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Full Discussion: Problem with eval a generated and interpreted variable name and its value
Top Forums Shell Programming and Scripting Problem with eval a generated and interpreted variable name and its value Post 302897899 by Corona688 on Wednesday 16th of April 2014 05:47:54 PM
Old 04-16-2014
eval is almost never the answer. The same usually goes for dynamic variable names. If you find yourself using either, you've taken a wrong turn somewhere.

You can use a here-document to safely turn your variables into strings. Much better than eval.

Code:
echo "cat <<EOF" >> /tmp/$$
# copy into /tmp/$$ removing backticks and () to prevent accidental/malicious execution of commands
tr -d '`()' < configfile >> $/tmp/$$
echo "EOF" >> /tmp/$$

. /tmp/$$ > /tmp/$$-1

rm /tmp/$$

It works by creating a file like this:

Code:
cat <<EOF
bookmark
bookmark
bookmark
EOF

...and running it in your shell to create another file.

/tmp/$$-1 should now contain the same text as your GTK file with $VARIABLE names substituted.

TIP: You can do ${VARNAME}stuff instead of $VARNAME stuff in your config file. The shell will look for the { } so you won't need spaces to separate them out.
Last edited by Corona688; 04-16-2014 at 07:04 PM..
This User Gave Thanks to Corona688 For This Post:
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LEARN ABOUT OPENSOLARIS

xdg-user-dir

xdg-user-dir(1) 						   User Commands						   xdg-user-dir(1)

NAME

       xdg-user-dir - Get the path used for desktop user directory location.

SYNOPSIS

       xdg-user-dir DIR

DESCRIPTION

       xdg-user-dir is a utility that extracts the location of the specified desktop user directory from the file :

	   ${HOME}/.config/user-dirs.dirs

OPERANDS

       Valid desktop directories (DIR) are:

	       DESKTOP
	       DOWNLOAD
	       TEMPLATES
	       PUBLICSHARE
	       DOCUMENTS
	       MUSIC
	       PICTURES
	       VIDEOS

       If an invalid directory is requested ${HOME} is returned.

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of the following environment variables:

	   HOME.

       Other environment variable that are used are:

       XDG_CONFIG_HOME

	   Base directory for storge of XDG configuration files. Defaults to ${HOME}/.config

FILES

       The following files are used by this application:

       /usr/bin/xdg-user-dir

	   XDG Directory expansion utility.

       ${XDG_CONFIG_HOME}/user-dirs.dirs

	   Location of the user-specific configuration including the current list of directories and what they map to.

EXAMPLES

       Example 1: Location of user's documents directory

       % xdg-user-dir DOCUMENTS

       /home/user/Documents

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWxdg-user-dirs 	   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Uncommitted		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       More information can be found at:

       http://www.freedesktop.org/wiki/Software/xdg-user-dirs

       xdg-user-dirs-update(1), xdg-user-dirs-gtk-update(1), attributes(5)

NOTES

       Written by Darren Kenny, Sun Microsystems Inc, 2008

SunOS 5.11							    03 Apr 2008 						   xdg-user-dir(1)
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