sdrstring3

Usage

    #include "sdr.h"
    Object sdr_string_create (Sdr sdr, char *from);
    Object sdr_string_dup    (Sdr sdr, Object from);
    int    sdr_string_length (Sdr sdr, Object string);
    int    sdr_string_read   (Sdr sdr, char *into, Object string);

Overview

SDR strings are used to record strings of up to 255 ASCII characters in the heap space of an SDR. Unlike standard C strings, which are terminated by a zero byte, SDR strings record the length of the string as part of the string object.

To store strings longer than 255 characters, use sdr_malloc() and sdr_write() instead of these functions.

Object sdr_string_create(Sdr sdr, char *from)

Creates a "self-delimited string" in the heap of the indicated SDR, allocating the required space and copying the indicated content. from must be a standard C string for which strlen() must not exceed 255; if it does, or if insufficient SDR space is available, 0 is returned. Otherwise the address of the newly created SDR string object is returned. To destroy, just use sdr_free().

Object sdr_string_dup(Sdr sdr, Object from)

Creates a duplicate of the SDR string whose address is from, allocating the required space and copying the original string's content. If insufficient SDR space is available, 0 is returned. Otherwise the address of the newly created copy of the original SDR string object is returned. To destroy, use sdr_free().

int sdr_string_length(Sdr sdr, Object string)

Returns the length of the indicated self-delimited string (as would be returned by strlen()), or -1 on any error.

int sdr_string_read(Sdr sdr, char *into, Object string)

Retrieves the content of the indicated self-delimited string into memory as a standard C string (NULL terminated). Length of into should normally be SDRSTRING_BUFSZ (i.e., 256) to allow for the largest possible SDR string (255 characters) plus the terminating NULL. Returns length of string (as would be returned by strlen()), or -1 on any error.