All Questions
3,145
questions
311
votes
4
answers
168k
views
What are the differences between .so and .dylib on macOS?
.dylib is the dynamic library extension on macOS, but it's never been clear to me when I can't / shouldn't use a traditional unix .so shared object.
Some of the questions I have:
At a conceptual ...
- 3,469
238
votes
16
answers
143k
views
Finding current executable's path without /proc/self/exe
It seems to me that Linux has it easy with /proc/self/exe. But I'd like to know if there is a convenient way to find the current application's directory in C/C++ with cross-platform interfaces. I've ...
- 2,601
192
votes
16
answers
140k
views
Can't compile C program on a Mac after upgrade to Mojave
I have used the gcc command on the terminal to compile C programs but all of a sudden, after an update to my Mac's OS (to macOS 10.14 Mojave, and XCode 10.0), I started receiving the message:
test.c:...
- 3,748
178
votes
19
answers
647k
views
How can I compile and run C/C++ code in a Unix console or Mac terminal?
How can I compile/run C or C++ code in a Unix console or a Mac terminal?
- 11.1k
123
votes
4
answers
9k
views
Why does rand() repeat numbers far more often on Linux than Mac?
I was implementing a hashmap in C as part of a project I'm working on and using random inserts to test it. I noticed that rand() on Linux seems to repeat numbers far more often than on Mac. RAND_MAX ...
- 1,353
122
votes
10
answers
390k
views
How can I run a C program on Mac OS X using Terminal?
I am new to C. Here is my "Hello, World!" program.
#include <stdio.h>
int main(void)
{
printf("Hello, World!\n");
return 0;
}
After I try to run it using Terminal it ...
- 1,855
108
votes
8
answers
303k
views
104
votes
16
answers
77k
views
Can't compile a C program on a Mac after upgrading to Catalina 10.15
There's a previous question Can't compile C program on a Mac after upgrade to Mojave, and the answers to that have covered most of the variations on what goes wrong.
Now — as of Monday 2019-10-07 — ...
- 746k
87
votes
10
answers
100k
views
How to Compile for OS X in Linux or Windows?
I would like to port my C/C++ apps to OS X.
I don't have a Mac, but I have Linux and Windows. Is there any tool for this?
- 46.5k
77
votes
5
answers
80k
views
readelf-like tool for Mac OS X? [closed]
Is there a tool for reading Mac OS X binaries that would print information about relocation tables and symbol offsets similar to this readelf output?
readelf -r app
Relocation section '.rel.dyn' at ...
- 92.9k
73
votes
13
answers
101k
views
clock_gettime alternative in Mac OS X
When compiling a program I wrote on Mac OS X after installing the necessary libraries through MacPorts, I get this error:
In function 'nanotime':
error: 'CLOCK_REALTIME' undeclared (first use in this ...
- 80.9k
68
votes
5
answers
109k
views
List of all users and groups
I'm trying to get a list of all users and all groups on Mac OS X 10.5+. How can I do this?
For example, the list of all users on my machine should return:
_amavisd, _appowner, _appserver, _ard, ...
- 243k
66
votes
3
answers
38k
views
sem_init on OS X
I am working on some code which uses the pthread and semaphore libraries. The sem_init function works fine on my Ubuntu machine, but on OS X the sem_init function has absolutely no effect. Is there ...
- 20.2k
63
votes
6
answers
43k
views
Which macro to wrap Mac OS X specific code in C/C++
While reading various C and C++ sources, I have encountered two macros __APPLE__ and __OSX__. I found plenty of use of __OSX__ in various codes, especially those originating from *BSD systems.
...
- 38.1k
63
votes
1
answer
3k
views
Weak symbol aliases on OS X similar to those on Linux, or a closest equivalent?
What I do
When writing shared libraries for Linux, I tend to pay attention to relocations, symbol visibility, GOT/PLT etc.
When applicable, I am trying to avoid calling PLT stubs when functions from ...
user405725
60
votes
6
answers
156k
views
Typing "gcc --version" outputs clang version instead on mac
I am using OS 10.9 on mac machine. I want to know the version of gcc I am using. So I tried gcc --version on terminal and it results :
$ gcc --version
Configured with: --prefix=/Applications/Xcode5-...
- 2,746
60
votes
2
answers
15k
views
Why Swift is 100 times slower than C in this image processing test? [duplicate]
Like many other developers I have been very excited about the new Swift language from Apple. Apple has claimed its speed is faster than Objective C and can be used to write operating system. And from ...
