Error during complie

[HuangFeiY]

I try to use ubuntu 20.04 to run this software.
I first use command below and install libcurl successfully.

sudo apt-get install libcurl4-openssl-dev 

However, when I try to compile the program using command below, an error occur

g++ -std=gnu++11 -lcurl idsEventGenerator.cpp

My g++ version is 9.4.0

And the detail information:

/usr/bin/ld: /tmp/cc9j7hq0.o: in function `sendRulePacket(snortRule*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool)':
idsEventGenerator.cpp:(.text+0x502f): undefined reference to `curl_global_init'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x5034): undefined reference to `curl_easy_init'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x51b3): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x51d1): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x51ef): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x520d): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x5223): undefined reference to `curl_slist_append'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x5240): undefined reference to `curl_slist_append'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x5364): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x53bb): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x5405): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x556f): undefined reference to `curl_slist_append'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x6121): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x615e): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x618e): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x634b): undefined reference to `curl_slist_append'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x65f1): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x6694): undefined reference to `curl_slist_append'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x66bb): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x66e6): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x672b): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x6752): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x6770): undefined reference to `curl_easy_setopt'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x677f): undefined reference to `curl_easy_perform'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x679b): undefined reference to `curl_easy_strerror'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x6809): undefined reference to `curl_easy_getinfo'
/usr/bin/ld: idsEventGenerator.cpp:(.text+0x6850): undefined reference to `curl_easy_cleanup'
collect2: error: ld returned 1 exit status

I'm confused and try to ask for solution.