ch1-copyEOF

Chapter_1     Exercise_1-7

count     Exercise_1-8

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copyEOF.c         download

#include <stdio.h> // for getchar(), putchar(), printf(), fflush(),
// stdout, EOF
#include <unistd.h> // for sleep()

#define FALSE 0
#define TRUE 1

int main() // copy input to output, then EOF (EOF is not a char, is not part of input)
{ // when reading past the last char in input, getchar() returns EOF
int c;

while ((c = getchar()) != EOF)
{putchar(c);}

do
{
printf("%d", c); // EOF as int (-1)
fflush(stdout); // flush output buffer
sleep(1); // pause for 1 second
c = getchar(); // get EOF indefinitely
} while (TRUE); // for ever
}
/*
gcc copyEOF.c -o copyEOF
./copyEOF // input from keyboard
Hello! // Enter
Hello!
// Ctrl^D in Linux, Ctrl^Z+Enter in Windows (EOF)
-1-1-1-1-1-1-1-1-1-1^C
// end with Ctrl^C

./copyEOF < copyEOF.c // redirect input to file
// end with Ctrl^C

./copyEOF < copyEOF.c > copyEOF.txt
// wait for 10 seconds, then press Ctrl^C

rm copyEOF.txt // clean
*/

Notes:

printf("%d", c);
fflush(stdout); // flush output buffer
can be replaced with
printf("%d\n", c); // flush output buffer
and then each  -1  is printed on a separate line.

EOF  is defined as a macro (in stdio.h), with value  -1  (see Exercise_4-14):
#define EOF (-1) // on disk, /usr/include/stdio.h
As such, EOF  is not a character, whose ASCII values vary between 0 and 255 (see the ASCII_code).

The last character in a text file is usually  '\n'  (newline), with ASCII value 10  (0xA  in hexadecimal). You can verify this by opening a text file with a hexadecimal editor like bless or ghex. In Linux, you can install these programs with the following commands:
sudo apt-get install bless
sudo apt-get install ghex
Alternatively, you can use a text editor like Notepad++ and set it to View → Show Symbol → Show All Characters (LF is LineFeed, newline).

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