Question

how do i change a file path which is in the form of `

c:\abc\efg\mmm.txt

to

c:\\abc\\mm.txt ?

and what can i do to change the

.txt
extension to, let’s say .doc?

`
EDIT:

These paths are just for illustration.

The actual paths are composed of drive letters and any number of subdirectories. And the file extensions can be of any format.

Answer 1

Your task is not quite clear. If you ONLY want to duplicate the backslashes AND it is pure C AND you don’t have wide chars (i.e. ASCII only), then you can do something along the lines of:

char* p = str;
char target[MAX_PATH + 1]; // or some other way to be sure it will hold the transformed string
char* t = target;

while (*p) {
  char ch = *p++;
  if (ch == '\\')
    *t++ = '\\';
  *t++ = ch;
}

*t = '\0';

This will duplicate the backslashes. In order to replace the extension, to keep things simple, you may want to detect the extension using int len = strlen(str); (may be as simple as checking last characters in the str). Once done, you can replace the while condition by while(p - str < len - 3) and then strcat(target, "doc");