isOpen -- whether a file or database is open

Synopsis

• Usage:

  isOpen f

• Inputs:
  • f, a file or a database
• Outputs:
  • a Boolean value, whether f is an open file or open database

Description

An open file is either an input file, an output file, an input output file, or a listener.

i1 : f = "test-file" << "hi there"

o1 = test-file

o1 : File

i2 : isOpen f

o2 = true

i3 : close f

o3 = test-file

o3 : File

i4 : isOpen f

o4 = false

i5 : get "test-file"

o5 = hi there

i6 : removeFile "test-file"

See also

• openIn -- open an input file
• openInOut -- open an input output file
• openListener -- open a port for listening
• close -- close a file
• get -- get the contents of a file
• removeFile -- remove a file