# String parsing with `strparse` The functions take input via a pointer to a pointer, which allows the functions to advance the pointer on success which then by extension allows "chaining" of functions like this example that gets a word, a space and then a second word: ~~~c if(Curl_str_word(&line, &word1, MAX) || Curl_str_singlespace(&line) || Curl_str_word(&line, &word2, MAX)) fprintf(stderr, "ERROR\n"); ~~~ ## Strings The functions that return string information does so by populating a `struct Curl_str`: ~~~c struct Curl_str { char *str; size_t len; }; ~~~ ## `Curl_str_word` ~~~c int Curl_str_word(char **linep, struct Curl_str *out, const size_t max); ~~~ Get a sequence of bytes until the first space or the end of the string. Return non-zero on error. There is no way to include a space in the word, no sort of escaping. The word must be at least one byte, otherwise it is considered an error. `max` is the longest accepted word, or it returns error. On a successful return, `linep` is updated to point to the byte immediately following the parsed word. ## `Curl_str_until` ~~~c int Curl_str_until(char **linep, struct Curl_str *out, const size_t max, char delim); ~~~ Like `Curl_str_word` but instead of parsing to space, it parses to a given custom delimiter non-zero byte `delim`. `max` is the longest accepted word, or it returns error. The parsed word must be at least one byte, otherwise it is considered an error. ## `Curl_str_quotedword` ~~~c int Curl_str_quotedword(char **linep, struct Curl_str *out, const size_t max); ~~~ Get a "quoted" word. This means everything that is provided within a leading and an ending double character. No escaping possible. `max` is the longest accepted word, or it returns error. The parsed word must be at least one byte, otherwise it is considered an error. ## `Curl_str_single` ~~~c int Curl_str_single(char **linep, char byte); ~~~ Advance over a single character provided in `byte`. Return non-zero on error. ## `Curl_str_singlespace` ~~~c int Curl_str_singlespace(char **linep); ~~~ Advance over a single ASCII space. Return non-zero on error. ## `Curl_str_number` ~~~c int Curl_str_number(char **linep, size_t *nump, size_t max); ~~~ Get an unsigned decimal number. Leading zeroes are just swallowed. Return non-zero on error. ## `Curl_str_newline` ~~~c int Curl_str_newline(char **linep); ~~~ Check for a single CR or LF. Return non-zero on error */