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Undefined Reference Error In Linux

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Below is the make output. /home/mark/dev/static/nanomsg_origin/src/transports/utils/dns_getaddrinfo_a.inc:119: undefined reference to `getaddrinfo_a' /home/mark/dev/app/usr/lib/libnanomsg.a(dns.o): In function `nn_dns_notify': /home/mark/dev/static/nanomsg_origin/src/transports/utils/dns_getaddrinfo_a.inc:139: undefined reference to `gai_error' /home/mark/dev/app/usr/lib/libnanomsg.a(dns.o): In function `nn_dns_shutdown': /home/mark/dev/static/nanomsg_origin/src/transports/utils/dns_getaddrinfo_a.inc:169: undefined reference to `gai_cancel' collect2: error: ld It's designed to be run to test the library so it doesn't matter as long as it works after it has been built. –Matthew Mitchell Sep 5 '12 at 0:13 Build usually is done in two steps (1) compilation and (2) linking. Join them; it only takes a minute: Sign up In C programming, what is `undefined reference`error, when compiling? [duplicate] up vote 5 down vote favorite 1 This question already has an weblink

User contributions on this site are licensed under the Creative Commons Attribution Share Alike 4.0 International License. Integer function which takes every value infinitely often Origin of “can” in the sense of ‘jail’ What was the first operating system to feature a separate kernel? Ask Ubuntu works best with JavaScript enabled Skip to content Ignore Learn more Please note that GitHub no longer supports old versions of Firefox. There are any number of reasons why it can’t find the definition – we’ll look at the commonest ones now. http://stackoverflow.com/questions/12272864/linker-error-on-linux-undefined-reference-to

Undefined Reference To Function In C

Moreover, if a program calc.c requires the math library, I need to specify the compiling command line as (in the webpage): $ gcc –Wall calc.c –lm –o calc to ensure that internal is defined within the object but invisible from the outside. As it seems it happens with every library in any path because i checked different cases also. I ran into "undefined reference to" error.

What would have happened to the world if the sepoy mutiny of 1857 had suceeded? Rate this:Like this:Like Loading... Right now i am using gcc Main.c -o Main –dimitris93 May 2 '15 at 4:49 2 @Shiro gcc Main.c Person.c -o Main –user3528438 May 2 '15 at 4:52 Undefined Reference To Linker Error Given a limit with notation f, how would you solve?

Note that since these are object files, the linking order does not matter. Gcc Linker Error Undefined Reference Here is the link: http://userver.ftw.at/~pucher/semanlm/semanlm0.91.zip if it is useful. and so on. Visit Website The compiler needs a class definition.

index is set to the corresponding * index. * * unsigned int read(File &file) * Read a word list from a file into the Vocab, implicitly performing * an addWord() on C Undefined Reference To Pthread_create For bigger projects, the two step process allows to compile only what changed during the generation of the executable. As long as you keep it in mind, linker errors and related problems should be easy to understand. Check out this tutorial on makefiles: Make File Tutorial It helps to automate this process.

  1. That's why I quoted the list you had of them, with only one file in it.
  2. I mean one of the errors get lost.
  3. Linker 101 To understand the linker, you have to understand how C++ programs are built.
  4. Linking is already a critical part of the compilation time of large systems, since it looks at the whole program and requires quite a bit of memory.

Gcc Linker Error Undefined Reference

Even if it exports symbols that may be needed by some later library. https://github.com/nanomsg/nanomsg/issues/213 This was just to get one of the tests to work (pipeline.c). Undefined Reference To Function In C main_using_memcpy.o -lstray_memcpy $ ./a.out Segmentation fault (core dumped) This is the expected behavior. Undefined Reference To A Function C++ How to create a custom theme in SXA?

