C/stdio.h/freopen
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>