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URI Parser (uri)

A URI string parsing module that splits a URI into its constituent components.

URI Format​

scheme:[//[user[:pass]@]host[:port]][/path][?query][#fragment]

Example:

https://admin:secret@example.com:8080/api/data?key=value#section
  │       │     │       │           │    │        │          │
scheme   user   pass   host       port  path    query    fragment

Data Structure​

struct uri_t {
    char * scheme;    /* Scheme name, e.g. "http", "ftp" */
    char * user;      /* Username */
    char * pass;      /* Password */
    char * host;      /* Hostname or IP (supports IPv6 [::1] format) */
    int port;         /* Port number, 0 if unspecified */
    char * path;      /* Path */
    char * query;     /* Query string (without '?') */
    char * fragment;  /* Fragment identifier (without '#') */
};

All string fields are independently allocated copies; absent parts are NULL. port is 0 when unspecified.

API​

struct uri_t * uri_alloc(const char * s);

Parse a URI string and return a split uri_t structure. Returns NULL on parse failure. Allocates independent memory for each field internally.

void uri_free(struct uri_t * uri);

Free the uri_t and all its string fields.

Parsing Rules​

  • scheme — Must start with a letter, may contain letters, digits, +, -, ., terminated by :
  • authority — The part starting with //, containing user info, host, and port
  • user:pass — The part before @, with : separating username and password (password may be omitted)
  • host — Supports IPv6 addresses (enclosed in brackets, e.g., [::1])
  • port — Numeric only, range 0~65535
  • path — The part after authority, before ? or #
  • query — The part after ?, before #
  • fragment — The part after #
  • Control characters are not allowed

Usage Examples​

Parsing a Full URI​

struct uri_t * uri = uri_alloc("https://admin:pass@example.com:8080/api?q=1#top");
/* uri->scheme   = "https"  */
/* uri->user     = "admin"  */
/* uri->pass     = "pass"   */
/* uri->host     = "example.com" */
/* uri->port     = 8080     */
/* uri->path     = "/api"   */
/* uri->query    = "q=1"    */
/* uri->fragment = "top"    */
uri_free(uri);

Parsing a Partial URI​

struct uri_t * uri = uri_alloc("mailto:test@example.com");
/* uri->scheme = "mailto" */
/* uri->path   = "test@example.com" */
/* Remaining fields are NULL or 0 */
uri_free(uri);

Parsing an IPv6 Address​

struct uri_t * uri = uri_alloc("http://[::1]:3000/path");
/* uri->host = "[::1]" */
/* uri->port = 3000 */
uri_free(uri);