我正在使用g ++。
代码:
std::string str = "{\"action\":3,\"data\":{\"account\":\"somehashgoeshear\",\"someint\":0,\"id\":1,\"moreint\":0,\"name\":\"demo\"}}";
char *cstr = strdup(str.c_str());
lwsl_notice("\n%s", cstr);
return lws_write(wsi, (unsigned char*)cstr, strlen(cstr), LWS_WRITE_TEXT);
这也不起作用:
std::string str = "{\"action\":3,\"data\":{\"account\":\"somehashgoeshear\",\"someint\":0,\"id\":1,\"moreint\":0,\"name\":\"demo\"}}";
return lws_write(wsi, (unsigned char*)str.c_str(), strlen(str.c_str()), LWS_WRITE_TEXT);
但是这很好(可以运行很多次而不会出现错误):
char cstr[96] = "{\"action\":3,\"data\":{\"account\":\"somehashgoeshear\",\"someint\":0,\"id\":1,\"moreint\":0,\"name\":\"demo\"}}";
return lws_write(wsi, (unsigned char*)cstr, strlen(cstr), LWS_WRITE_TEXT);
也尝试过使用malloc
创建字符串,但这也不起作用:
std::string str = "{\"action\":3,\"data\":{\"account\":\"somehashgoeshear\",\"someint\":0,\"id\":1,\"moreint\":0,\"name\":\"demo\"}}";
char *cstr = (char *)malloc((str.length() + 1) * sizeof(char));
strcpy(cstr, str.c_str());
lwsl_notice("\n%s", cstr);
return lws_write(wsi, (unsigned char*)cstr, strlen(cstr), LWS_WRITE_TEXT);
我可以多次运行此代码,但最终我遇到此错误:free(): invalid next size (fast)
(发送数据后失败)
[我也尝试了LWS_PRE
的耦合实验,但是当我将其添加到字符串时,它在消息开头添加了几个符号,例如:a":
[发送数据后尝试free(cstr)
时,它立即失败,并显示double free or corruption (out)
错误。
lws版本:1.7.1os:ubuntu x64
重要提示!
使用websocket协议发送时
LWS_WRITE_TEXT,LWS_WRITE_BINARY,LWS_WRITE_CONTINUATION,LWS_WRITE_PING,LWS_WRITE_PONG,
或通过http / 2发送,
发送缓冲区之前,发送缓冲区必须具有有效的LWS_PRE字节您传递给lws_write()的指针。
这意味着您必须为缓冲区分配额外的LWS_PRE字节,即
std::string str(LWS_PRE, ' '); //Allocate LWS_PRE bytes
str += "{\"action\":3,\"data\":{\"account\":\"somehashgoeshear\",\"someint\":0,\"id\":1,\"moreint\":0,\"name\":\"demo\"}}"
return lws_write(wsi, (unsigned char*)&str[LWS_PRE], strlen(str.c_str()), LWS_WRITE_TEXT);