Question

I am using Linux GCC c99.

I am wondering what would be the best technique. To change a string. I am using strstr();

I have a filename called ‘file.vce’ and I want to change the extension to ‘file.wav’.

Is this the best method:

char file_name[80] = 'filename.vce'; char *new_file_name = NULL; new_file_name = strstr(file_name, 'vce'); strncpy(new_file_name, 'wav', 3); printf('new file name: %s\n', new_file_name); printf('file name: %s\n', file_name); 

Many thanks for any advice,

---

I have edited my answer using using your suggestions. Can you see anything else wrong?

/** Replace the file extension .vce with .wav */ void replace_file_extension(char *file_name) {     char *p_extension;      /** Find the extension .vce */     p_extension = strrchr(file_name, '.');     if(p_extension)     {         strcpy(++p_extension, 'wav');     }     else     {         /** Filename did not have the .vce extension */         /** Display debug information */     } }  int main(void) {     char filename[80] = 'filename.vce';      replace_file_extension(filename);      printf('filename: %s\n', filename);     return 0; } 

Answer 1

I would do this

char file_name[80] = 'filename.vce'; char *pExt;  pExt = strrchr(file_name, '.'); if( pExt )   strcpy(++pExt, 'wav'); else {  // hey no extension } printf('file name: %s\n', file_name); 

You NEED to do pointer manipulation in every c program. Of course you’d do some more checking for buffer over runs etc. or even use the path specific functions.