pollymc/libraries/tomlc99/README.md

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2021-04-17 22:16:11 +05:30
# 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
[BurntSushi/toml-test](https://github.com/BurntSushi/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. What follows is a simple example that
parses this config file:
```toml
[server]
host = "www.example.com"
port = [ 8080, 8181, 8282 ]
```
The steps for getting values from our file is usually :
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 BurntSushi/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
```