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Full Discussion: How to export a variable from a subshell to the parent shell?
Top Forums Shell Programming and Scripting How to export a variable from a subshell to the parent shell? Post 302613043 by vomv1988 on Tuesday 27th of March 2012 12:57:51 PM
Old 03-27-2012
Quote:
Originally Posted by Scrutinizer
It does not malfunction, the subprocess opens and closes stdout and therefore the varying results. I used a sleep statement so that the reading process would be reading before the subprocess started opening the pipe...
Ahhh... so the trick is in the timing then... Nice one.

---------- Post updated 03-27-12 at 12:57 PM ---------- Previous update was 03-26-12 at 03:08 PM ----------

I recently found this unusual shell notation in a linux journal article:

Code:
command <(compound-list)

This creates a temporal fifo which is inputted whatever output the list of commands compound-list produces, and thus, command treats this output as if it belonged to a file. This way, <(compound-list) is treated as if it were a common filename. This must be an exclusive bash feature, since I don't recall reading of it in any of the shell programming books I've read, and when I tried looking it up in POSIX.1-2008 (not too thoroughly, I admit) I found it also says nothing about this feature. The feature appears in the Bash Reference Manual, under the section 3.5.6. Process Substitution.

Anyway, I thought it was worth mentioning it, since it's loosely related to this thread.
 

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LEARN ABOUT DEBIAN

photon

PHOTON(1)																 PHOTON(1)

NAME

       photon - generates photo albums

SYNOPSIS

       photon [OPTIONS] [PATH]

DESCRIPTION

       Photon generates clean, yet configurable, static HTML photo galleries. All of the work is done from the command line, and the resulting
       output can easily be configured by changing the template files found in /usr/share/photon/templates.

       To create a new template (skin), first create a new directory:

	  mkdir -p ${HOME}/.photon/templates/my_theme/

       Then copy the contents of /usr/share/photon/templates/photonv1/ to this new directory.  Photon only needs three files to build pages:

       index.html
	  used to display the content of a folder

       image.html
	  used to display the page for an image

       movie.html
	  used to display the page for a movie

       If a file is missing, then photon will throw an error and will not run.

HOW TO BUILD A GALLERY

       Quick start
	  $ photon -o myoutputdir /photos

       Use the gimp plugin
	  $ photon --resize-plugin=gimp -v -o myoutputdir /photos

       Change the size for all images and the thumbnail and keep the original photo
	  $ photon --sizelist=0,1600x1200,800x600 --thumbsize=320x240 -o myoutputdir /photos

       Create a gallery from your custom template (skin)
	  $ photon -k my_theme -o myoutputdir /photos

       See photon help
	  $ photon --help

OPTIONS

       -a | --awstats
	  Insert Javascript for Awstats

       --awstats-url=URL
	  Change default value for Awstats script url

       -c NAME | --comment
	  Name of the comment file (default .comments)

       -d NUM | --display-columns=NUM
	  Number of columns in index (default 3)

       -E | --no-exif
	  Don't include EXIF information in HTML file

       -f | --force
	  Overwrite non-image generated files (html, javascript, etc) (default no)

       -ff | --force --force
	  Overwrite image files (default no)

       -h | --help
	  Print this help

       -I | --no-index
	  Do not generate the high level index.html

       -J | --no-javascript
	  Do not use javascript (no shortcuts, ... )

       -k | --skin=THEME
	  Skin selector (default photonv1)

       --print-skins
	  Print out available skins (templates)

       -l NUM | --display-lines=NUM
	  Number of lines in index (default 5)

       -m | --movie
	  Movie mode, include link to movie (*.mov)

       -o NAME | --output-directory=NAME
	  Name of the output directory

       -s LIST | --sizelist=LIST
	  Image sizes (default 0,1024x768,800x600,640x480). Zero, which is the default, uses the original resolution. W x H specifies the width
	  and height of the image in pixels.

       -t SIZE | --thumbsize=SIZE
	  Size of thumbnails (default 160x120)

       -v | --verbose
	  Verbosely print information

       -V | --version
	  Print program version number

       -z | --compress
	  Compress the original image if selected (default copy the image)

       --exif-bordercolor=COLOR
	  Exif window border color (default #008000)

       --exif-bgcolor=COLOR
	  Exif window background color (default #f0fff0)

       --exif-fgcolor=COLOR
	  Exif window text color (default black)

       --body-bgcolor=COLOR
	  Body background color (default #ccccff)

       --img-bgcolor=COLOR
	  Image background color (default white)

       --exclude=PATTERN
	  Exclude files matching PATTERN

       --resize-plugin=PLUG
	  Where PLUG is the program used to create thumbnails internal: fastest method (default) gimp: use Gimp>1.x (better quality)

       --resize-quality-low=NUM
	  Quality for small image. 0 (bad) and 100 (good)

       --resize-quality-high=NUM
	  Quality for big image 0 (bad) and 100 (good)

       --gimp-program=PROG
	  use PROG for gimp

SHORTCUTS WHILE VIEWING AN IMAGE

	  n/SPACE     Go to the next image (with the same resolution)
	  p/BACKSPACE Go to the previous image (with the same resolution)
	  s	      Start/Stop the slideshow
	  +/-	      Increase/Decrease by one second the slideshow's period
	  h	      Show shortcut and help
	  i	      Show Exif information
	  z	      Change to the higher resolution [NOT YET IMPLEMENTED]

SEE ALSO

	  gimp(1)

AUTHOR

	  Written by Luc Saillard, <luc@saillard.org>

	  Main web site: http://www.saillard.org/programs_and_patches/photon/

	  This manual page was written by Kevin Coyner <kcoyner@debian.org> for the Debian project but may be used by others.

								    12/16/2006								 PHOTON(1)
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