error: function returns address of local variable

by

The local variables have a lifetime which extends only inside the block in which it is defined. The moment the control goes outside the block in which the local variable is defined, the storage for the variable is no more allocated (not guaranteed). Therefore, using the memory address of the variable outside the lifetime area of the variable will be undefined behaviour.

On the other hand you can do the following.

 char *str_to_ret = malloc (sizeof (char) * required_size);
  .
  .
  .
 return str_to_ret;

And use the str_to_ret instead. And when returning str_to_ret, the address allocated by malloc will be returned. The memory allocated by malloc is allocated from the heap, which has a lifetime which spans the entire execution of the program. Therefore, you can access the memory location from any block and any time while the program is running.

Also note that it is a good practice that after you have done with the allocated memory block, free it to save from memory leaks. Once you free the memory, you can’t access that block again.

More Related Contents:

  1. GCC – modify where execution continues after function return [closed]
  2. How can I correctly assign a new string value?
  3. Why should you use strncpy instead of strcpy?
  4. Returning string from C function
  5. Return address of local variable in C
  6. Returning local data from functions in C and C++ via pointer
  7. C – why is strcpy() necessary
  8. strcpy() return value
  9. Best practice for compute the function return value
  10. strcpy vs strdup
  11. Return char[]/string from a function [duplicate]
  12. What is the difference between exit and return?
  13. What is the difference between using _exit() & exit() in a conventional Linux fork-exec?
  14. Segmentation Fault in strcpy()
  15. Does C have a string type? [closed]
  16. Why does this intentionally incorrect use of strcpy not fail horribly?
  17. realloc(): invalid next size when reallocating to make space for strcat on char * [duplicate]
  18. How to return a 2D array from a function in C?
  19. What exactly is -fno-builtin doing here?
  20. How to know the do while loop in C programming [closed]
  21. Fast way to tokenize a string in c
  22. Connecting n commands with pipes in a shell?
  23. Modifying C string constants? [duplicate]
  24. Recursive declaration of function pointer in C
  25. Type to use to represent a byte in ANSI (C89/90) C?
  26. Confusion regarding modification of const variable using pointers
  27. Calling a script from a setuid root C program – script does not run as root
  28. Using getchar() in a while loop
  29. Is it possible to print out only a certain section of a C-string, without making a separate substring?
  30. flock(): removing locked file without race condition?

Leave a Comment