Configuration File

Parse Configuration File

The parsefile function in the libmgesysutils library processes a configuration file consisting of sections and parameters of key / value pairs.

Whitespace lines and empty lines are ignored.

Lines with a '#' as the first non-whitespace character are ignored as comment lines.

The first parameter line must be a section header.

Section headers are enclosed in [], [ must be the first non-whitespace character on the line and anything after the first ] is ignored.

All other lines are assumed to be parameter lines and after any initial whitespace characters they must have a parameter name, optional whitespace, a mandatory '=', optional whitespace and finishing with an optional word of characters and / or numbers.

If a parameter is repeated then the last occurrence prevails.

An array of struct confsection's is provided by the library user to specify valid parameters and whether they are mandatory. A mandatory Key / Value pair for an optional Section is only enforced if the Section does appear, (is defined), in the config file.

EXAMPLE
\# Section General.
[General]
\# pollint is the polling interval in seconds.
pollint=5 <== This is legal.
large pollint=5 <== This is legal.
pollint = <== This is legal.
pollint <== This is illegal.


Use a pointer to something like the following array. The struct
confsection can be declared in myapp.h.
struct confsection sections[] = {
    {"General", 0, 0, {
        {"pollint", 0, 0, ""}
        }
    },
    {"Full", 0, 0, {
        {"Server", 0, 0, ""},
        {"DayOfWeek", 1, 0, ""}
        }
    },
    {"Incremental", 0, 0, {
        {"Server", 0, 0, ""},
        {"DayOfWeek", 0, 0, ""}
        }
    },
    {"Output", 1, 0, {
        {"Verbose", 1, 0, ""},
        {"Bold", 0, 0, ""}
        }
    }
};
N.B. There appear to be more braces than should be required
and this is so, however, removing the extra braces results
in compiler warnings.