<div dir="ltr">Yeah, for the optstring the colon means you need to specify something with that individual switch, which doesn't apply to this project since the file/folder operands apply to the program itself, not the individual switches.<div><br></div><div>If you check out the manpage for getopt(3), it has examples of how the colon works.</div></div><br><div class="gmail_quote"><div dir="ltr">On Fri, Oct 13, 2017 at 1:14 PM mseaton <<a href="mailto:mseaton@stevens.edu">mseaton@stevens.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Jason,<br>
<br>
Yeah, I am referring to the opstring of getopt(3) as well the operands.<br>
For example: (ls -a) and (ls -a DIRNAME) should both work. getopt(3)<br>
says that you must place a ":" after an option if it should return an<br>
argument. By doing this, ls -a won't work.<br>
I guess you are saying I should not place a ":" after any of the command<br>
options. In which case I won't have to worry about optarg which was what<br>
I used to determine if an argument was entered or not.<br>
<br>
Thanks.<br>
Marlon<br>
On 10/13/2017 11:15 AM, Jason Ajmo wrote:<br>
> I'm not sure if you're referring to the optstring for getopt(3) or the<br>
> program operands, but neither are required. You should specify your<br>
> optstring in a way that won't error if no options are supplied.<br>
><br>
> getopt(3) doesn't process the operands; just the command line<br>
> switches. That's why, after getopt(3) is done, you need to decrement<br>
> argc, and increment argv to get the proper starting point of the<br>
> operands.<br>
><br>
> On Fri, Oct 13, 2017 at 11:11 AM mseaton <<a href="mailto:mseaton@stevens.edu" target="_blank">mseaton@stevens.edu</a>> wrote:<br>
><br>
>> Hello,<br>
>><br>
>> I understand setting opterr to zero means that getopt will not<br>
>> report an<br>
>> error if no argument is entered, but our options must be able to<br>
>> work in<br>
>> both cases, however it still does not allow the program to continue<br>
>> if<br>
>> no argument is entered.<br>
>><br>
>> Is there something I am missing?<br>
>> Thanks<br>
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><br>
> --<br>
><br>
> Jason Ajmo<br>
> Stevens Institute of Technology<br>
> B.S. Cybersecurity '17<br>
> M.S. Computer Science '18<br>
> 0x56FA3123<br>
><br>
> Links:<br>
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</blockquote></div><div dir="ltr">-- <br></div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Jason Ajmo</div><div>Stevens Institute of Technology</div><div>B.S. Cybersecurity '17</div><div>M.S. Computer Science '18</div><div>0x56FA3123</div></div></div>