mex c compile using arc4random_uniform gets undefined reference to `arc4random_uniform' collect2.exe: error: ld returned 1 exit status

I am trying to install SPIKY on Matlab 2019b which has as part of the SPIKY install the mex script:

mex -Dchar16_t=uint16_T SPIKE_order_surro_MEX.c

The program

SPIKE_order_surro_MEX.c

contains the following:

while (sc<num_swaps) {
        brk=0;
        coin=arc4random_uniform(num_coins)+1;    // get random integer

The compile generates the following error:

Building with 'MinGW64 Compiler (C)'

.

Error using mex
C:\Users\RobLe\AppData\Local\Temp\mex_57607468677249_25364\SPIKE_order_surro_MEX.obj:SPIKE_order_surro_MEX.c:(.text+0x1d0): undefined reference to
`arc4random_uniform'
collect2.exe: error: ld returned 1 exit status

Error in SPIKY_compile_MEX (line 27)
    mex -Dchar16_t=uint16_T SPIKE_order_surro_MEX.c

Any idea how I fix this ?

Thanks

[Jan]

What is SPIKY? Can you provide a link to this software package? Did you contact the authors already?

[ROBERT LENZIE]

Jan, Thanks for getting back. SPIKY is code for analysis of neuronal spike trains. The download page is here http://wwwold.fi.isc.cnr.it/users/thomas.kreuz/Source-Code/SPIKY.html

I contacted them and they suggested changing

// coin=arc4random_uniform(num_coins)+1; // gets random integer between 1 and num_coins

to

coin=arc4random_uniform % num_coins; // gets random integer between 0 and num_coins-1
coin = coin +1; // increment by 1  

which produced a similar error. For some reason the compiler on my machine is not able to find

arc4random_uniform

They also suggested using arc4random instead of arc4random_uniform which again prodces a similar error.

[James Tursa]

Can you find the functions arc4random or arc4random_uniform anywhere in your source code?

[ROBERT LENZIE]

e.g

coin=arc4random % num_coins; // gets random integer between 0 and num_coins-1

coin = coin +1; // increment by 1

[ROBERT LENZIE]

this source code line is in the module SPIKE_order_surro_MEX.c

[ROBERT LENZIE]

the package writer got back to me and suggested the following fix. The problem is I am using Windows 10 and not unix/linux :

Please find the solution below.

First, they need to install the bsd library:

Open the terminal Ctrl+Alt+T

(optionally run the sudo apt-get update)

sudo apt-get install libbsd-dev

Second, they need to add it to our code (SPIKE_order_surro_MEX.c): (they could use MATLAB editor)

#include <bsd/stdlib.h>

I have added it after #include <string.h>

Finally, they need to pass the -lbsd to the mex compiler

mex -lbsd SPIKE_order_surro_MEX.c

I have installed Ubuntu 18.04 this morning on my hyper-v virtual machine. I downloaded SPIKY, installed GCC. And with those 3 steps it works.

Let me know if they still have problems,

Cheers,

n.