<html><head><meta http-equiv="content-type" content="text/html; charset=UTF-8"><style>body { line-height: 1.5; }blockquote { margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em; }body { font-size: 10.5pt; font-family: 微软雅黑; color: rgb(0, 0, 0); line-height: 1.5; }</style></head><body>
<div>think you very much.</div><div><br></div><div>as you said:</div><div><br></div><div><span></span>>POSIX and ISO-C tend to go together.</div><div><div>>With RTEMS, you can also use ISO-C with the "Classic API", which</div><div>>consists of interface functions accessible from C programs as</div><div>>described in the "C User Guide".</div></div><div><br></div><div>Does it mean that i can just use ISO-c? so ,i think I do not need care about posix API because i think i use the classic api is enough for me . is it right?</div><div><br></div><div><div>>Most new development and ports of existing software probably use POSIX</div><div>>anyway, except for the simplest applications. This configure option</div><div>>was provided historically as a way to avoid compiling the POSIX</div><div>>library into an application, but modern compilers are able to remove</div><div>>the unused code any way.</div></div><div><br></div>
<div>i think i understand what you said in this part . if i use the <span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"> </span><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;">--enable posix in the </span><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"> </span><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;">configure , but i do not use the posix api, then ,the compiler will not use the unused code .</span></div><div><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;"><br></span></div><div><span style="font-size: 10.5pt; line-height: 1.5; background-color: window;">thanks</span></div><hr style="width: 210px; height: 1px;" color="#b5c4df" size="1" align="left">
<div><span><div style="MARGIN: 10px; FONT-FAMILY: verdana; FONT-SIZE: 10pt"><div>bin.wang@qkmtech.com</div></div></span></div>
<blockquote style="margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em;"><div> </div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"><div style="PADDING-RIGHT: 8px; PADDING-LEFT: 8px; FONT-SIZE: 12px;FONT-FAMILY:tahoma;COLOR:#000000; BACKGROUND: #efefef; PADDING-BOTTOM: 8px; PADDING-TOP: 8px"><div><b>From:</b> <a href="mailto:gedare@rtems.org">Gedare Bloom</a></div><div><b>Date:</b> 2018-01-11 00:50</div><div><b>To:</b> <a href="mailto:bin.wang@qkmtech.com">bin.wang@qkmtech.com</a></div><div><b>CC:</b> <a href="mailto:chrisj@rtems.org">Chris Johns</a>; <a href="mailto:users@rtems.org">Users</a></div><div><b>Subject:</b> Re: Re: the difference between posix user and c user</div></div></div><div><div>On Thu, Dec 28, 2017 at 9:35 PM, bin.wang@qkmtech.com</div>
<div><bin.wang@qkmtech.com> wrote:</div>
<div>> is the posix api and the c api used together?</div>
<div>></div>
<div>POSIX and ISO-C tend to go together.</div>
<div> </div>
<div>With RTEMS, you can also use ISO-C with the "Classic API", which</div>
<div>consists of interface functions accessible from C programs as</div>
<div>described in the "C User Guide".</div>
<div> </div>
<div>> sorry . i am also confused about this two things . because i find that when</div>
<div>> i config the rtems kernel ,there is a option which is --enable posix.</div>
<div>></div>
<div>Most new development and ports of existing software probably use POSIX</div>
<div>anyway, except for the simplest applications. This configure option</div>
<div>was provided historically as a way to avoid compiling the POSIX</div>
<div>library into an application, but modern compilers are able to remove</div>
<div>the unused code any way.</div>
<div> </div>
<div>> ________________________________</div>
<div>> bin.wang@qkmtech.com</div>
<div>></div>
<div>></div>
<div>> From: bin.wang@qkmtech.com</div>
<div>> Date: 2017-12-29 09:25</div>
<div>> To: Chris Johns; Users</div>
<div>> Subject: Re: Re: the difference between posix user and c user</div>
<div>> i google the posix .now i know that posix is the abbreviation of "the</div>
<div>> Portable Operating System Interface" it is for software compatibility with</div>
<div>> variants of Unix and other operating systems</div>
<div>></div>
<div>> but you said, "POSIX and the Classic API are both C APIs."</div>
<div>> than i think the posix is packaged on the basis of the standard C, is it</div>
<div>> right ?</div>
<div>> the classic api is the standard c interface , is it right?</div>
<div>></div>
<div>> best wishes</div>
<div>></div>
<div>> ________________________________</div>
<div>> bin.wang@qkmtech.com</div>
<div>></div>
<div>></div>
<div>> From: Chris Johns</div>
<div>> Date: 2017-12-29 02:18</div>
<div>> To: users</div>
<div>> Subject: Re: the difference between posix user and c user</div>
<div>> On 29/12/17 12:00 am, bin.wang@qkmtech.com wrote:</div>
<div>>> hi everyone:</div>
<div>>></div>
<div>>> i am new to linux and rtems. i do not understand</div>
<div>>> what the difference between posix user and c user .</div>
<div>>></div>
<div>>> i am confused about these two concept. which condition i should choose</div>
<div>>> posix ?</div>
<div>>> which condition i should choose c ?</div>
<div>>></div>
<div>></div>
<div>> This is a good question and it is understandable why you do not understand</div>
<div>> the</div>
<div>> difference. The reason is specific to RTEMS and relates to it's history.</div>
<div>></div>
<div>> The original RTEMS was written in Ada and C and the C API is what we now</div>
<div>> call</div>
<div>> the Classic API. It's manual was called the C User Guide hence the name.</div>
<div>></div>
<div>> The Ada version of RTEMS was removed from the source tree and POSIX came a</div>
<div>> while</div>
<div>> later.</div>
<div>></div>
<div>> POSIX and the Classic API are both C APIs. The C User manual is now called</div>
<div>> the</div>
<div>> RTEMS Classic API Guide. See:</div>
<div>></div>
<div>> https://docs.rtems.org/</div>
<div>></div>
<div>> Chris</div>
<div>> _______________________________________________</div>
<div>> users mailing list</div>
<div>> users@rtems.org</div>
<div>> http://lists.rtems.org/mailman/listinfo/users</div>
<div>></div>
<div>></div>
<div>> _______________________________________________</div>
<div>> users mailing list</div>
<div>> users@rtems.org</div>
<div>> http://lists.rtems.org/mailman/listinfo/users</div>
<div> </div>
</div></blockquote>
</body></html>