- 14.1k
51
votes
2
answers
32k
views
Why are sem_init(), sem_getvalue(), sem_destroy() deprecated on Mac OS X — and what replaces them?
When I compile a program using the POSIX sem_init() function, I get a compilation warning (error because I normally use -Werror) that the function has been deprecated when I compile on Mac OS X 10.10....
- 746k
48
votes
8
answers
83k
views
How do you do non-blocking console I/O on Linux in C?
How do you do nonblocking console IO on Linux/OS X in C?
- 2,159
43
votes
4
answers
95k
views
How to set up libusb on Mac OS X?
I'd like to try to make a user-space device driver using libusb on Mac, but I'm confused where to start. In the SDK installer (which I got from http://www.ellert.se/twain-sane) it said something about ...
- 2,387
41
votes
3
answers
35k
views
Creating static Mac OS X C build
How can i create a static build of a .c file on Mac OS X ? When i try:
gcc -o test Main.c -static
I get:
ld: library not found for -lcrt0.o
collect2: ld returned 1 exit status
- 3,047
39
votes
6
answers
25k
views
How to convert ASCII character to CGKeyCode?
I need a function that, given a character, returns the CGKeyCode associated with the position of that character on the current keyboard layout. E.g., given "b", it should return kVK_ANSI_B if using U....
- 11.9k
37
votes
6
answers
32k
views
Nano syntax highlighting in Mac OS X 10.7 (Lion)?
How to enable syntax highlighting for nano in Mac OS X 10.7 (Lion)?
According to what I found so far on Google is that it has got to do with /.nanorc file. I have no idea how to get it or make it?
...
- 5,475
36
votes
9
answers
12k
views
editline/history.h and editline/readline.h not found/working on macOS when trying to compile with developer tools installed already
I am working on this tutorial on building your own LISP (http://www.buildyourownlisp.com/chapter4_interactive_prompt) and for some reason when I try to compile I get this:
REPL.c:4:10: fatal error: '...
- 1,070
36
votes
7
answers
106k
views
Good C IDE for Mac? [closed]
I've just started a job where I'm programming in C on a Mac, which is my first experience using a Mac for development. For now I'm using Xcode as my editor, then using make/gcc/svn at the command line ...
- 9,910
36
votes
8
answers
26k
views
`"<program>" would like to access files in your Documents folder` message with VS Code and macOS Catalina
I'm using Visual Studio Code with the C/C++ official extension from Microsoft to write C programs, running under macOS Catalina 10.15.3. The project folder lies in a path within the Documents folder ...
- 2,684
35
votes
5
answers
52k
views
Where is the standard C library on Mac OS X?
I am trying to find the standard C library on Mac OS X. I've tried paths like: "/usr/lib/libc.a" or "/usr/lib/libm.a" , but there aren’t such files on the system. Where can I find ...
- 603
35
votes
3
answers
13k
views
Retrieve names of running processes
First off, I know that similar questions have been asked, but the answers provided haven't been very helpful so far (they all recommend one of the following options).
I have a user application that ...
- 243k
32
votes
10
answers
55k
views
Where is my "stdio.h" in Mac?
I know that Mac OS X is a Unix-based system. And I heard that C standard library such as stdio.h, is located in /usr/local/include or /usr/include. But there is not any kind of library in this ...
- 5,590
31
votes
2
answers
10k
views
Cross compiling GCC with newlib for ARM: how to specify GCC options like -march?
I've compiled GCC along with newlib on Mac OS X for ARM targets. However, libc.a was compiled with -fshort-enums, and I don't want that because when I compile stuff for ARM, I use -fno-short-enums. ...
- 2,105
30
votes
7
answers
27k
views
Creating a windowed application in pure C on MacOS
I'm creating an application in pure C on Mac OSX. What I want is to create a window in which my app will be displayed.
Preferably I want it to be pure C solution, but if I have to use Objective-C ...
- 495
30
votes
2
answers
45k
views
How to install gtk on OSX for use with g++/gcc compiler
I already asked this question at apple.stackexchange.com, but I was told it was the wrong place for this question - so I will ask it here, as I was suggested to do.
At my university we got the task ...
- 6,552
29
votes
7
answers
31k
views
Programmatically retrieving the absolute path of an OS X command-line app
On Linux, an application can easily get its absolute path by querying /proc/self/exe. On FreeBSD, it's more involved, since you have to build up a sysctl call:
int mib[4];
mib[0] = CTL_KERN;
mib[1] =...
