- NAME
GET_PIPE_FILESIZE
- PURPOSE
Determine the number of bytes in a unit opened as a pipe with SPAWN
- EXPLANATION
Reads into a buffer until the end of file is reached and then counts the
number of bytes read. Needed because the fstat.size field is not
automatically set for a unit opened as a pipe.
- CALLING SEQUENCE
GET_PIPE_FILESIZE,unit, nbytes_in_file, BUFFER =
- INPUTS
unit - IDL unit number of a previously opened file. For example,
an FPACK ( http://heasarc.gsfc.nasa.gov/fitsio/fpack/ ) compressed
FITS file could be opened as follows:
IDL> spawn,'funpack -S test.fits.fz', unit=unit
- OUTPUTS
nbytes_in_file - Unsigned long64 integer giving number of bytes in
the file.
- INPUT KEYWORD PARAMETERS
BUFFER Integer giving number of bytes in the buffer. Default =
1000000
- NOTES
Unite must be opened prior to calling GET_PIPE_FILESIZE, and the number
of bytes is counted from the current pointer position. The pointer is
left at the end of the file upon return.
- PROCEDURES USED
SETDEFAULTVALUE
- REVISION HISTORY
Written, W. Landsman Adnet Dec 2010