在Go语言项目中，常用的配置文件yaml、toml、json、xml、ini几种，因为本章主要讲解yaml配置文件的使用方法，其他几种配置文件在这里就不展开了介绍了，大家有兴趣可以自行百度。
yaml文件的语法网上有很多的教程，大家自行百度，这里也推荐两个链接：
yaml文件解析使用的是github上第三方开源框架 gopkg.in/yaml.v2 ，下面详细介绍安装和使用的方法：
参考链接： https://blog.csdn.net/wade3015/article/details/83351776
在go语言中使用viper之类的库很方便的处理yaml配置文件，但是在c语言中就比较麻烦，经过一番思索和借助强大的github,发现了一个libyaml c库，但是网上的例子都比较麻烦，而且比较繁琐，就想法作了一个相对比较容易配置的解析应用，可以简单地类似viper 的模式进行配置实现不同的配置文件读取。如你的配置文件很复杂请按格式修改KeyValue 全局变量，欢迎大家一起完善
库请自行下载 GitHub - yaml/libyaml: Canonical source repository for LibYAML
直接上代码
yaml示例文件
%YAML 1.1
---
mqtt:
subtopic: "Control/#"
pubtopic: "bbt"
qos: 1
serveraddress: "tcp://192.168.0.25:1883"
clientid: "kvm_test"
writelog: false
writetodisk: false
outputfile: "./receivedMessages.txt"
hearttime: 30
#ifndef __CONFIG_H__
#define __CONFIG_H__
#ifdef __cplusplus
extern "C" {
#endif
/************************/
/* Minimum YAML version */
/************************/
#define YAML_VERSION_MAJOR 1
#define YAML_VERSION_MINOR 1
#define STRUCT_TYPE_NAME 100
#define INT_TYPE_NAME 101
#define STRING_TYPE_NAME 102
#define BOOL_TYPE_NAME 103
#define FLOAT_TYPE_NAME 104
#define MAP_TYPE_NAME 105
#define LIST_TYPE_NAME 106
typedef struct{
char *key
void *value
int valuetype
char *parent
}KeyValue,*pKeyValue
#ifdef __cplusplus
}
#endif
#endif
#include
#include
#include
#include
#include
#include
#include
#include "config.h"
typedef struct {
char *SUBTOPIC//string `yaml:"subtopic" mapstructure:"subtopic"` //"topic1"
char *PUBTOPIC//string `yaml:"pubtopic" mapstructure:"pubtopic"`
int QOS//byte `yaml:"qos" mapstructure:"qos"` //1
char *SERVERADDRESS//string `yaml:"serveraddress" mapstructure:"serveraddress"` //= "tcp://mosquitto:1883"
char *CLIENTID//string `yaml:"clientid" mapstructure:"clientid"` //= "mqtt_subscriber"
int HEARTTIME//int `yaml:"hearttime" mapstructure:"hearttime"`
// CommandLocalPath string `yam:"commanlocalpath"`
}mqttSection,*pmqttSection
typedef struct {
mqttSection Mqtt// `yaml:"mqtt" mapstructure:"mqtt"`
// KVM kvmSection `yaml:"kvm" mapstructure:"kvm"`
}ConfigT
ConfigT config
static KeyValue webrtcconfig[]={
{"mqtt",&config,STRUCT_TYPE_NAME,NULL},
{"subtopic",&(config.Mqtt.SUBTOPIC),STRING_TYPE_NAME,"mqtt"},
{"pubtopic",&(config.Mqtt.PUBTOPIC),STRING_TYPE_NAME,"mqtt"},
{"qos",&(config.Mqtt.QOS),INT_TYPE_NAME,"mqtt"},
{"serveraddress",&(config.Mqtt.SERVERADDRESS),STRING_TYPE_NAME,"mqtt"},
{"clientid",&(config.Mqtt.CLIENTID),STRING_TYPE_NAME,"mqtt"},
{"hearttime",&(config.Mqtt.HEARTTIME),INT_TYPE_NAME,"mqtt"},
{NULL,NULL,0,NULL},
}
int printConfig(ConfigT * pconfig){
if(pconfig==NULL) return -1
printf("mqtt:r ")
if(pconfig->Mqtt.SUBTOPIC!=NULL) {printf("subtopic: %sr ",pconfig->Mqtt.SUBTOPIC)}
if(pconfig->Mqtt.SUBTOPIC!=NULL) {printf("pubtopic: %sr ",pconfig->Mqtt.PUBTOPIC)}
printf("qos: %dr ",config.Mqtt.QOS)
if(pconfig->Mqtt.SERVERADDRESS!=NULL) {printf("serveraddress: %sr ",pconfig->Mqtt.SERVERADDRESS)}
if(pconfig->Mqtt.CLIENTID!=NULL) {printf("clientid: %sr ",pconfig->Mqtt.CLIENTID)}
printf("hearttime: %dr ",config.Mqtt.HEARTTIME)
}
int freeConfig(ConfigT * pconfig){
if(pconfig==NULL) return -1
if(pconfig->Mqtt.SERVERADDRESS!=NULL) {free(pconfig->Mqtt.SERVERADDRESS)}
if(pconfig->Mqtt.CLIENTID!=NULL) {free(pconfig->Mqtt.CLIENTID)}
if(pconfig->Mqtt.SUBTOPIC!=NULL) {free(pconfig->Mqtt.SUBTOPIC)}
}
char currentkey[100]
void getvalue(yaml_event_t event,pKeyValue *ppconfigs){
