error: usleep is not declared in this scope

[wangzheqie]

find that file,and add the following codes to it:

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

[Jackzhemliu]

This is helpful. Thanks.

[kuonangzhe]

This just solved my problem. Thanks a lot! @wangzheqie

[jtbon20]

@wangzheqie Why did it work before, but now trying to reinstall I need to add it to nearly all the files?

[wangzheqie]

so to me, I add it to all files needed without second thinking. And they all work.

[xuhangxx]

Thanks

[gerardsimons]

Thanks a lot. Why is this not already in the repo though?

[paulushcgcj]

Why do I need to add this?

I mean I can compile my code on Linux (CentOS 6) perfectly, but why do I need to add this includes when I'm using cygwin, ?

[riccitensor]

Works, but I had to add it to a bunch of files.

[kauevestena]

Was necessary to add in 11 files!
But thank you, worked
How does the developers solve this issue?

[Aceralon]

An easier way is to add #include <unistd.h> in System.h.

[CharithEkanayake]

@Aceralon Thanks your method just sorted issue really quickly

[CharithEkanayake]

@Aceralon
Were you able to run this on a camera feed?

[ujur007]

@wangzheqie thanks it solved my error after adding this headers in several files...
But why did I need to do this. ? What is the reason.?

[changshen]

I added this for my cygwin project in windows 10 for Code::Blocks
#ifdef _CYGWIN_
#include <sys/unistd.h>
#endif // CYGWIN

and the include path of cygwin c:/cygwin/usr/include should be in search path of compiler. Where
c:/cygwin is the install root of cygwin. And in settings of compilerof cygwin, add _CYGWIN_ in user defined files "#define". You can do this in project level or in global level.

[trehansiddharth]

I have replicated that ORB_SLAM2 won't compile on several systems without adding #include <unistd.h> to System.h, as @Aceralon suggested, even after commit #577. Can we incorporate this into the master branch? It seems like it is a simple change?

[Alex23013]

I had to add it to a bunch of files. But it works . thanks @wangzheqie

[K296]

I have replicated that ORB_SLAM2 won't compile on several systems without adding #include <unistd.h> to System.h, as @Aceralon suggested, even after commit #577. Can we incorporate this into the master branch? It seems like it is a simple change?

Why is this suggestion still not incorporated?

[Aceralon]

@Aceralon
Were you able to run this on a camera feed?

Yes

[stolpa4]

I have replicated that ORB_SLAM2 won't compile on several systems without adding #include <unistd.h> to System.h, as @Aceralon suggested, even after commit #577. Can we incorporate this into the master branch? It seems like it is a simple change?

Why is this suggestion still not incorporated?

Because the repo is dead. Author is lost somewhere

[Chatoyant19]

An easier way is to add #include <unistd.h> in System.h.

it works well! Thank u

[balisujohn]

An easier way is to add #include <unistd.h> in System.h.

This worked for me; thanks for your help!