read_until
read_until — reads characters, constructing a string as it goes.
read_until (file, delimiters)
fileA file pointer to a previously opened file. This may be either a file in the file system, or a string opened for read and write.
delimitersA string of delimiter characters. "" indicates white space.
All characters in the file up to the first occurrence of any of
delimiter characters, or "Unexpected end of
file".
This function reads characters from the input file one at a time until it
reaches any of the delimiter characters, constructing
a string as it goes. Successive calls continue from the point of the
previous read_until. If the end of file is reached, the
function returns "Unexpected end of file".
An input file contains the following:
Lists can be
expressed as (a b c).Successive calls to read_until will produce:
Gamma>ft = open ("myreadlfile.dat","r");#<File:"myreadlfile.dat">Gamma>read_until(ft, "(");"Lists can be\nexpressed as "Gamma>read_until(ft,"x");"a b c)."Gamma>read_until(ft,"y");"Unexpected end of file"Gamma>
read, read_char, read_double, read_float, read_line, read_long, read_short