Itai-Nelken / configuration_parser

A configuration parser that parses a subset of TOML.

configuration_parser

A configuration parser C library that parses a subset of TOML.

Installation

To install the library as a shared object, clone this repository and run the folowing from its root. Note that if your system uses a different folder for shared libraries (for example /lib), change the prefix to it (e.g for /lib, set the prefix to /).

mkdir build
cd build
cmake -DCMAKE_INSTALL_PREFIX=/usr ..
make
sudo make install

Note that root privileges are needed to install.
If you want to statically link the library with your project, the build produces a static library file as well.
To use it, simply compile it along with your code (e.g cc my_code.c libconfig_static.a -I/path/to/where/config_parser.h/is).
Note that if you use the static library, you will also need to copy the public header (/include/config_parser.h) to your project.

Example

See the example folder in this repository for a more complete example.

Usage

Assuming the following configuration file:

is_day = true

[Joe]
age = 42
favorite_food = "Vegetable soup"

The following code will read it:

#include <stdio.h>
#include <stdlib.h>
#include <config_parser.h>

int main(void) {
  ConfigParser p;
  ConfigTable *conf = config_parse(&p, "./example.config");
  if(!conf) {
    // Parsing failed.
    return EXIT_FAILURE;
  }
  
  // Reading top-level pairs:
  ConfigValue val = config_get_boolean(conf, "is_day");
  if(val.ok) {
    printf("it is %s\n", val.as.boolean ? "day" : "night");
  }
  
  // Getting a table:
  ConfigTable *joe = config_get_table(&p, "Joe");
  if(!joe) {
    return EXIT_FAILURE;
  }
  
  // Reading the pairs in the table:
  int age = 0;
  val = config_get_number(joe, "age");
  if(val.ok) {
    age = val.as.number;
  }

  val = config_get_string(joe, "favorite_food");
  if(val.ok) {
    printf("Joe is %d years old and his favorite food is %s\n", age, val.as.string);
  }
  
  config_end(&p);
  return EXIT_SUCCESS;
}

The state of the parser is stored in the ConfigParser struct. The config_parse() function initializes it and stores the parsed configuration file in it. All the data is owned by the ConfigParser struct and is freed when config_end() is called.

A configuration file is represented as a table containing all the pairs, the tables are stored in the ConfigParser struct and can accessed using config_get_table().

The following functions are used to get a value from a table.
They return a ConfigValue that has an ok boolean field and a union containing all the possible value types.
If ok is true, the value is valid and can be accessed. it is important to use the correct field in the as union.

ConfigValue config_get_string(ConfigTable *t, const char *key);
ConfigValue config_get_number(ConfigTable *t, const char *key);
ConfigValue config_get_boolean(ConfigTable *t, const char *key);