... | Read more »
The best Facebook Messenger Instant Game...
Facebook's new Instant Games is now here, meaning you can play games with your friends directly via Facebook. It's a fun new way to connect with friends, of course, but it's also proving to be a solid gaming experience in its own right, with a... | Read more »
You can now play game's on Facebook...
Facebook launched its new Instant Games platform in an exciting new attempt to engage its user base. As a result, you can now play a number of different games directly through Facebook Messenger. All of these games run with HTML5, meaning you play... | Read more »
Apollo Justice Ace Attorney (Games)
Apollo Justice Ace Attorney 1.00.00 Device: iOS Universal Category: Games Price: $.99, Version: 1.00.00 (iTunes) Description: Court Is Back In Session Star as rookie defense attorney, Apollo Justice, as he visits crime scenes,... | Read more »
KORG iWAVESTATION (Music)
KORG iWAVESTATION 1.0 Device: iOS Universal Category: Music Price: $19.99, Version: 1.0 (iTunes) Description: A revolutionary new world of sound.The Wave Sequence Synthesizer for iPad - KORG iWAVESTATION | Read more »
Don't Grind Guide: Tips for becomin...
Don’t Grind is a surprising, derpy little one touch game with fun hand-drawn graphics. The goal is simple -- get the high score without being chopped to bits. That can be tough when you’re not used to the game, and that’s compounded by the fact... | Read more »

Price Scanner via MacPrices.net

Parallels Toolbox 1.3 for Mac Offers 25 Singl...
Parallels has launched Parallels Toolbox 1.3 for Mac, an upgrade that adds five new utilities to the stand-alone application which was released in August and is available exclusively online at http... Read more
OWC Mercury Elite Pro Dual mini Ultra-Portabl...
OWC has introduced the new OWC Mercury Elite Pro Dual mini, a powerful yet ultra-portable dual-drive RAID solution. The new Mercury Elite Pro Dual mini packs phenomenal performance into a small... Read more
Clearance 13-inch Retina MacBook Pros availab...
B&H Photo has clearance 2015 13″ Retina Apple MacBook Pros available for up to $200 off original MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $... Read more
Roundup of 2016 13-inch 2.0GHz MacBook Pro sa...
B&H has the non-Touch Bar 13″ MacBook Pros in stock today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1449 $... Read more
New 13-inch 2.0GHz Space Gray MacBook Pro in...
Adorama has the new 13″ 2.0GHz Space Gray MacBook Pro (non-Touch Bar, MLL42LL/A) in stock for $1499 including a free 3-year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax... Read more
Finnair Adopts iOS Enterprise iPad Apps from...
Finnair and IBM have announced a first-of-its-kind agreement to utilize iOS enterprise apps from IBM to support the airline’s overall digital transformation. Finnair is focused on Asia-Europe traffic... Read more
Tech21 Launches Evo Go iPhone 7 Case Availabl...
Tech21 has announced the launch of the Evo Go case for Apple iPhone 7 and iPhone 7 Plus, exclusively at T-Mobile. Available online and at participating T-Mobile stores nationwide, Evo Go cases start... Read more
Apple Turns (RED) with More Ways to Join the...
In recognition of World AIDS Day, Apple is offering more ways than ever for customers to join (RED) in its mission to create an AIDS-free generation. Apple is the worlds largest corporate contributor... Read more
Deals on new 15-inch Touch Bar MacBook Pros,...
B&H Photo has new 2016 Apple 15″ Touch Bar MacBook Pro models in stock today with some available for $50 off MSRP, each including free shipping plus NY sales tax only: - 15″ 2.7GHz Touch Bar... Read more
12-inch Retina MacBooks on sale for up to $10...
12-inch Retina MacBooks remain on sale at B&H Photo with models available for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only. B&H will also include a free copy... Read more

Jobs Board

*Apple* Retail - Multiple Positions- White P...
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
Automotive Detailer - *Apple* Used Autos -...
We are currently conductinginterviews and will be accepting applications for a part-time detailer. Apple Used Autos is a great place to work andstart a career. We 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
US- *Apple* Store Leader Program - Apple (Un...
…Summary Learn and grow as you explore the art of leadership at the Apple Store. You'll master our retail business inside and out through training, hands-on Read more
*Apple* & PC Desktop Support Technician...
Apple & PC Desktop Support Technician job in Dallas TX Introduction: We have immediate job openings for several Desktop Support Technicians with one of our most Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.