# `Git.Commands.CatFile`
[🔗](https://github.com/joshrotenberg/git_wrapper_ex/blob/main/lib/git/commands/cat_file.ex#L1)

Implements the `Git.Command` behaviour for `git cat-file`.

Provides content or type/size information for repository objects.
Supports pretty-printing object contents, querying object type or size,
and checking whether an object exists.

Interactive and batch modes are intentionally not supported because they
require stdin interaction which cannot be driven programmatically.

# `t`

```elixir
@type t() :: %Git.Commands.CatFile{
  exists: boolean(),
  filters: boolean(),
  object: String.t() | nil,
  print: boolean(),
  size: boolean(),
  textconv: boolean(),
  type: boolean()
}
```

# `args`

```elixir
@spec args(t()) :: [String.t()]
```

Returns the argument list for `git cat-file`.

Builds the argument list from the struct fields. Exactly one of the mode
flags (`:type`, `:size`, `:print`, `:exists`) should be set, or none for
the default pretty-print behaviour.

## Examples

    iex> Git.Commands.CatFile.args(%Git.Commands.CatFile{object: "HEAD", type: true})
    ["cat-file", "-t", "HEAD"]

    iex> Git.Commands.CatFile.args(%Git.Commands.CatFile{object: "HEAD", size: true})
    ["cat-file", "-s", "HEAD"]

    iex> Git.Commands.CatFile.args(%Git.Commands.CatFile{object: "HEAD", print: true})
    ["cat-file", "-p", "HEAD"]

    iex> Git.Commands.CatFile.args(%Git.Commands.CatFile{object: "HEAD", exists: true})
    ["cat-file", "-e", "HEAD"]

    iex> Git.Commands.CatFile.args(%Git.Commands.CatFile{object: "HEAD", textconv: true})
    ["cat-file", "--textconv", "HEAD"]

    iex> Git.Commands.CatFile.args(%Git.Commands.CatFile{object: "HEAD", filters: true})
    ["cat-file", "--filters", "HEAD"]

# `parse_output`

```elixir
@spec parse_output(String.t(), non_neg_integer()) ::
  {:ok, atom()}
  | {:ok, integer()}
  | {:ok, String.t()}
  | {:ok, boolean()}
  | {:error, {String.t(), non_neg_integer()}}
```

Parses the output of `git cat-file`.

- For `:type` mode, returns `{:ok, atom}` where atom is one of
  `:blob`, `:tree`, `:commit`, or `:tag`.
- For `:size` mode, returns `{:ok, integer}`.
- For `:print` mode (including textconv and filters), returns
  `{:ok, String.t()}`.
- For `:exists` mode, exit code 0 returns `{:ok, true}` and exit
  code 1 returns `{:ok, false}` (not an error).

---

*Consult [api-reference.md](api-reference.md) for complete listing*