Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: printf() problem
Keywords: C printf
Message-ID: <10130@smoke.BRL.MIL>
Date: 26 Apr 89 15:33:12 GMT
References: <11657@hodge.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 9

In article <11657@hodge.UUCP> jdm@hodge.UUCP (jdm) writes:
>        printf("%x %x %x %x\n", getc(fp), getc(fp), getc(fp), getc(fp));

The order of evaluation of function arguments in C is unspecified.
Some implementations evaluate the last argument first, others don't.
Since getc(fp) has a side effect (it advances an external stream),
the order of evaluation matters in this example, therefore the code
is not portable.  Your solution works, as would a succession of four
printf() invocations each printing one getc(fp) result.