Position - Maple Help

FileTools

 Position
 set or return the current position within a file

 Calling Sequence Position(file, pos)

Parameters

 file - filename or file descriptor pos - (optional) integer offset into the file or infinity

Description

 • The Position(file) command returns the current position within the specified file. This is the position to which the next write takes place, or from which the next read takes place.
 • The Position(file, pos) command sets the current position within the specified file and returns that new position.
 • A specified position of infinity sets the current position to the end of the file.
 • If file does not refer to an open file, an error is raised.
 • To determine a position suitable for passing to Position in a text file, call Position. Only values returned by Position(file) are guaranteed to be meaningful when used in Position(file, pos). Counting characters while reading and/or writing is not reliable, because newline characters are translated from/to local conventions, which may use more than a single character. However, Position(file, infinity) is always valid.

Examples

 > $\mathrm{testfile}≔\mathrm{FileTools}\left[\mathrm{TemporaryFile}\right]\left("test"\right)$
 ${\mathrm{testfile}}{≔}{"/tmp/test"}$ (1)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{WriteFile}\right]\left(\mathrm{testfile},"This is a test."\right)$
 ${15}$ (2)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{Open}\right]\left(\mathrm{testfile}\right)$
 > $\mathrm{FileTools}\left[\mathrm{Position}\right]\left(\mathrm{testfile},\mathrm{\infty }\right)$
 ${15}$ (3)