toml/tomlc99/README.md

# tomlc99

TOML in c99; v1.0 compliant.

If you are looking for a C++ library, you might try this wrapper: [https://github.com/cktan/tomlcpp](https://github.com/cktan/tomlcpp).

* Compatible with [TOML v1.0.0](https://toml.io/en/v1.0.0).
* Tested with multiple test suites, including
[toml-lang/toml-test](https://github.com/toml-lang/toml-test) and
[iarna/toml-spec-tests](https://github.com/iarna/toml-spec-tests).
* Provides very simple and intuitive interface.


## Usage

Please see the `toml.h` file for details. The following is a simple example that
parses this config file:

```toml
[server]
	host = "www.example.com"
	port = [ 8080, 8181, 8282 ]
```

These are the usual steps for getting values from a file:

1. Parse the TOML file.
2. Traverse and locate a table in TOML.
3. Extract values from the table.
4. Free up allocated memory.

Below is an example of parsing the values from the example table.

```c
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include "toml.h"

static void error(const char* msg, const char* msg1)
{
    fprintf(stderr, "ERROR: %s%s\n", msg, msg1?msg1:"");
    exit(1);
}


int main()
{
    FILE* fp;
    char errbuf[200];

    // 1. Read and parse toml file
    fp = fopen("sample.toml", "r");
    if (!fp) {
        error("cannot open sample.toml - ", strerror(errno));
    }

    toml_table_t* conf = toml_parse_file(fp, errbuf, sizeof(errbuf));
    fclose(fp);

    if (!conf) {
        error("cannot parse - ", errbuf);
    }

    // 2. Traverse to a table.
    toml_table_t* server = toml_table_in(conf, "server");
    if (!server) {
        error("missing [server]", "");
    }

    // 3. Extract values
    toml_datum_t host = toml_string_in(server, "host");
    if (!host.ok) {
        error("cannot read server.host", "");
    }

    toml_array_t* portarray = toml_array_in(server, "port");
    if (!portarray) {
        error("cannot read server.port", "");
    }

    printf("host: %s\n", host.u.s);
    printf("port: ");
    for (int i = 0; ; i++) {
        toml_datum_t port = toml_int_at(portarray, i);
        if (!port.ok) break;
        printf("%d ", (int)port.u.i);
    }
    printf("\n");

    // 4. Free memory
    free(host.u.s);
    toml_free(conf);
    return 0;
}
```

#### Accessing Table Content

TOML tables are dictionaries where lookups are done using string keys. In
general, all access functions on tables are named `toml_*_in(...)`.

In the normal case, you know the key and its content type, and retrievals can be done
using one of these functions:
```c
toml_string_in(tab, key);
toml_bool_in(tab, key);
toml_int_in(tab, key);
toml_double_in(tab, key);
toml_timestamp_in(tab, key);
toml_table_in(tab, key);
toml_array_in(tab, key);
```

You can also interrogate the keys in a table using an integer index:
```c
toml_table_t* tab = toml_parse_file(...);
for (int i = 0; ; i++) {
    const char* key = toml_key_in(tab, i);
    if (!key) break;
    printf("key %d: %s\n", i, key);
}
```

#### Accessing Array Content

TOML arrays can be deref-ed using integer indices. In general, all access methods on arrays are named `toml_*_at()`.

To obtain the size of an array:
```c
int size = toml_array_nelem(arr);
```

To obtain the content of an array, use a valid index and call one of these functions:
```c
toml_string_at(arr, idx);
toml_bool_at(arr, idx);
toml_int_at(arr, idx);
toml_double_at(arr, idx);
toml_timestamp_at(arr, idx);
toml_table_at(arr, idx);
toml_array_at(arr, idx);
```

#### toml_datum_t

Some `toml_*_at` and `toml_*_in` functions return a toml_datum_t
structure. The `ok` flag in the structure indicates if the function
call was successful. If so, you may proceed to read the value
corresponding to the type of the content.

For example:
```
toml_datum_t host = toml_string_in(tab, "host");
if (host.ok) {
	printf("host: %s\n", host.u.s);
	free(host.u.s);   /* FREE applies to string and timestamp types only */
}
```

** IMPORTANT: if the accessed value is a string or a timestamp, you must call `free(datum.u.s)` or `free(datum.u.ts)` respectively after usage. **

## Building and installing

A normal *make* suffices. You can also simply include the
`toml.c` and `toml.h` files in your project.

Invoking `make install` will install the header and library files into
/usr/local/{include,lib}.

Alternatively, specify `make install prefix=/a/file/path` to install into
/a/file/path/{include,lib}.

## Testing

To test against the standard test set provided by toml-lang/toml-test:

```sh
% make
% cd test1
% bash build.sh   # do this once
% bash run.sh     # this will run the test suite
```


To test against the standard test set provided by iarna/toml:

```sh
% make
% cd test2
% bash build.sh   # do this once
% bash run.sh     # this will run the test suite
```