gd_strtok man page
gd_strtok — tokenise a string using the GetData parser
char *gd_strtok(DIRFILE *dirfile, const char *string);
The gd_strtok() function parses a string into a series of tokens according to the rules of the Dirfile metadata syntax (see dirfile-format(5)). The first time gd_strtok() is called, the string to be parsed should be passed in string. The first token will be returned. In subsequent calls to parse the same string, string should be NULL (as with strtok(3)). Each time gd_strtok() is called like this, the next token is returned.
Operation of the Dirfile tokeniser varies between Dirfile Standards Versions. The Standards Version used is the current Version of the loaded DIRFILE dirfile. Use gd_dirfile_standards(3) to retrieve or change this value. Changing the Standards Version of dirfile while parsing a string will affect the parsing of subsequent tokens, but does not affect tokens already returned. A copy of the string is cached in the dirfile object. Calling gd_strtok() with different dirfiles will parse different strings.
Upon successful completion, gd_strtok() returns a copy of the first token, if string is non-NULL, or else a subsequent token from the previously specified string, if string is NULL. Every non-NULL pointer returned by gd_strtok() points to a new buffer allocated on the heap. By default, strdup(3) is used the allocate the buffers, but an alternate memory manager may be used by calling gd_alloc_funcs(3) before calling this function. The caller is responsible for deallocating all these buffers.
If no more tokens are available, or if an error occurred, NULL is returned. If an error has occurred, it will also set the dirfile error a non-zero error value. Possible error values are:
A memory allocation error occurred.
There was no string to parse (i.e. string was NULL, but no previous call specified a string to parse).
The supplied dirfile was invalid.
A syntax error was found in the string.
The dirfile error may be retrieved by calling gd_error(3). A descriptive error string for the last error encountered can be obtained from a call to gd_error_string(3).
The gd_strtok() function appeared in GetData-0.8.0.
gd_dirfile_standards(3), gd_open(3), dirfile-format(5)