C/stdio.h/freopen

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freopen: associates an existing stream with a different file

<source lang="cpp">

//Header file: #include <stdio.h> //Declaration: FILE *freopen(const char *fname, const char *mode, FILE *stream); //Return: returns a pointer to stream on success or a null pointer on failure. //Legal Values for the mode Parameter

//Mode Meaning //"r": Open text file for reading //"w": Create a text file for writing //"a": Append to text file //"rb": Open binary file for reading //"wb": Create binary file for writing //"ab": Append to a binary file //"r+": Open text file for read/write //"w+": Create text file for read/write //"a+": Open text file for read/write //"rb+" or "r+b": Open binary file for read/write //"wb+" or "w+b": Create binary file for read/write //"ab+" or "a+b": Open binary file for read/write


 #include <stdio.h>
 #include <stdlib.h>
 int main(void)
 {
   FILE *fp;
   printf("This will display on the screen.\n");
   if((fp=freopen("OUT", "w" ,stdout))==NULL) {
     printf("Cannot open file.\n");
     exit(1);
   }
   printf("This will be written to the file OUT.");
   fclose(fp);
   return 0;
 }
        
          
      </source>