Solved

Void-valued Function to extract substring from a string

Posted on 1997-04-05
1
246 Views
Last Modified: 2010-04-10
I need help in writing a a void-valued function to extract a substring from an existing string.

For Example:
     char   sub[80];
     ...
     substr ('Converting to C', 7, 4, &sub);

would store the string 'ting' into the variable called 'sub'. The function should store a NUL character at the end of the extracted string.
0
Comment
Question by:cyrax
1 Comment
 

Accepted Solution

by:
linpage earned 50 total points
ID: 1162578
the following will do it.  However most 'c' programmers would probably make your example substr('Converting to C', 6, 4, &sub);   because of the 0 offset convention (change the line to while ( *src && start-- > 0) for this).  This snippet tests for the
src running out, but not the destination buffer.  You might want
to include a length for dest to be on the safe side.

void substr(const char* src, int start, int len, char ** dest)
{
  while ( *src && --start > 0)
      src++;
 
  while ( *src && len > 0)
  {
    **dest = *src;
    *dest++;
    src++;
    len--;
  }
  **dest = 0x00;
}
0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

IntroductionThis article is the second in a three part article series on the Visual Studio 2008 Debugger.  It provides tips in setting and using breakpoints. If not familiar with this debugger, you can find a basic introduction in the EE article loc…
Introduction This article is a continuation of the C/C++ Visual Studio Express debugger series. Part 1 provided a quick start guide in using the debugger. Part 2 focused on additional topics in breakpoints. As your assignments become a little more …
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.

756 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question