config

Config is a simple library for parsing configuration files.

# This is a configuration file

KEY = VALUE                 # This is an example setting
My\=Setting = Potato = Food # You can escape the delimiter

# You can even have custom delimiters
OUTPUT:c++

Install

Unix-like systems (macOS, Linux, etc.)

git clone https://github.com/ethanuppal/config \
    && cd config \
    && make install

This command will install the static (libconfig.a) and dynamic (libconfig.so) libraries in /usr/local/lib and the header file <config/config.h> in /usr/local/include.

Run make uninstall to uninstall the library.

Windows

If you have clang and make installed, you can run the following commands in bash or similar:

git clone https://github.com/ethanuppal/config \
    && cd config \
    && make all

This will build the static and dynamic libraries in the current directory.

Usage

Section contents

• Example
• Callback
• Parsing files
• Configuring config

Example

The directory test/ has a working example with:

• config.txt: A sample configuation file
• main.c: A program that uses config to parse it

Callback

Create a callback for when config finds a new variable as follows (in order that it be of type conf_parse_handler_t). The parameters besides user_data are read-only and valid for only as long as config is parsing, so be sure to copy them if you want to use it outside of the callback.

void callback(const char *var, const char *data, void *user_data) {
    myapi_t *api = (myapi_t*)user_data;
    if (strcmp(var, "PATH") == 0) {
        api->path = data;
    }
}

Then call conf_parse_file or conf_parse_text with the appropriate arguments.

Parsing files

conf_parse_file

int conf_parse_file(FILE* f, conf_parse_handler_t handler, void* user_data);

Parses the given file as a configuration file.

Param	Description
f	The configution file handle.
handler	The callback for when a variable is found.
user_data	Optional data passed to the callback.

conf_parse_text

int conf_parse_text(const char* s, conf_parse_handler_t handler, void* user_data);

Parses the given text as a configuation file.

Param	Description
s	A string in config syntax.
handler	The callback for when a variable is found.
user_data	Optional data passed to the callback.

Configuring config

conf_set_comments

void conf_set_comments(const char* comments);

Tells config what comments look like.

Param	Description
comments	A list of characters. Any line starting with these characters will be ignores. Empty lines are automatically ignored.

If this function is not invoked, config will behave as if it was run as

conf_set_comments("\n#");

Example:

// Ignore lines starting with, spaces, tabs, exclamation points, and hashtags.
conf_set_comments(" \t#!");

conf_set_delimiters

void conf_set_delimiters(const char* delimiters, char escape);

Tells config what the variable delimiters look like.

Param	Description
delimiters	A list of variable delimiters.
escape	An optional escape character. Set this to 0 if you don't want any escaping. If specified, variable names can include a delimiter character provided it is prefixed with the escape character. It will show up in the callback without the escape. A sequence of two escape characters will show up as a single one.

If this function is not invoked, config will behave as if it was run as

conf_set_delimiters("=", '\\');

Example 1:

// Variables defined with '=', escapes with '\'
conf_set_delimiters("=", '\\');

Example 2:

// Variables defined with ':', no escaping
conf_set_delimiters(":", 0);

conf_set_trimming

void conf_set_trimming(const char* whitespace);

Tells config whether to trim leading and trailing whitespace from entries.

Param	Description
whitespace	A list of characters to trim. If this value is NULL, trimming is disabled.

If this function is not invoked, config will behave as if it was run as

conf_set_trimming(" \t");

Example:

// Disable trimming
conf_set_trimming(NULL);