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Date: Thu, 11 Jan 1996 22:14:59 -0700
From: Nate Williams <nate@sri.MT.net>
Message-Id: <199601120514.WAA23403@rocky.sri.MT.net>
To: Josh MacDonald <jmacd@CS.Berkeley.EDU>
Cc: freebsd-hackers@freebsd.org
Subject: Re: mktemp() sucks, why not fix it?
In-Reply-To: <199601120419.UAA07014@paris.CS.Berkeley.EDU>
References: <199601120419.UAA07014@paris.CS.Berkeley.EDU>
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> I don't like how:
> 
> main()
> {
>     char buf1[] = "/tmp/foo.XXXXXX", buf2[] = "/tmp/foo.XXXXXX";
>     mktemp(buf1);
>     symlink("/tmp/existsbutnotdirectory/foo", buf1);
>     if(mktemp(buf2) == NULL)
>         perror("mktemp() failed");
>     printf("buf1 = %s\nbuf2 = %s\n", buf1, buf2);
> }
> 
> the second call to mktemp() fails, and they both end up
> with the same value.

I'll be the first call to mktemp fails as well, unless you happen to be
compiling with -fwritable-strings.

You have to pass in data to mktemp which can be modified, which neither
of the above strings can be.

Try this instead:
int
main()
{
    char buf1[255], buf2[255];

    strcpy(buf1, "/tmp/foo.XXXXXX");
    strcpy(buf2, "/tmp/foo.XXXXXX");
    if ( mktemp(buf1) == NULL )
        perror("mktemp() failed");
    symlink("/tmp/existsbutnotdirectory/foo", buf1);
    if(mktemp(buf2) == NULL)
        perror("mktemp() failed");
    printf("buf1 = %s\nbuf2 = %s\n", buf1, buf2);
}


Nate