expand docu on configuration

doc/configuration-format.texi

@@ -0,0 +1,73 @@
+@c This file is used both in the exchange and merchant
+@c manuals. Edits should be propagated to both Gits!
+
+@node Configuration format
+@section Configuration format
+@cindex configuration
+
+In Taler realm, any component obeys to the same pattern to get configuration
+values.  According to this pattern, once the component has been installed, the
+installation deploys default values in @cite{$@{prefix@}/share/taler/config.d/}, in
+@cite{.conf} files.  In order to override these defaults, the user can write a custom
+@cite{.conf} file and either pass it to the component at execution time, or name it
+@cite{taler.conf} and place it under @cite{$HOME/.config/}.
+
+
+A config file is a text file containing @cite{sections}, and each section contains
+its @cite{values}. The right format follows:
+
+@example
+[section1]
+value1 = string
+value2 = 23
+
+[section2]
+value21 = string
+value22 = /path22
+@end example
+
+Throughout any configuration file, it is possible to use @code{$}-prefixed variables,
+like @code{$VAR}, especially when they represent filesystem paths.
+It is also possible to provide defaults values for those variables that are unset,
+by using the following syntax: @code{$@{VAR:-default@}}.
+However, there are two ways a user can set @code{$}-prefixable variables:
+
+by defining them under a @code{[paths]} section, see example below,
+
+@example
+[paths]
+TALER_DEPLOYMENT_SHARED = $@{HOME@}/shared-data
+..
+[section-x]
+path-x = $@{TALER_DEPLOYMENT_SHARED@}/x
+@end example
+
+or by setting them in the environment:
+
+@example
+$ export VAR=/x
+@end example
+
+The configuration loader will give precedence to variables set under @code{[path]},
+though.
+
+The utility @code{taler-config}, which gets installed along with the exchange, serves
+to get and set configuration values without directly editing the @cite{.conf}.
+The option @code{-f} is particularly useful to resolve pathnames, when they use
+several levels of @code{$}-expanded variables. See @code{taler-config --help}.
+
+Note that, in this stage of development, the file @code{$HOME/.config/taler.conf}
+can contain sections for @emph{all} the component. For example, both an exchange and
+a bank can read values from it.
+
+The repository @code{git://taler.net/deployment} contains examples of configuration
+file used in our demos. See under @code{deployment/config}.
+
+@cartouche
+@quotation Note
+Expectably, some components will not work just by using default values, as their
+work is often interdependent. For example, a merchant needs to know an exchange
+URL, or a database name.
+@end quotation
+@end cartouche
+

doc/taler-config.texi

@@ -0,0 +1,47 @@
+@c This file is used both in the exchange and merchant
+@c manuals. Edits should be propagated to both Gits!
+
+@node Using taler-config
+@section Using taler-config
+@cindex taler-config
+
+The tool @code{taler-config} can be used to
+extract or manipulate configuration values; however, the configuration
+use the well-known INI file format and can also be edited by hand.
+
+Run
+@example
+$ taler-config -s $SECTION
+@end example
+to list all of the configuration values in section @code{$SECTION}.
+
+Run
+@example
+$ taler-config -s $section -o $option
+@end example
+to extract the respective configuration value for option @code{$option}
+in section @code{$section}.
+
+Finally, to change a setting, run
+@example
+$ taler-config -s $section -o $option -V $value
+@end example
+to set the respective configuration value to @code{$value}. Note that you have to
+manually restart the Taler backend after you change the configuration to
+make the new configuration go into effect.
+
+Some default options will use $-variables, such as @code{$DATADIR}
+within their value.  To expand the @code{$DATADIR} or other $-variables
+in the configuration, pass the @code{-f} option to
+@code{taler-config}.  For example, compare:
+@example
+$ taler-config -s ACCOUNT-bank \
+               -o WIRE_RESPONSE
+$ taler-config -f -s ACCOUNT-bank \
+               -o WIRE_RESPONSE
+@end example
+
+While the configuration file is typically located at
+@code{$HOME/.config/taler.conf}, an alternative location can be
+specified to @code{taler-merchant-httpd} and @code{taler-config} using
+the @code{-c} option.

doc/taler-exchange.texi

@@ -339,6 +339,8 @@ at least eventually will do so, for now it is a somewhat wild
 description of some of the options.
 
 @menu
+* Configuration format::
+* Using taler-config::
 * Keying::
 * Serving::
 * Currency::
@@ -349,6 +351,12 @@ description of some of the options.
 
 @end menu
 
+@include configuration-format.texi
+@include taler-config.texi
+
+
+
+
 @node Keying
 @section Keying
 
@@ -775,7 +783,6 @@ that might be helpful to understand how the exchange operates, which files
 should be backed up.  The information may also be helpful for diagnostics.
 
 @menu
-* Configuration format::
 * Reserve management::
 * Database Scheme::
 * Signing key storage::
@@ -783,77 +790,6 @@ should be backed up.  The information may also be helpful for diagnostics.
 * Auditor signature storage::
 @end menu
 
-@node Configuration format
-@section Configuration format
-
-
-In Taler realm, any component obeys to the same pattern to get configuration
-values.  According to this pattern, once the component has been installed, the
-installation deploys default values in @cite{$@{prefix@}/share/taler/config.d/}, in
-@cite{.conf} files.  In order to override these defaults, the user can write a custom
-@cite{.conf} file and either pass it to the component at execution time, or name it
-@cite{taler.conf} and place it under @cite{$HOME/.config/}.
-
-
-A config file is a text file containing @cite{sections}, and each section contains
-its @cite{values}. The right format follows:
-
-@example
-[section1]
-value1 = string
-value2 = 23
-
-[section2]
-value21 = string
-value22 = /path22
-@end example
-
-Throughout any configuration file, it is possible to use @code{$}-prefixed variables,
-like @code{$VAR}, especially when they represent filesystem paths.
-It is also possible to provide defaults values for those variables that are unset,
-by using the following syntax: @code{$@{VAR:-default@}}.
-However, there are two ways a user can set @code{$}-prefixable variables:
-
-by defining them under a @code{[paths]} section, see example below,
-
-@example
-[paths]
-TALER_DEPLOYMENT_SHARED = $@{HOME@}/shared-data
-..
-[section-x]
-path-x = $@{TALER_DEPLOYMENT_SHARED@}/x
-@end example
-
-or by setting them in the environment:
-
-@example
-$ export VAR=/x
-@end example
-
-The configuration loader will give precedence to variables set under @code{[path]},
-though.
-
-The utility @code{taler-config}, which gets installed along with the exchange, serves
-to get and set configuration values without directly editing the @cite{.conf}.
-The option @code{-f} is particularly useful to resolve pathnames, when they use
-several levels of @code{$}-expanded variables. See @code{taler-config --help}.
-
-Note that, in this stage of development, the file @code{$HOME/.config/taler.conf}
-can contain sections for @emph{all} the component. For example, both an exchange and
-a bank can read values from it.
-
-The repository @code{git://taler.net/deployment} contains examples of configuration
-file used in our demos. See under @code{deployment/config}.
-
-@cartouche
-@quotation Note
-Expectably, some components will not work just by using default values, as their
-work is often interdependent. For example, a merchant needs to know an exchange
-URL, or a database name.
-@end quotation
-@end cartouche
-
-
 
 @node Reserve management
 @section Reserve management