char *value = (char *)event.data.scalar.value
pKeyValue pconfig=*ppconfigs
char *pstringname
while(pconfig->key!=NULL){
if(currentkey[0]!=0){
if(!strcmp(currentkey,pconfig->key))
{
switch(pconfig->valuetype){
case STRING_TYPE_NAME:
pstringname=strdup(value)
printf("get string value %sr ",pstringname)
*((char**)pconfig->value)=pstringname
memset(currentkey, 0, sizeof(currentkey))
break
case INT_TYPE_NAME:
*((int*)(pconfig->value))=atoi(value)
memset(currentkey, 0, sizeof(currentkey))
break
case BOOL_TYPE_NAME:
if(!strcmp(value,"true")) *((bool*)(pconfig->value))=true
else *((bool*)(pconfig->value))=false
memset(currentkey, 0, sizeof(currentkey))
break
case FLOAT_TYPE_NAME:
*((float*)(pconfig->value))=atof(value)
memset(currentkey, 0, sizeof(currentkey))
break
case STRUCT_TYPE_NAME:
case MAP_TYPE_NAME:
case LIST_TYPE_NAME:
memset(currentkey, 0, sizeof(currentkey))
strncpy(currentkey,value,strlen(value))
break
default:
break
}
break
}
//continue
}else{
if(!strcmp(value,pconfig->key)){
strncpy(currentkey,pconfig->key,strlen(pconfig->key))
break
}
}
pconfig++
}
}
int Load_YAML_Config( char *yaml_file, KeyValue *(configs[]) )
{
struct stat filecheck
yaml_parser_t parser
yaml_event_t event
bool done = 0
unsigned char type = 0
unsigned char sub_type = 0
if (stat(yaml_file, &filecheck) != false )
{
printf("[%s, line %d] Cannot open configuration file '%s'! %s", __FILE__, __LINE__, yaml_file, strerror(errno) )
return -1
}
FILE *fh = fopen(yaml_file, "r")
if (!yaml_parser_initialize(&parser))
{
printf("[%s, line %d] Failed to initialize the libyaml parser. Abort!", __FILE__, __LINE__)
return -1
}
if (fh == NULL)
{
printf("[%s, line %d] Failed to open the configuration file '%s' Abort!", __FILE__, __LINE__, yaml_file)
return -1
}
memset(currentkey, 0, sizeof(currentkey))
/* Set input file */
yaml_parser_set_input_file(&parser, fh)
while(!done)
{
if (!yaml_parser_parse(&parser, &event))
{
/* Useful YAML vars: parser.context_mark.line+1, parser.context_mark.column+1, parser.problem, parser.problem_mark.line+1, parser.problem_mark.column+1 */
printf( "[%s, line %d] libyam parse error at line %ld in '%s'", __FILE__, __LINE__, parser.problem_mark.line+1, yaml_file)
}
if ( event.type == YAML_DOCUMENT_START_EVENT )
{
//yaml file first line is version
//%YAML 1.1
//---
yaml_version_directive_t *ver = event.data.document_start.version_directive
if ( ver == NULL )
{
printf( "[%s, line %d] Invalid configuration file. Configuration must start with "%%YAML 1.1"", __FILE__, __LINE__)
}
int major = ver->major
int minor = ver->minor
if (! (major == YAML_VERSION_MAJOR &&minor == YAML_VERSION_MINOR) )
{
printf( "[%s, line %d] Configuration has a invalid YAML version. Must be 1.1 or above", __FILE__, __LINE__)
return -1
}
}
else if ( event.type == YAML_STREAM_END_EVENT )
{
done = true
}
else if ( event.type == YAML_MAPPING_END_EVENT )
{
sub_type = 0
}
else if ( event.type == YAML_SCALAR_EVENT )
{
getvalue(event,configs)
}
}
return 0
}
int main(int argc, char *argv[]){
pKeyValue pconfig=&webrtcconfig[0]
Load_YAML_Config("../../etc/kvmagent.yml",&pconfig)
printConfig(&config)
freeConfig(&config)
}
当一个项目中有多个yml配置文件的时候，可以以application-**.yml命名；在application.yml中配置项目使用激活这些配置文件即可。多个文件名只需要写application-之后的名称，在多个文件之间使用,隔开。在两个配置文件中如果存在同名的配置项的话会以properties文件的为主。激活配置文件application-a.yml与application-b.yml
