Solution for Exercise 22-2

ex2202

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

int main()
{
    FILE *fh;
    int ch;

    /* open the file */
    fh=fopen("hello.txt","r");
    /* check for errors */
    if(fh==NULL)
    {
        puts("Can't open that file!");
        exit(1);
    }
    /* loop until the end-of-file */
    while( !feof(fh) )
    {
        /* read one character */
        ch=fgetc(fh);
        /* end of file? */
        if( ch==EOF )
            break;
        /* output character */
        putchar(ch);
    }
    /* close the file */
    fclose(fh);
    return(0);
}

Output

Look what I made!

Notes

* This code assumes the file hello.txt exists in the same directory where the program is run. The output assumes the file's content as well.

* If you don't use the if test in the while loop (at Line 23), the EOF "character" is output, which adds an extra blank character to the output on most systems.

* Another way to write the while loop is like this:

while( (ch=getc(fh))!=EOF ) putchar(ch);

The expression ch=getch(fh) must be enclosed in parentheses to prevent it from being evaluated directly. Inside the parentheses, its return value is compared as an int with the EOF constant.

Exercise ex2203 →