198 lines
4.7 KiB
Markdown
198 lines
4.7 KiB
Markdown
# tomlc99
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TOML in c99; v1.0 compliant.
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If you are looking for a C++ library, you might try this wrapper: [https://github.com/cktan/tomlcpp](https://github.com/cktan/tomlcpp).
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* Compatible with [TOML v1.0.0](https://toml.io/en/v1.0.0).
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* Tested with multiple test suites, including
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[BurntSushi/toml-test](https://github.com/BurntSushi/toml-test) and
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[iarna/toml-spec-tests](https://github.com/iarna/toml-spec-tests).
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* Provides very simple and intuitive interface.
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## Usage
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Please see the `toml.h` file for details. What follows is a simple example that
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parses this config file:
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```toml
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[server]
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host = "www.example.com"
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port = [ 8080, 8181, 8282 ]
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```
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The steps for getting values from our file is usually :
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1. Parse the TOML file.
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2. Traverse and locate a table in TOML.
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3. Extract values from the table.
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4. Free up allocated memory.
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Below is an example of parsing the values from the example table.
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```c
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <stdlib.h>
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#include "toml.h"
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static void error(const char* msg, const char* msg1)
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{
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fprintf(stderr, "ERROR: %s%s\n", msg, msg1?msg1:"");
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exit(1);
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}
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int main()
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{
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FILE* fp;
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char errbuf[200];
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// 1. Read and parse toml file
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fp = fopen("sample.toml", "r");
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if (!fp) {
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error("cannot open sample.toml - ", strerror(errno));
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}
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toml_table_t* conf = toml_parse_file(fp, errbuf, sizeof(errbuf));
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fclose(fp);
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if (!conf) {
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error("cannot parse - ", errbuf);
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}
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// 2. Traverse to a table.
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toml_table_t* server = toml_table_in(conf, "server");
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if (!server) {
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error("missing [server]", "");
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}
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// 3. Extract values
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toml_datum_t host = toml_string_in(server, "host");
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if (!host.ok) {
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error("cannot read server.host", "");
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}
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toml_array_t* portarray = toml_array_in(server, "port");
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if (!portarray) {
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error("cannot read server.port", "");
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}
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printf("host: %s\n", host.u.s);
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printf("port: ");
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for (int i = 0; ; i++) {
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toml_datum_t port = toml_int_at(portarray, i);
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if (!port.ok) break;
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printf("%d ", (int)port.u.i);
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}
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printf("\n");
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// 4. Free memory
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free(host.u.s);
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toml_free(conf);
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return 0;
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}
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```
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#### Accessing Table Content
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TOML tables are dictionaries where lookups are done using string keys. In
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general, all access functions on tables are named `toml_*_in(...)`.
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In the normal case, you know the key and its content type, and retrievals can be done
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using one of these functions:
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```c
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toml_string_in(tab, key);
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toml_bool_in(tab, key);
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toml_int_in(tab, key);
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toml_double_in(tab, key);
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toml_timestamp_in(tab, key);
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toml_table_in(tab, key);
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toml_array_in(tab, key);
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```
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You can also interrogate the keys in a table using an integer index:
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```c
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toml_table_t* tab = toml_parse_file(...);
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for (int i = 0; ; i++) {
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const char* key = toml_key_in(tab, i);
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if (!key) break;
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printf("key %d: %s\n", i, key);
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}
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```
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#### Accessing Array Content
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TOML arrays can be deref-ed using integer indices. In general, all access methods on arrays are named `toml_*_at()`.
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To obtain the size of an array:
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```c
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int size = toml_array_nelem(arr);
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```
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To obtain the content of an array, use a valid index and call one of these functions:
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```c
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toml_string_at(arr, idx);
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toml_bool_at(arr, idx);
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toml_int_at(arr, idx);
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toml_double_at(arr, idx);
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toml_timestamp_at(arr, idx);
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toml_table_at(arr, idx);
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toml_array_at(arr, idx);
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```
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#### toml_datum_t
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Some `toml_*_at` and `toml_*_in` functions return a toml_datum_t
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structure. The `ok` flag in the structure indicates if the function
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call was successful. If so, you may proceed to read the value
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corresponding to the type of the content.
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For example:
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```c
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toml_datum_t host = toml_string_in(tab, "host");
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if (host.ok) {
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printf("host: %s\n", host.u.s);
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free(host.u.s); /* FREE applies to string and timestamp types only */
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}
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```
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**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.**
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## Building and installing
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A normal *make* suffices. You can also simply include the
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`toml.c` and `toml.h` files in your project.
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Invoking `make install` will install the header and library files into
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/usr/local/{include,lib}.
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Alternatively, specify `make install prefix=/a/file/path` to install into
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/a/file/path/{include,lib}.
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## Testing
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To test against the standard test set provided by BurntSushi/toml-test:
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```sh
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% make
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% cd test1
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% bash build.sh # do this once
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% bash run.sh # this will run the test suite
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```
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To test against the standard test set provided by iarna/toml:
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```sh
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% make
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% cd test2
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% bash build.sh # do this once
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% bash run.sh # this will run the test suite
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```
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