The delimited-I/O module can be accessed with:
(use-modules (ice-9 rdelim))
It can be used to read or write lines of text, or read text delimited by
a specified set of characters. It’s similar to the
module from guile-scsh, but does not use multiple values or character
sets and has an extra procedure
Return a line of text from port if specified, otherwise from the
value returned by
(current-input-port). Under Unix, a line of text
is terminated by the first end-of-line character or by end-of-file.
If handle-delim is specified, it should be one of the following symbols:
Discard the terminating delimiter. This is the default, but it will be impossible to tell whether the read terminated with a delimiter or end-of-file.
Append the terminating delimiter (if any) to the returned string.
Push the terminating delimiter (if any) back on to the port.
Return a pair containing the string read from the port and the terminating delimiter or end-of-file object.
read-char, this procedure can throw to
Read a line of text into the supplied string buf and return the
number of characters added to buf. If buf is filled, then
#f is returned.
Read from port if
specified, otherwise from the value returned by
Read text until one of the characters in the string delims is found
or end-of-file is reached. Read from port if supplied, otherwise
from the value returned by
handle-delim takes the same values as described for
Read text into the supplied string buf.
If a delimiter was found, return the number of characters written,
except if handle-delim is
split, in which case the return
value is a pair, as noted above.
As a special case, if port was already at end-of-stream, the EOF
object is returned. Also, if no characters were written because the
buffer was full,
#f is returned.
It’s something of a wacky interface, to be honest.
Display obj and a newline character to port. If
port is not specified,
used. This function is equivalent to:
(display obj [port]) (newline [port])
In the past, Guile did not have a procedure that would just read out all
of the characters from a port. As a workaround, many people just called
read-delimited with no delimiters, knowing that would produce the
behavior they wanted. This prompted Guile developers to add some
routines that would read all characters from a port. So it is that
(ice-9 rdelim) is also the home for procedures that can reading
Read all of the characters out of port and return them as a string. If the count is present, treat it as a limit to the number of characters to read.
By default, read from the current input port, with no size limit on the result. This procedure always returns a string, even if no characters were read.
Fill buf with characters read from port, defaulting to the current input port. Return the number of characters read.
If start or end are specified, store data only into the substring of str bounded by start and end (which default to the beginning and end of the string, respectively).
Some of the aforementioned I/O functions rely on the following C primitives. These will mainly be of interest to people hacking Guile internals.
Read characters from port into str until one of the
characters in the delims string is encountered. If
gobble is true, discard the delimiter character;
otherwise, leave it in the input stream for the next read. If
port is not specified, use the value of
(current-input-port). If start or end are
specified, store data only into the substring of str
bounded by start and end (which default to the
beginning and end of the string, respectively).
Return a pair consisting of the delimiter that terminated the
string and the number of characters read. If reading stopped
at the end of file, the delimiter returned is the
eof-object; if the string was filled without encountering
a delimiter, this value is
Read a newline-terminated line from port, allocating storage as
necessary. The newline terminator (if any) is removed from the string,
and a pair consisting of the line and its delimiter is returned. The
delimiter may be either a newline or the eof-object; if
%read-line is called at the end of file, it returns the pair
(#<eof> . #<eof>).