I am trying to compile my C socket programming files using gcc with -lnsl option on MAC OS but it gives me this error:
ld: library not found for -lnsl
clang: error: linker command failed with exit code 1 (use -v to see
invocation)
This is the gcc command:
gcc -o server -lnsl server.c
I looked all over the internet but I can't find sth relevant to help me. How to install the missing library? Or should I reinstall gcc? Please help!
Thanks!
Mac OS X has no libnsl. Functions that live in libnsl on Linux are found in the standard C library on Mac OS X. No additional flags are necessary for building programs that use these functions.
If your program works on Linux and doesn't work on a Mac, then your program has a bug that is triggered on Mac OS X but not on Linux. No amout of fiddling with linker flags is likely to change that.
Related
I'm doing a university assignment on shared memory on C, I need to use the functions shm_open(), mmap(), ftruncate(), shm_unlink(), etc. using a Mac with macOS Mojave 10.14
My teacher told me I need to use the -lrt library in my Makefile to make it work but when I "make" I got an error which goes
ld: library not found for -lrt
clang: error: linker command failed with exit code 1
Is the library spelled work? If I don't have it, I need to download it? Do I even need a specific library? ('cause on the internet I didn't find anybody using one...)
I'm very confused.
i'm getting some troubles with QT it builds with option "-lrt"
i'm using mac os 10.6 with QT creator 1.2.1, heeeeeeelp !
this is the full build command :
g++ -headerpad_max_install_names -o
AMiningCoreTest main.o tokenizer.o
DictionnaryToolBox.o mysql.o btree.o
BTreeDataTable.o tcaccess.o
-L/Library/Frameworks -L/usr/lib/mysql -lmysqlclient -L/usr/local/lib/ -ltokyocabinet -lz -lbz2 -lrt -lpthread -lm -lc
and it ends with
ld: library not found for -lrt
collect2: ld returned 1 exit status
The linker cannot find librt which is probably the Posix real time extensions library. I don't think this is available on OSX. Googling gives this from Apple developer lists
Question from list
I'm trying to build a simulator developed in my university (on Linux)
and I get error by the linker that seems unable to find librt.a - in
the code is used for clock_gettime() and I would like to know if
there's a port of such library, or some other similar function that
allows me to compile even on Mac OS X.
Answer
librt.a is the System V name of the library containing the POSIX
Advanced Realtime [RT} Option functions. The specific function you are
asking about is part of the [TMR] option. If Mac OS X supported it, it
would be in libSystem.B,dylib, not librt.a. The function in question
is not supported by Mac OS X.
Your code should check to see whether optional to implement things
above and beyond the UNIX standard are implemented in the target OS,
and if they aren't, use a different interface.
Why does the program need librt?
I know that some platforms (Solaris comes to mind) require librt for some functions which might exist in other libraries in your OS. (sem_init() et al. are like this)
You might try to link without -lrt and see if it works.
I need to build R (http://www.r-project.org/) for Arch Linux ARM running on Raspberry Pi. I am having trouble running ./configure. I have built my own toolchain using crosstool-ng and it does work, I've compiled other applications with it just fine.
The issue appears to be that I cannot link the Fortran libraries to C code. Here is where configure fails:
checking for Fortran 77 libraries of gfortran... -L/home/njackson/bcm2708rpi-toolchain/lib -L/home/njackson/bcm2708rpi-toolchain/lib/gcc/arm-rpi-linux-gnueabi/4.7.3 -L/home/njackson/bcm2708rpi-toolchain/arm-rpi-linux-gnueabi/lib -L/usr/lib/gcc/x86_64-linux-gnu/4.6 -L/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.6/../../.. -lgfortran -lm /home/njackson/bcm2708rpi-toolchain/arm-rpi-linux-gnueabi/lib/libgfortran.a /home/njackson/bcm2708rpi-toolchain/lib/gcc/arm-rpi-linux-gnueabi/4.7.3/libgcc.a
checking for dummy main to link with Fortran 77 libraries... unknown
configure: error: in `/home/njackson/R-2.15.3':
configure: error: linking to Fortran libraries from C fails
See `config.log' for more details
It fails here.
