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String copying and manipulation
Character Strings example from a Well House Consultants training course
More on Character Strings [link]

This example is described in the following article(s):
   • Strings in C - [link]

This example references the following resources:
http://efreedom.com/Question/1-2692993/Strcpy-Error-Warning

Source code: cx.c Module: C206
#include <stdio.h>
#include <string.h>

/* Strings are character arrays, null terminated. This example sets up one
as a read only (constant) and another as a variable, and manipuates the variable
one as a demonstration. */


// http://efreedom.com/Question/1-2692993/Strcpy-Error-Warning

main() {

                        // Read only string - not on heap or stack
                        // May give Segmentation or Bus Error on edit attempt
        char* gleeting = "Welcome to Melksham-on-Avon";

                        // Changeable one in application read/write space
                        // This example on stack; could malloc for heap
        char hi_henry[81];

        printf("Original: %s\n",gleeting);

/* A String is a null terminated character array */

// Print out from start - up to first thing that happens to be '0'

        hi_henry[0] = 65;
        hi_henry[1] = 'B';
        printf("Other: %s\n",hi_henry);

        hi_henry[2] = 0;
        printf("Other: %s\n",hi_henry);

// Can't copy gleeting to hi_henry with an assignement if I want to
// change the copy. It's then just 2 pointers to the same d*rned literal

// First crudish way:

        strcpy(hi_henry,gleeting);
        printf("Other: %s\n",hi_henry);

// Works - BUT considered unsafe due to possible overflow issues
// Try instead ...

        strncpy(hi_henry,gleeting,80); // Maximum 80 chars
        printf("Other: %s\n",hi_henry);

// String manipulation if you must (demo - not recommended as the
// way for productions most of the time!)

        strncpy(hi_henry,"A warm ",80);
        strncpy(hi_henry+7,gleeting,73);
        hi_henry[7] += 32;
        printf("Other: %s\n",hi_henry);

        }

/*

munchkin:cj grahamellis$ ./cx
Original: Welcome to Melksham-on-Avon
Other: AB?_?
Other: AB
Other: Welcome to Melksham-on-Avon
Other: Welcome to Melksham-on-Avon
Other: A warm welcome to Melksham-on-Avon
munchkin:cj grahamellis$

*/

Learn about this subject
This module and example are covered on the following public courses:
 * Learning to Program in C
 * Learning to program in C and C++
 * Programming in C
 * C and C++ Programming
 * Learning to program in C and C++
 * C and C++ Programming
Also available on on site courses for larger groups

Books covering this topic
Yes. We have over 700 books in our library. Books covering C and C++ are listed here and when you've selected a relevant book we'll link you on to Amazon to order.

Other Examples
This example comes from our "Character Strings" training module. You'll find a description of the topic and some other closely related examples on the "Character Strings" module index page.

Full description of the source code
You can learn more about this example on the training courses listed on this page, on which you'll be given a full set of training notes.

Many other training modules are available for download (for limited use) from our download centre under an Open Training Notes License.

Other resources
• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
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