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Full Discussion: Pure C function pointer on printing vowels twice
Top Forums Programming Pure C function pointer on printing vowels twice Post 302997639 by Corona688 on Wednesday 17th of May 2017 03:49:42 PM
Old 05-17-2017
Quote:
Originally Posted by yifangt
The return value is EOF or a single vowel, which is the first part bugging me.

Does that mean in if (putchar(c) == EOF || putchar(c) == EOF) , function putchar(c) gets actually executed twice?
Yes. To evaluate the expression, it has to call the function.

Quote:
I thought this line is just a condition
Slapping an if() around it doesn't change it. Would you expect this to print the values?

Code:
#include <stdio.h>

int main(void) {
    printf("a") && printf("b");
}

Treat anything inside an if() the exact same way.

Quote:
Let me put my question in another way:
Is there another layer
No.

For C, the answer to this question is always "no".

With very specific exceptions - like atexit() - C will never call a function without being asked.
 

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pure-mrtginfo

pure-mrtginfo(8)                                                     Pure-FTPd                                                    pure-mrtginfo(8)

NAME

       pure-mrtginfo - provide an MRTG-graphable user count for ftpd

SYNOPSIS

       pure-mrtginfo [server port]

DESCRIPTION

       Pure-Mrtginfo counts the number of clients currently connected to ftpd(8) and output the format in a format graphable by MRTG.

OPTIONS

       server port : defaults to 21.

FILES

       /proc/net/tcp
              is used to count the connectiont to port 21.

       /proc/sys/kernel/hostname
              is used to get the fully qualified hostname.

       /proc/uptime
              is used to get the uptime.

MRTG

       MRTG  is  a  really  nice package for graphing router traffic.  Mrtg can also graph other information is available via SNMP or by running a
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       connected to his FTP servers.  See
       http://oss.oetiker.ch/mrtg/
       for more information about MRTG.

BUGS

       This program only works on GNU/Linux systems yet.

HOME PAGE

       http://www.pureftpd.org/

AUTHOR AND LICENSE

       Written  by  Arnt Gulbrandsen <agulbra@troll.no> and copyright 1995-2002 Troll Tech AS, Waldemar Thranes gate 98B, N-0175 Oslo, Norway, fax
       +47 22806380.

       Pure-FTPd (C)opyleft 2001-2011 by Frank DENIS <j at pureftpd dot org> and the Pure-FTPd team.

       Use, modification and distribution is allowed without limitation, warranty, or liability of any kind.

SEE ALSO

       ftp(1), pure-ftpd(8) pure-ftpwho(8) pure-mrtginfo(8) pure-uploadscript(8) pure-statsdecode(8) pure-pw(8) pure-quotacheck(8) pure-authd(8)

       RFC 959, RFC 2228, RFC 2389 and RFC 2428.

Pure-FTPd Team                                                        1.0.36                                                      pure-mrtginfo(8)
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