I/O

exists/1

succeeds if a file exists

open/3

open a file or a string as a stream

close/1

close a stream

write/2

write some term to a stream

nl/1

write a new-line to a stream

writeln/2

write a term to a stream, followed by a new-line

writeq/2

write a term in canoncial form, so that if can be read back

read/2

read a term from a stream

read_string/4

read a string from a stream

concat_string/2

build a string from a list of components

phrase/3

call DCG analyzer

read_exdr/2

read a term from a file in EXDR format

write_exdr/2

write a term to a file in EXDR format

flush/1

flush an output stream