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Re: Parsing based on 1st and 2nd spaces in a string

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On 6/4/2017 2:24 PM, Barry Schwarz wrote:
> On Sun, 4 Jun 2017 07:48:31 -0400, DFS <nospam@dfs.com> wrote:
> 
>> I have text input in only two formats:
>>
>> Value line goes like this...
>> # Value line goes like this...
>>
>> Value is of varying lengths, but never > 20.
>> # is always numeric, and never exceeds 9.
>>
>> Goal is to capture Value and '# Value'
>>
>> I'm currently using a combination of strchr() and isdigit(), which works
>> fine, but I'm wondering if there's a better way to handle the lines that
>> begin with '# Value'.
>>
>> current code is:
>> -----------------------------------------------------------
>> if (!isdigit(line[0]))
>>   {	// no leading digit so parse on 1st space
>> 	strncpy(thevalue, line, strchr(line, ' ') - line);
>>   }
>> else
>>   index=(strchr(line,' ')-line)+1;  //get position of 1st space
>>   for(i=index;i<30;i++)		   //find and parse on 2nd space	
>>   {
>> 	if(line[i] == ' ')
>> 	{	strncpy(thevalue, line, i);
>> 		break;
>> 	}
>>   }
>> -----------------------------------------------------------
>>
>> Ideas or suggestions?
>>
>> Thanks!
> 
> For the second case, since # never exceeds 9, is it not guaranteed
> that line[1] == ' ' and index will always be 2?  

Good spot: yes, if the first character is a digit, index will always be 2.

What was I thinking?  Jeez.


> Furthermore, your
> code assumes line[2] != ' '.  If that is the case, i should never be
> greater that 22.

Yeah, I just put in 30 for some wiggle room.


> If the above is all true, you can simplify the else to
>     strncpy(thevalue, line, strcspn(line+2," ")+2);

Works great.

This is why I posted.  Another set of eyes.  Chopped 5 unnecessary lines 
from the code.


> Presumably you have some other code that insures that thevalue is
> properly terminated with a '\0'.

Each time before thevalue is re/assigned:
memset(thevalue,'\0',sizeof(thevalue));


Thanks Barry.

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Thread

Parsing based on 1st and 2nd spaces in a string DFS <nospam@dfs.com> - 2017-06-04 07:48 -0400
  Re: Parsing based on 1st and 2nd spaces in a string "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-06-04 15:53 +0200
    Re: Parsing based on 1st and 2nd spaces in a string DFS <nospam@dfs.com> - 2017-06-04 10:29 -0400
      Re: Parsing based on 1st and 2nd spaces in a string "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-06-04 21:52 +0200
        Re: Parsing based on 1st and 2nd spaces in a string DFS <nospam@dfs.com> - 2017-06-04 16:43 -0400
      Re: Parsing based on 1st and 2nd spaces in a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-04 22:39 +0100
        Re: Parsing based on 1st and 2nd spaces in a string Keith Thompson <kst-u@mib.org> - 2017-06-04 19:40 -0700
        Re: Parsing based on 1st and 2nd spaces in a string DFS <nospam@dfs.com> - 2017-06-05 00:08 -0400
          Re: Parsing based on 1st and 2nd spaces in a string raltbos@xs4all.nl (Richard Bos) - 2017-06-05 08:52 +0000
            Re: Parsing based on 1st and 2nd spaces in a string Robert Wessel <robertwessel2@yahoo.com> - 2017-06-05 23:51 -0500
          Re: Parsing based on 1st and 2nd spaces in a string Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-05 12:37 +0100
          Re: Parsing based on 1st and 2nd spaces in a string "James R. Kuyper" <jameskuyper@verizon.net> - 2017-06-05 12:53 -0400
  Re: Parsing based on 1st and 2nd spaces in a string Barry Schwarz <schwarzb@dqel.com> - 2017-06-04 11:24 -0700
    Re: Parsing based on 1st and 2nd spaces in a string DFS <nospam@dfs.com> - 2017-06-04 16:43 -0400

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