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![Jeff King](/assets/img/avatar_default.png)
The usual pattern for an argv array is to initialize it, push in some strings, and then clear it when done. Very occasionally, though, we must do other exotic things with the memory, like freeing the list but keeping the strings. Let's provide a detach function so that callers can make use of our API to build up the array, and then take ownership of it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
66 lines
2.2 KiB
Plaintext
66 lines
2.2 KiB
Plaintext
argv-array API
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==============
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The argv-array API allows one to dynamically build and store
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NULL-terminated lists. An argv-array maintains the invariant that the
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`argv` member always points to a non-NULL array, and that the array is
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always NULL-terminated at the element pointed to by `argv[argc]`. This
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makes the result suitable for passing to functions expecting to receive
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argv from main(), or the link:api-run-command.html[run-command API].
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The link:api-string-list.html[string-list API] is similar, but cannot be
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used for these purposes; instead of storing a straight string pointer,
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it contains an item structure with a `util` field that is not compatible
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with the traditional argv interface.
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Each `argv_array` manages its own memory. Any strings pushed into the
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array are duplicated, and all memory is freed by argv_array_clear().
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Data Structures
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---------------
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`struct argv_array`::
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A single array. This should be initialized by assignment from
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`ARGV_ARRAY_INIT`, or by calling `argv_array_init`. The `argv`
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member contains the actual array; the `argc` member contains the
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number of elements in the array, not including the terminating
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NULL.
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Functions
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---------
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`argv_array_init`::
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Initialize an array. This is no different than assigning from
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`ARGV_ARRAY_INIT`.
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`argv_array_push`::
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Push a copy of a string onto the end of the array.
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`argv_array_pushl`::
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Push a list of strings onto the end of the array. The arguments
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should be a list of `const char *` strings, terminated by a NULL
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argument.
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`argv_array_pushf`::
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Format a string and push it onto the end of the array. This is a
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convenience wrapper combining `strbuf_addf` and `argv_array_push`.
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`argv_array_pushv`::
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Push a null-terminated array of strings onto the end of the array.
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`argv_array_pop`::
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Remove the final element from the array. If there are no
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elements in the array, do nothing.
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`argv_array_clear`::
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Free all memory associated with the array and return it to the
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initial, empty state.
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`argv_array_detach`::
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Disconnect the `argv` member from the `argv_array` struct and
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return it. The caller is responsible for freeing the memory used
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by the array, and by the strings it references. After detaching,
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the `argv_array` is in a reinitialized state and can be pushed
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into again.
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