Solved

Void-valued Function to extract substring from a string

Posted on 1997-04-05
1
253 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
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
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

Enroll in July's Course of the Month

July's Course of the Month is now available! Enroll to learn HTML5 and prepare for certification. It's free for Premium Members, Team Accounts, and Qualified Experts.

Question has a verified solution.

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

Often, when implementing a feature, you won't know how certain events should be handled at the point where they occur and you'd rather defer to the user of your function or class. For example, a XML parser will extract a tag from the source code, wh…
This article will show you some of the more useful Standard Template Library (STL) algorithms through the use of working examples.  You will learn about how these algorithms fit into the STL architecture, how they work with STL containers, and why t…
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 be introduced to the technique of using vectors in C++. The video will cover how to define a vector, store values in the vector and retrieve data from the values stored in the vector.

617 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