- 28.1k
29
votes
5
answers
24k
views
Unknown ending signal when using debugger gdb
I have installed GDB on Mac OS X and to test that it works I have used this following C program.
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[]) {
int *...
- 1,055
29
votes
4
answers
20k
views
GCC left shift overflow
The following little program is very awkward using GCC version 4.2.1 (Apple Inc. build 5664) on a Mac.
#include <stdio.h>
int main(){
int x = 1 << 32;
int y = 32;
...
- 481
27
votes
6
answers
22k
views
How can a file contain null bytes?
How is it possible that files can contain null bytes in operating systems written in a language with null-terminating strings (namely, C)?
For example, if I run this shell code:
$ printf "Hello\00, ...
- 887
27
votes
3
answers
73k
views
What is `S_ISREG()`, and what does it do?
I came across the macro S_ISREG() in a C program that retrieves file attributes. Unfortunately, there isn't any basic information about this macro online. There are some more advanced discussions on ...
- 2,316
27
votes
2
answers
8k
views
Detect in C if outputting to a terminal
I'm writing a C program for OS X and Linux, and I want to tweak the output based on whether or not it's going to a terminal. I know we've covered how to do this in a shell script, e.g. here:
...
- 24.2k
27
votes
1
answer
11k
views
Cannot get lldb to read file input through redirect
I'm using lldb as a standalone debugger in OSX. I'm trying to debug a C executable, using a text file as input, by way of a redirect. The lldb documentation specifies the following command for ...
- 1,149
27
votes
5
answers
15k
views
Is a Linux executable "compatible" with OS X?
If you compile a program in say, C, on a Linux based platform, then port it to use the MacOS libraries, will it work?
Is the core machine-code that comes from a compiler compatible on both Mac and ...
- 1,879
26
votes
6
answers
9k
views
How come a 32 bit kernel can run a 64 bit binary?
On my OS X box, the kernel is a 32-bit binary and yet it can run a 64-bit binary.
How does this work?
cristi:~ diciu$ file ./a.out
./a.out: Mach-O 64-bit executable x86_64
cristi:~ diciu$ file /...
- 29.3k
26
votes
10
answers
8k
views
Can gdb make a function pointer point to another location?
I'll explain:
Let's say I'm interested in replacing the rand() function used by a certain application.
So I attach gdb to this process and make it load my custom shared library (which has a ...
- 92.9k
26
votes
3
answers
12k
views
Build Apple Silicon binary on Intel machine
How can I compile a C project on macOS 11 (Intel) to work on Silicon?
My current build script is as simple as:
./configure
make
sudo make install
I've tried using the --host and --target flags with ...
- 1,100
25
votes
5
answers
42k
views
endian.h not found on mac osx
I meet some trouble when I compile some C code on my mac which give me this error :
fatal error: 'endian.h'
file not found
I did some google search about this problem.It seems like mac os x ...
- 429
25
votes
8
answers
22k
views
Reading Other Process' Memory in OS X?
I've been trying to understand how to read the memory of other processes on Mac OS X, but I'm not having much luck. I've seen many examples online using ptrace with PEEKDATA and such, however it doesn'...
- 1
25
votes
3
answers
17k
views
Default libraries linked in by gcc?
Let's say I have a very simple C file (called foo.c):
int main()
{
printf("foo");
return 0;
}
Now I call gcc:
gcc foo.c
When I call gcc (with no options, as in the above example), what ...
- 1,561
24
votes
1
answer
20k
views
Do I really need libgcc?
I've been using GCC 4.6.2 on Mac OS X 10.6. I use the -static-libgcc option when I compile, otherwise my binaries look for libgcc on the system and I'm not sure anything over GCC 4.2 is supported on ...
- 2,105
23
votes
8
answers
32k
views
How to guarantee 64-bit writes are atomic?
When can 64-bit writes be guaranteed to be atomic, when programming in C on an Intel x86-based platform (in particular, an Intel-based Mac running MacOSX 10.4 using the Intel compiler)? For example:
...
23
votes
6
answers
16k
views
What C preprocessor conditional should I use for OS X specific code?
What C preprocessor conditional should I use for OS X specific code? I need to include a specific library if I am compiling for OS X or a different header if I am compiling for Linux.
I know there is ...
- 1,076
22
votes
3
answers
16k
views
How use Instruments and display the console in Command Lines applications [duplicate]
I'm using Xcode on OSX to develop command line C applications. I would also like to use Instruments to profile and find memory leaks.
However, I couldn't find a way to display the console when ...
- 8,611