Displays a file in reverse order - C File

C examples for File:File Read

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Description

Displays a file in reverse order

Demo Code

#include <stdio.h>
#include <stdlib.h>

#define CNTL_Z '\032'   /* eof marker in DOS text files */
#define SLEN 81/*w w  w  . ja  va2s.  c o  m*/

int main(void){
    char file[SLEN];
    char ch;
    FILE *fp;
    long count, last;
    
    puts("Enter the name of the file to be processed:");
    scanf("%80s", file);
    if ((fp = fopen(file,"rb")) == NULL)
    {                               /* read-only mode   */
        printf("reverse can't open %s\n", file);
        exit(EXIT_FAILURE);
    }
    
    fseek(fp, 0L, SEEK_END);        /* go to end of file */
    last = ftell(fp);
    for (count = 1L; count <= last; count++)
    {
        fseek(fp, -count, SEEK_END); /* go backward      */
        ch = getc(fp);
    if (ch != CNTL_Z && ch != '\r')  /* MS-DOS files */
            putchar(ch);
    }
    putchar('\n');
    fclose(fp);
    
    return 0;
}

Result


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