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author | nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2006-09-22 23:03:08 +0000 |
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committer | nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2006-09-22 23:03:08 +0000 |
commit | 77c8c4e32c06a7d5f3a819db555cd637902a0856 (patch) | |
tree | d0fcd29ae8ff33e5f7876ff1e1a9af71d433fb7b | |
parent | 8d6d188205513b9472134f56f4da35b5f04e4c6f (diff) |
add basic documentation for the config file api
git-svn-id: svn://svn.openwrt.org/openwrt/branches/buildroot-ng/openwrt@4808 3c298f89-4303-0410-b956-a3cf2f4a3e73
-rw-r--r-- | docs/config.txt | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/docs/config.txt b/docs/config.txt new file mode 100644 index 000000000..59881580b --- /dev/null +++ b/docs/config.txt @@ -0,0 +1,72 @@ + == Structure of the configuration files == + +The config files are divided into sections and options/values. + +Every section has a type, but does not necessarily have a name. +Every option has a name and a value and is assigned to the section +it was written under. + +Syntax: + +config <type> [<name>] # Section + option <name> <value> # Option + + +Every parameter needs to be a single string and is formatted exactly +like a parameter for a shell function. The same rules for Quoting and +special characters also apply, as it is parsed by the shell. + + + + == Parsing configuration files in custom scripts == + +To be able to load configuration files, you need to include the common +functions with: + +. /etc/functions.sh + +Then you can use config_load <name> to load config files. The function +first checks for <name> as absolute filename and falls back to loading +it from /etc/config (which is the most common way of using it). + +If you want to use special callbacks for sections and/or options, you +need to define the following shell functions before running config_load +(after including /etc/functions.sh): + +config_cb() { + local type="$1" + local name="$2" + # commands to be run for every section +} + +option_cb() { + # commands to be run for every option +} + +You can also alter option_cb from config_cb based on the section type. +This allows you to process every single config section based on its type +individually. + +config_cb is run every time a new section starts (before options are being +processed). You can access the last section through the CONFIG_SECTION +variable. Also an extra call to config_cb (without a new section) is generated +after config_load is done. +That allows you to process sections both before and after all options were +processed. + +You can access already processed options with the config_get command +Syntax: + +config_get <section> <option> # prints the value of the option +config_get <variable> <section> <option> # stores the value inside the variable + +In busybox ash the three-option config_get is faster, because it does not +result in an extra fork, so it is the preferred way. + +Additionally you can also modify or add options to sections by using the +config_set command. + +Syntax: + +config_set <section> <option> <value> + |