#ifndef ARGV_ARRAY_H

#define ARGV_ARRAY_H

/**

 * The argv-array API allows one to dynamically build and store

 * NULL-terminated lists.  An argv-array maintains the invariant that the

 * `argv` member always points to a non-NULL array, and that the array is

 * always NULL-terminated at the element pointed to by `argv[argc]`. This

 * makes the result suitable for passing to functions expecting to receive

 * argv from main().

 *

 * The string-list API (documented in string-list.h) is similar, but cannot be

 * used for these purposes; instead of storing a straight string pointer,

 * it contains an item structure with a `util` field that is not compatible

 * with the traditional argv interface.

 *

 * Each `argv_array` manages its own memory. Any strings pushed into the

 * array are duplicated, and all memory is freed by argv_array_clear().

 */

extern const char *empty_argv[];

/**

 * A single array. This should be initialized by assignment from

 * `ARGV_ARRAY_INIT`, or by calling `argv_array_init`. The `argv`

 * member contains the actual array; the `argc` member contains the

 * number of elements in the array, not including the terminating

 * NULL.

 */

struct argv_array {

	const char **argv;

	int argc;

	int alloc;

};

#define ARGV_ARRAY_INIT { empty_argv, 0, 0 }

/**

 * Initialize an array. This is no different than assigning from

 * `ARGV_ARRAY_INIT`.

 */

void argv_array_init(struct argv_array *);

/* Push a copy of a string onto the end of the array. */

const char *argv_array_push(struct argv_array *, const char *);

/**

 * Format a string and push it onto the end of the array. This is a

 * convenience wrapper combining `strbuf_addf` and `argv_array_push`.

 */

__attribute__((format (printf,2,3)))

const char *argv_array_pushf(struct argv_array *, const char *fmt, ...);

/**

 * Push a list of strings onto the end of the array. The arguments

 * should be a list of `const char *` strings, terminated by a NULL

 * argument.

 */

LAST_ARG_MUST_BE_NULL

void argv_array_pushl(struct argv_array *, ...);

/* Push a null-terminated array of strings onto the end of the array. */

void argv_array_pushv(struct argv_array *, const char **);

/**

 * Remove the final element from the array. If there are no

 * elements in the array, do nothing.

 */

void argv_array_pop(struct argv_array *);

/* Splits by whitespace; does not handle quoted arguments! */

void argv_array_split(struct argv_array *, const char *);

/**

 * Free all memory associated with the array and return it to the

 * initial, empty state.

 */

void argv_array_clear(struct argv_array *);

/**

 * Disconnect the `argv` member from the `argv_array` struct and

 * return it. The caller is responsible for freeing the memory used

 * by the array, and by the strings it references. After detaching,

 * the `argv_array` is in a reinitialized state and can be pushed

 * into again.

 */

const char **argv_array_detach(struct argv_array *);

#endif /* ARGV_ARRAY_H */