Sometimes we build a set of similar command lines, differing
only in the final arguments (e.g., "fetch --multiple"). To
use argv_array for this, you have to either push the same
set of elements repeatedly, or break the abstraction by
manually manipulating the array's internal members.
Instead, let's provide a sanctioned "pop" function to remove
elements from the end.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It can be convenient to push many strings in a single line
(e.g., if you are initializing an array with defaults). This
patch provides a convenience wrapper to allow this.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An empty argv-array is initialized to point to a static
empty NULL-terminated array. The original implementation
separates the actual storage of the NULL-terminator from the
pointer to the list. This makes the exposed type a "const
char **", which nicely matches the type stored by the
argv-array.
However, this indirection means that one cannot use
empty_argv to initialize a static variable, since it is
not a constant.
Instead, we can expose empty_argv directly, as an array of
pointers. The only place we use it is in the ARGV_ARRAY_INIT
initializer, and it decays to a pointer appropriately there.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The submodule code recently grew generic code to build a
dynamic argv array. Many other parts of the code can reuse
this, too, so let's make it generically available.
There are two enhancements not found in the original code:
1. We now handle the NULL-termination invariant properly,
even when no strings have been pushed (before, you
could have an empty, NULL argv). This was not a problem
for the submodule code, which always pushed at least
one argument, but was not sufficiently safe for
generic code.
2. There is a formatted variant of the "push" function.
This is a convenience function which was not needed by
the submodule code, but will make it easier to port
other users to the new code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
