FileTools[Text]

 read a float from a file

Parameters

 file - file descriptor or filename

Description

 • The ReadFloat(file) command attempts to read a float from file.  The ReadFloat command skips whitespace until an integer or non-whitespace character is found.  If there is a valid float, it is read from file and returned.  If the characters do not form a valid float, then NULL is returned.
 • If no float is found, the file position is reset to its value before the call to ReadFloat was made.
 • To determine if the end of the file has been reached, use AtEndOfFile.
 • If file is the name of a file that has not been opened, Maple attempts to open the file before reading the float.
 • An error is raised if file is not a valid descriptor or if it is the name of a file that has not been opened.

Examples

 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{Open}\right]\left("testfile"\right)$
 ${0}$ (1)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{WriteString}\right]\left("testfile","2.73 to 3.14"\right)$
 ${12}$ (2)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{Close}\right]\left("testfile"\right):$
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{ReadFloat}\right]\left("testfile"\right)$
 ${2.73}$ (3)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{ReadFloat}\right]\left("testfile"\right)$
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{ReadString}\right]\left("testfile"\right)$
 ${"to"}$ (4)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{ReadFloat}\right]\left("testfile"\right)$
 ${3.14}$ (5)
 > $\mathrm{FileTools}\left[\mathrm{Text}\right]\left[\mathrm{ReadFloat}\right]\left("testfile"\right)$