[Info-vax] SCP2 and large files

[Arne Vajhøj]

On 8/12/2020 8:48 AM, John Reagan wrote:
> On Wednesday, August 12, 2020 at 2:47:52 AM UTC-4, Jeremy Begg wrote:
>> a. Can the CRTL stat() routine be told to guess the file size from the
>> RMS file header (ALQ perhaps)?  I thought there might be a DECC$ feature
>> logical to do this, but I can't find it.
> 
> You mean "st_size" in the stat buffer, yes?  We do use RMS (if the file is on network device, we'll fall back to a $QIOW/IO$_ACCESS and dig through the FAT but I doubt you are doing that path)
> 
>        1   51613     if (fhc->xab$l_ebk != 0)            /* Calculate file size in bytes */
>        1   51614         stat_buf->st_size = (off64_t)(fhc->xab$l_ebk - 1) * RMS_BLOCKSIZE + fhc->xab$w_ffb;
>        1   51615     else
>        1   51616         stat_buf->st_size = (off64_t)fhc->xab$l_hbk * RMS_BLOCKSIZE + fhc->xab$w_ffb;

One should just remember that the relationship between "size of file on
disk" and "bytes that will be read from file" can be rather complex on
VMS.

Arne