NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part1/2466

Internet Message Format | 1996-08-05 | 1.8 KB

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From: Lawrence Kirby <[e-mail]>
Newsgroups: comp.lang.c
Subject: Re: Checking for a file => Does it exist (Help)
Date: Sun, 21 Jan 96 14:56:59 GMT
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References: <[e-mail]> <4dc6kq$[e-mail]> <[e-mail]> <[e-mail]> <4dr4d7$[e-mail]>
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In article <4dr4d7$[e-mail]>
           [e-mail] "Rajendra Singh" writes:

>Lawrence Kirby <[e-mail]> wrote:
>
>
>>The C language does not define a function called 'access'. POSIX does but
>>it is rather specialised and probably doesn't do what you want.
>
>That may be true, but EVERY C compiler that I have used has it:  AIX,
>HPUX, Watcom, Borland.

It doesn't matter how many platforms support it, if it does the wrong thing
on many of them. Have you read the man page for access on AIX or HPUX,
*carefully* ? While POSIX isn't part of C it is worth quoting the following
to indicate why you shouldn't use access in 'portable' code. From the access
description in  "POSIX Programmer's Guide" by Donald Lewine:

``access uses the real UID, not the effective UID. It is not a general utility
  for finding out "Can I do this?" before doing a call. It is used by SETUID
  programs to check their actions.''

If the standard C functions aren't up to your needs probably the most
portable solution to this is to use stat().

--
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Lawrence Kirby | [e-mail]
Wilts, England | [e-mail]
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