[FEEDBACK] Issue with fd_set, FD_ZERO, FD_SET, FD_SETSIZE : Cygwin

[Yeo Kai Wei]

On 7/2/2023 4:59 am, gs-cygwin.com@gluelogic.com wrote:
> On Tue, Feb 07, 2023 at 04:33:53AM +0800, Yeo Kai Wei wrote:
>> Hi All,
>>
>> Thanks for the help.
>>
>> I tried adding "#include <sys/select.h>".
>>
>> However, this is the error message that was returned to me.
>>
>> $ gcc -o selectStdIn selectStdIn.c
>> selectStdIn.c:9:10: fatal error: sys/select.h: No such file or directory
>>   #include <sys/select.h>
>>
>> Thank you.
>>
>> On 7/2/2023 4:30 am,gs-cygwin.com@gluelogic.com  wrote:
>>> On Tue, Feb 07, 2023 at 04:25:22AM +0800, Yeo Kai Wei via Cygwin wrote:
>>>> Hi,
>>>>
>>>> I would like to report an issue with Cygwin 3.4.2 on Windows.
>>>>
>>>> It doesn't seem to be able to work with  fd_set, FD_ZERO, FD_SET, FD_SETSIZE
>>>> macros.
>>>>
>>>> The code is in italics. The filename was selectStdIn.c. The terminal command
>>>> used was "gcc -o selectStdIn selectStdIn.c"
>>>>
>>>> Thank you.
>>>>
>>>> /
>>>> /
>>>>
>>>> /CODE
>>>> /
>>>>
>>>> /#include <stdio.h>//
>>>> //#include <stdlib.h>//
>>>> //#include <sys/time.h>//
>>>> //#include <unistd.h>//
>>>> / /
>>>> //void main()//
>>>> //{//
>>>> //    fd_set fds; //set of file descriptors//
>>>> / /
>>>> //    struct timeval tv;//
>>>> / /
>>>> //    int flag;//
>>>> / /
>>>> //    char byte;//
>>>> / /
>>>> //    FD_ZERO(&fds);//
>>>> / /
>>>> //    FD_SET(0, &fds);//
>>>> / /
>>>> //    tv.tv_sec = 5;//
>>>> / /
>>>> //    tv.tv_usec = 0;//
>>>> / /
>>>> //    flag = select(FD_SETSIZE, //
>>>> //            &fds,//
>>>> //            NULL,//
>>>> //            NULL,//
>>>> //            &tv);//
>>>> / /
>>>> //    if(-1 == flag)//
>>>> //        perror("select error");//
>>>> //    else if(flag)//
>>>> //    {//
>>>> //        read(0,&byte,1);//
>>>> / /
>>>> //        puts("data read");//
>>>> //    }//
>>>> / /
>>>> //    if(flag)//
>>>> //        printf("The byte value is %c\n", byte);//
>>>> ////
>>>> //}/
>>>>
>>>>
>>>> TERMINAL COMMANDS
>>>>
>>>> $ gcc -o selectStdIn selectStdIn.c
>>>> selectStdIn.c: In function 'main':
>>>> selectStdIn.c:8:2: error: unknown type name 'fd_set'; did you mean 'fpos_t'?
>>>>     fd_set fds; //set of file descriptors
>>>>     ^~~~~~
>>>>     fpos_t
>>>> selectStdIn.c:16:2: warning: implicit declaration of function 'FD_ZERO'
>>>> [-Wimpli
>>>> cit-function-declaration]
>>>>     FD_ZERO(&fds);
>>>>     ^~~~~~~
>>>> selectStdIn.c:18:2: warning: implicit declaration of function 'FD_SET'
>>>> [-Wimplic
>>>> it-function-declaration]
>>>>     FD_SET(0, &fds);
>>>>     ^~~~~~
>>>> selectStdIn.c:24:9: warning: implicit declaration of function 'select'; did
>>>> you
>>>> mean 'sleep'? [-Wimplicit-function-declaration]
>>>>     flag = select(FD_SETSIZE,
>>>>            ^~~~~~
>>>>            sleep
>>>> selectStdIn.c:24:16: error: 'FD_SETSIZE' undeclared (first use in this
>>>> function)
>>>>     flag = select(FD_SETSIZE,
>>>>                   ^~~~~~~~~~
>>>> selectStdIn.c:24:16: note: each undeclared identifier is reported only once
>>>> for
>>>> each function it appears in
>>> $ man select
>>>
>>> #include <sys/select.h>
> Please post at bottom of messages on this mailing list.
>
> You need to install the cygwin-devel package to get <sys/select.h>
>
> Cheers, Glenn

Hi All,

Thanks for the help.

Is this the correct link?

https://www.cygwin.com/packages/summary/cygwin-devel.html

I assume I should download the following

3.4.5-1 	310 KiB 	2023-01-19 19:25 	[list of files 
<https://www.cygwin.com/packages/x86_64/cygwin-devel/cygwin-devel-3.4.5-1>] 
	stable


Thank you very much.


Kind Regards,

YEO Kai Wei