I used the following configure command:
./configure --host=arm-linux-gnueabihf CC=/home/njackson/bcm2708rpi-toolchain/bin/arm-rpi-linux-gnueabi-gcc CXX=/home/njackson/bcm2708rpi-toolchain/bin/arm-rpi-linux-gnueabi-g++ FC=/home/njackson/bcm2708rpi-toolchain/bin/arm-rpi-linux-gnueabi-gfortran MAIN_LD=/home/njackson/bcm2708rpi-toolchain/bin/arm-rpi-linux-gnueabi-ld --with-readline=no
I'd appreciate help getting this compiled. Thanks.
I figured it out.
One should set F77=/path/to/gfortran instead of the FC variable.
I want to link an existing shared library (FlashRuntimeExtensions.so) to my C-code while compiling my own shared library. But whatever I try I always get the same error; that the file is in a wrong format. Does anybody have an idea on how to solve this?
Here is my compile command:
$ g++ -Wall ane.c FlashRuntimeExtensions.so -o aneObject
FlashRuntimeExtensions.so: could not read symbols: File in wrong format
collect2: ld gaf exit-status 1 terug
Your command line tries to generate x86 code and link it to ARM code using the native g++ available in your distribution.
This will not work. Use the Android NDK available here: http://developer.android.com/tools/sdk/ndk/index.html
The NDK includes a set of cross-toolchains (compilers, linkers, etc..) that can generate native ARM binaries on Linux, OS X, and Windows (with Cygwin) platforms.
In general .so will be linked using -l.
for example, pthread -lpthread we use.
gcc sample.c -o myoutput -lpthread
But as per #chill's statement, what you are doing in command is correct only.
I suggest you to refer the following link.
C++ Linker Error SDL Image - could not read symbols
It should be an architecture mismatch. I faced this problem once, I have solved it by building the libs in same target platform and it is obvious. If you are using linux or Unix like OS you can see that by file command and if you are using windows you can see that using Dependency Walker. You need to make sure that all the libs matches architecture.
i'm getting some troubles with QT it builds with option "-lrt"
i'm using mac os 10.6 with QT creator 1.2.1, heeeeeeelp !
this is the full build command :
g++ -headerpad_max_install_names -o
AMiningCoreTest main.o tokenizer.o
DictionnaryToolBox.o mysql.o btree.o
BTreeDataTable.o tcaccess.o
-L/Library/Frameworks -L/usr/lib/mysql -lmysqlclient -L/usr/local/lib/ -ltokyocabinet -lz -lbz2 -lrt -lpthread -lm -lc
and it ends with
ld: library not found for -lrt
collect2: ld returned 1 exit status
The linker cannot find librt which is probably the Posix real time extensions library. I don't think this is available on OSX. Googling gives this from Apple developer lists
Question from list
I'm trying to build a simulator developed in my university (on Linux)
and I get error by the linker that seems unable to find librt.a - in
the code is used for clock_gettime() and I would like to know if
there's a port of such library, or some other similar function that
allows me to compile even on Mac OS X.
Answer
librt.a is the System V name of the library containing the POSIX
Advanced Realtime [RT} Option functions. The specific function you are
asking about is part of the [TMR] option. If Mac OS X supported it, it
would be in libSystem.B,dylib, not librt.a. The function in question
is not supported by Mac OS X.
Your code should check to see whether optional to implement things
above and beyond the UNIX standard are implemented in the target OS,
and if they aren't, use a different interface.
Why does the program need librt?
I know that some platforms (Solaris comes to mind) require librt for some functions which might exist in other libraries in your OS. (sem_init() et al. are like this)
You might try to link without -lrt and see if it works.