CS256 - Principles of Structured Design Fall 2021

Displaying ./code/cs256su21code/jun30/writeFile.c

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/*
opening a file, and then printing it's contents to another file
called output.txt
*/
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[]){
        if(argc < 2){
                printf("Usage %s file\n", argv[0]);
                exit(1);
        }
        //declaring file pointers
        FILE *fp, *fd;
        fp = fopen(argv[1], "r");
        fd = fopen("output.txt", "w"); //here, we're writing the contents of the file we're reading
                                                                   //into output.txt
        int ch;
        //using fgetc to output each character to the file
        //fgetc takes 1 argument, the file we're reading
        //EOF means "end of file", it's a character at the end of every file
        //that marks the end of the file.
        while ( (ch = fgetc(fp)) != EOF ) {
                fputc(ch, fd);
        }
        //fputc outputs a single character to a file, it takes two 
        //arguments, the character and the file we're ouputting to
        //closing both files
        fclose(fp);
        fclose(fd);
        return 0;
}
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