c++ - Including libraries in G++ using -l confusion -


i'm trying use external library i'm confused how fits together.

i have following code i'm trying compiled:

#include "cryptopp/sha.h"  int main() {     cryptopp::sha1 sha1;     return 0; }

i'm using g++ compiling, , research i've gathered need append 

-lcryptopp

to end of compile command so:

g++ crypto.cpp -o crypto.exe -lcryptopp

but following error:

/usr/lib/gcc/x86_64-pc-cygwin/4.9.3/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lcryptopp

this confused, i'm not sure -lcryptopp looking for, looking sha.cpp/sha.h files i'm including in code? more importantly how specify whatever it's looking want in cryptopp folder in same folder main .cpp?

-lcryptopp tells linker link exe against dynamic library (shared object) file libcryptopp.so. gnu linker searches shared object files in various directories /lib, /usr/lib , others.

you can specify additional directories search library files -l option, -l/usr/local/lib. should find out library file libcryptopp.so located , pass path -l option.


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