OpenSSL too: /media/sf_BitEagle_Projects/cbitcoin/dependencies/crypto/CBOpenSSLCrypto.c:37: undefined reference to `SHA1' How do I get the linking to work? have a peek at these guys If we link them in one order, we fail: $ gcc simplemain.o -L. -lbar_dep -lfunc_dep ./libfunc_dep.a(func_dep.o): In function 'func': func_dep.c:(.text+0x14): undefined reference to 'bar' collect2: ld returned 1 exit status However, When the linker encounters libsimplefunc.a, it still hasn't seen simplemain.o, which means that func is not yet on the undefined list. Why is the size of my email so much bigger than the size of its attached files? Undefined Reference To Gcc

But AA can't come both before and after BB on the command-line, right? So, for example if the only C standard library function your code uses is strlen, only strlen.o will be taken into the link from libc.a - and your executable will be Why do the Sparkfun and Adafruit Eagle libraries use smaller footprints than the manufacturer's recommended land pattern? check over here For example, if the code above we had provided a definition of foo() that looked like this: int foo(int n) { return n; } then we would still get an error

When the linker does reach simplemain.o and sees that func is, indeed required, it's added to the undefined list (because it's not on the exported list). C Undefined Reference To Function In Header File share|improve this answer answered May 2 '15 at 4:55 Mlagma 694932 add a comment| Not the answer you're looking for? The compiler will spit out object files that will later be linked into an executable.

No Definition Probably the most common reason for unresolved reference errors is that you simply have not defined the thing you are referencing.

NewbiZ commented Mar 5, 2014 Rerun configure and reinstall nanomsg with the following patch to libnanomsg.pc.in. but It takes a while to me to understand it. If any symbols remain in the undefined list, the linker will throw an "undefined reference" error. Undefined Reference C++ So we get the error (slightly edited for clarity): a.cpp:(.text+0xc): undefined reference to `foo()' error: ld returned 1 exit status The way to fix it is to provide the definition: int

I write this command to see the errors "make > make.txt 2>&1" and it prints the process to make.txt and the errors are the same. When the linker looks into the library it sees simplefunc.o that exports func. Running gcc -o test test.c brings no error and afterwards I can run the program test with ./test. http://centralpedia.com/undefined-reference/undefined-reference-to-ns2-error.html If two topological spaces have the same topological properties, are they homeomorphic?

If any symbol has already been in the exported list, we get a "multiple definition" error: two different objects export the same symbol and the linker is confused. May 2 '15 at 6:05 This question has been asked before and already has an answer. When the linker encounters a new object file, it looks at: The symbols it exports: these are added to the list of exported symbols mentioned above. test.c #include main() { printf("Linuxquestions.org\n"); } so it seems I did something correct.

I have been for many years now. Otherwise, read on. And linkers do not necessarily have access to the source code for the object files they are linking. When I look in common.h I find int initLog(int useSyslog, char *logfile,int debugSwitch); and looking in common.c (also in the same directory) I find int initLog(int useSyslog, char *logfile,int debugSwitch) {

Yes you are right. Jul 7, 2008 at 5:13am UTC pardis (5) hi Thank you all so much for you answers. But when I try to compile the file that I really want to use "vclient.c" I get an error message /tmp/ccuuPxtN.o(.text+0x3bc): In function `main': vclient.c: undefined reference to `initLog' Now as If those answers do not fully address your question, please ask a new question. @Satya uh, why ?

Forum Today's Posts C and C++ FAQ Forum Actions Mark Forums Read Quick Links View Forum Leaders What's New? It's never to late to learn GNU `make' Hopefully you know something about programming and compiling... The Finslerian version of the Nash embedding theorem more hot questions lang-c about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology It just tells the compiler that the class exists, it doesn't tell the compiler anything about it.

Check that your PKG_CONFIG_PATH contains the path where libnanomsg.pc will be dropped (usuallly $prefix/lib/pkgconfig) Check in $prefix/lib/pkgconfig/libnanomsg.pc that the proper -lanl flag was added to Libs and -pthread to Cflags. How to create a custom theme in SXA?