File input/output: Difference between revisions

=={{header|BCPL}}==

<lang bcpl>GET "libhdr"

LET start() BE $(

// Attempt to open the named files.

LET source = findinput("input.txt")

LET destination = findoutput("output.txt")

TEST source = 0 THEN

writes("Unable to open input.txt*N")

ELSE TEST destination = 0 THEN

writes("Unable to open output.txt*N")

ELSE $(

// The current character, initially unknown.

LET ch = ?

// Make the open files the current input and output streams.

selectinput(source)

selectoutput(destination)

// Copy the input to the output character by character until

// endstreamch is returned to indicate input is exhausted.

ch := rdch()

UNTIL ch = endstreamch DO $(

wrch(ch)

ch := rdch()

$)

// Close the currently selected streams.

endread()

endwrite()

$)

$)</lang>