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Full Discussion: Bash parameter expansion from a config file
Top Forums Shell Programming and Scripting Bash parameter expansion from a config file Post 302515572 by mrengert on Wednesday 20th of April 2011 12:14:09 PM
Old 04-20-2011
Bash parameter expansion from a config file
Hi -

I am trying to do a simple config file with known variable names in it, e.g.:

contents of config file a.conf:
-a
-b $work
-c $host
simplified contents of bash script file:
work='trunk'
host='alaska'
opts=$(tr '\n' ' ' < a.conf)
opts="$opts $*"
mycommand $opts arg1 arg2
The goal is to get the script to execute:
mycommand -a -b trunk -c alaska arg1 arg2
But no matter what I try, it always comes out:
mycommand -a -b $work -c $host arg1 arg2
I have tried various quoting methods and evals, but no go.

Can anyone suggest the proper syntax for this?

Note: this is a highly simplified example so I would rather not have to do some kind of sed/awk substitution on the config file contents.
 

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LEARN ABOUT DEBIAN

surfraw-update-path

SURFRAW-UPDATE-PATH(1)					User Contributed Perl Documentation				    SURFRAW-UPDATE-PATH(1)

NAME

       surfraw-update-path - updates PATH in shell config files

SYNOPSIS

       surfraw-update-path [-add] [-remove] [-check] [-sys] [-all] [-help] [-shell=SHELL]

DESCRIPTION

       surfraw-update-path adds the surfraw elvi directory (/usr/lib/surfraw) to your PATH in your shell's config file.

       Currently it supports bash, sh, csh, tcsh, ash, dash, ksh, pdksh, zsh, rc, and es

       Don't forget to login again or source your login files for it to take effect.

OPTIONS

       -check
	   Checks to see if the surfraw config code is present.  This is the default.

       -add
	   Adds the surfraw config code.

       -remove
	   Removes the surfraw config code

       -sys
	   Updates the system-wide shell config instead of the user.  Must be done as root.

       -shell=SHELL
	   Selects the shell to configure. Defaults to the value of the $SHELL environment variable.

	   Currently supported shells are:

	   sh, ash, bash, dash, csh, tcsh, ksh, pdksh, zsh, rc, and es.

       -all
	   Attempts to configure the startup files for all known shells

       -help
	   Gives a usage message

RETURN VALUE

       -check returns 0 if the surfraw code is present in the file, 1 if it is not found, or 2 on error.

       All other options return 0 on success, or 2 on error.

ENVIRONMENT

       SHELL
	   Used to determine which shell to configure, if -shell is not given.

       HOME
	   Used to find users config files.

       ENV Used by posix-compliant shells to specify a startup rc file.

       ZDOTDIR
	   Used to find user config files for zsh. If not set, defaults to HOME.

SEE ALSO

       surfraw(1), sh(1), ash(1), bash(1), dash(1), csh(1), tcsh(1), ksh(1), pdksh(1), zsh(1), rc(1), es(1)

AUTHOR

       Ian Beckwith <ianb@erislabs.net>

perl v5.12.4							    2011-07-12						    SURFRAW-UPDATE-PATH(1)
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