Zentube

Another variation on the theme of zenity. I honestly like the way you can make simple front-ends. In addition, I'm doing something with youtube again, or more precisely, I'm doing stuff with youtube-dl.

So, the problem with youtube is that if you don't have Internet access, you obviously can't really use it, and there are certain instances where it'd come in handy. One such instance is when you're doing language teaching in an Internet-bereft classroom.

So there's youtube-dl to get some videos downloaded, but a person is not always in the mood for fiddling with the shell when preparing their lesson material.

Hence, this script provides the simples of interfaces to download videos via youtube-dl. That's pretty much it. Anyway, I think it's simple and does its job.

Oh, yeah, I played around with the idea of automatically installing a package if it is not available at the time of execution. It's a sort of experiment, to see if it can be done at all. I'm not sure how effective this is though. And it depends on apt and gksudo.

The code:

 
  1 #!/bin/bash 
  2 # 
  3 # Zentube 
  4 # 
  5 # A simple GUI front-end to youtube-dl. All you need to do is run it, 
  6 # and put in the address of the video, and the back-end tries to  
  7 # download the video. 
  8 # 
  9 # Parameters: 
 10 #   None 
 11 #  
 12 # Requires: 
 13 #   youtube-dl 
 14 #   zenity 
 15 #   gksudo & apt (if you want youtube-dl installed automatically) 
 16 # 
 17 # Author: 
 18 #   Konrad Siek <konrad.siek@gmail.com> 
 19 # 
 20 # License: 
 21 # 
 22 # Copyright 2008 Konrad Siek. 
 23 #  
 24 # This program is free software: you can redistribute it and/ 
 25 # or modify it under the terms of the GNU General Public  
 26 # License as published by the Free Software Foundation, either  
 27 # version 3 of the License, or (at your option) any later  
 28 # version. 
 29 #  
 30 # This program is distributed in the hope that it will be  
 31 # useful, but WITHOUT ANY WARRANTY; without even the implied  
 32 # warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR  
 33 # PURPOSE. See the GNU General Public License for more  
 34 # details. 
 35 #  
 36 # You should have received a copy of the GNU General Public  
 37 # License along with this program. If not, see  
 38 # <http://www.gnu.org/licenses/>.  
 39  
 40 # The downloader backend. 
 41 PACKAGE=youtube-dl
 42  
 43 # Output information. 
 44 OUTPUT_DIR=~/Videos/
 45 EXTENSION=.flv
 46 TEMP_FILE=/tmp/$(basename $0).XXXXXXXXXX
 47  
 48 # The quality of the output file can be adjusted here, or you can comment  
 49 # out this setting altogether, to get the default. 
 50 QUALITY=--best-quality
 51  
 52 # Exit code constants. 
 53 SUCCESS=0 
 54 INSTALLATION_ABORTED=1 
 55 INSTALLATION_FAILED=2 
 56 INVALID_VIDEO_ADDRESS=4 
 57 INVALID_OUTPUT_DIRECTORY=8 
 58 BACKEND_ERROR=16 
 59  
 60 # This is a convenience installer for apt-using distros, e.g. Ubuntu. 
 61 if [ -z "$(which $PACKAGE)" ] 
 62 then 
 63     # Ask whether to attempt automatic install of the missing package. 
 64     # If the answer is no, then quit with an error. 
 65     zenity --question \
 66         --title="Automatic installation" \
 67         --text="Can't find <b>$PACKAGE</b>. Should I try installing it?" \
 68     || exit $INSTALLATION_ABORTED 
 69  
 70     # Try installing the missing package, or quit with an error if the 
 71     # attempt is failed. 
 72     gksudo "apt-get install $PACKAGE" || exit $INSTALLATION_FAILED 
 73 fi 
 74  
 75 # Ask user for the URL of the video. 
 76 url=$(\ 
 77     zenity --entry \ 
 78     --title="Video address" \ 
 79     --text="What is the address of the video?" \ 
 80 ) 
 81 # If no URL is given, then quit. 
 82 [ -z "$url" ] && exit $INVALID_VIDEO_ADDRESS 
 83  
 84 # Move to the output directory, create it i necessary. 
 85 mkdir -p "$OUTPUT_DIR" || exit $INVALID_OUTPUT_DIRECTORY 
 86 cd "$OUTPUT_DIR" 
 87  
 88 # Make a temporary file to collect error messages from the downloader. 
 89 temp_file=$(mktemp $TEMP_FILE) 
 90  
 91 # Run the downloader. 
 92 $PACKAGE $QUALITY --title "$url" 2>"$temp_file" | \ 
 93     zenity --progress --pulsate --auto-kill --auto-close --text="Downloading..." 
 94  
 95 # Check for errors, and display a success of error dialog at the end. 
 96 errors=$(cat $temp_file) 
 97  
 98 if [ -z "$errors" ] 
 99 then 
100     # Display successful info. 
101     zenity --info --text="Download successful!" 
102  
103     # Remove temporary file. 
104     unlink "$temp_file" 
105  
106     # Exit successfully. 
107     exit $SUCCESS 
108 else 
109     # Display error dialog. 
110     zenity --error --text="$errors" 
111  
112     # Remove temporary file. 
113     unlink "$temp_file" 
114  
115     # Exit with an error code. 
116     exit $BACKEND_ERROR 
117 fi 

The code is also available at GitHub as bash/zentube.