Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #76705

Re: EOF issue

Show all headers | View raw

Richard Heathfield <rjh@cpax.org.uk> writes:
[...]
> To get you started, here is an echo program:
>
> #include <stdio.h>
>
> int main(void)
> {
>    int c = 0;
>    while((c = getchar()) != EOF)
>    {
>      putchar(c);
>    }
>    return 0;
> }
>
> This will copy the program's input to its output, and it has the 
> advantage of being very, very simple (and correct).

And it's a simple version of "cat", not "echo".

> Use it (compile and run it) to figure out how to signal an end-of-file 
> condition from standard input (as outlined above).

On Unix-like systems (including Mac OSX), end-of-file while reading from
a keyboard is signalled by typing Ctrl-D once at the beginning of a line
(i.e., either as the first input or immediately after typing <Enter>)
*or* by typing Ctrl-D twice other than at the beginning of a line.  The
latter is uncommon; you usually want complete lines of input.

You can also provide input in batch mode.  For example, you can provide
your program with a single line of input by typing:

    echo hello | ./your_program

or multiple lines like this:

    ( echo "line one" ; echo "line two" ) | ./your_program

or

    printf "line one\nline two\n" | ./your_program

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

EOF issue Alla _ <modelling.data@gmail.com> - 2015-11-18 01:03 -0800
  Re: EOF issue Ian Collins <ian-news@hotmail.com> - 2015-11-18 22:55 +1300
    Re: EOF issue Alla _ <modelling.data@gmail.com> - 2015-11-18 02:54 -0800
      Re: EOF issue "Osmium" <r124c4u102@comcast.net> - 2015-11-18 06:48 -0600
        Re: EOF issue Lőrinczy Zsigmond <nospam@for.me> - 2015-11-18 16:35 +0100
          Re: EOF issue "Osmium" <r124c4u102@comcast.net> - 2015-11-18 12:58 -0600
      Re: EOF issue Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-18 16:31 +0000
  Re: EOF issue Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-18 11:00 +0000
    Re: EOF issue Alla _ <modelling.data@gmail.com> - 2015-11-18 07:31 -0800
      Re: EOF issue Richard Heathfield <rjh@cpax.org.uk> - 2015-11-18 17:34 +0000
        Re: EOF issue Keith Thompson <kst-u@mib.org> - 2015-11-20 17:57 -0800
      Re: EOF issue Barry Schwarz <schwarzb@dqel.com> - 2015-11-18 11:44 -0800
        Re: EOF issue alla.rashitova@gmail.com - 2015-11-19 00:47 -0800
          Re: EOF issue Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-19 05:56 -0800
            Re: EOF issue Richard Heathfield <rjh@cpax.org.uk> - 2015-11-19 16:22 +0000
      Re: EOF issue Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-18 21:09 +0000

csiph-web