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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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nsd-checkconf(8)						    nsd 3.2.12							  nsd-checkconf(8)

NAME
nsd-checkconf - NSD configuration file checker. SYNOPSIS
nsd-checkconf [-v] [-h] [-o option] [-z zonename] [-s keyname] configfile DESCRIPTION
nsd-checkconf reads a configuration file. It prints parse errors to standard error, and performs additional checks on the contents. The configfile format is described in nsd.conf(5). The utility of this program is to check a config file for errors before using it in nsd(8) or zonec(8). This program can also be used for shell scripts to access the nsd config file, using the -o and -z options. OPTIONS
-v After reading print the options to standard output in configfile format. Without this option, only success or parse errors are reported. -h Print usage help information and exit. -o option Return only this option from the config file. This option can to be used in conjunction with the -z option. The special value zones prints out a list of configured zones. This option is primarily used by nsdc to parse the config file from the shell. If the -z option is given, but the -o option is not given, nothing is printed. -s keyname Prints the key secret (base64 blob) configured for this key in the config file. Used to help shell scripts parse the config file. -z zonename Return the option specified with -o for zone 'zonename'. If this option is not given, the server section of the config file is used. This option is primarily used by nsdc to parse the con- fig file from the shell. The -o, -s and -z option print configfile options to standard output. FILES
/etc/nsd3/nsd.conf default NSD configuration file SEE ALSO
nsd(8), nsdc(8), nsd.conf(5), nsd-notify(8), nsd-patch(8), nsd-xfer(8), zonec(8) AUTHORS
NSD was written by NLnet Labs and RIPE NCC joint team. Please see CREDITS file in the distribution for further details. NLnet Labs jul 19, 2012 nsd-checkconf(8)
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