Function fill_list 

pub(crate) fn fill_list(
    path: &Path,
    regex: &Regex,
    exclude_regex: Option<&Regex>,
    expr_root: Option<&ExprNode>,
    opts: &Options,
    stats: &mut Stats,
    files: &mut Vec<String>,
    depth: i32,
)

Recursively walk a directory and collect all matching file paths into files.

This is the list-all counterpart to add_directory(). Instead of executing a command for each match, it appends the full path of every matched entry to the files vector. The caller then joins these paths and invokes the command template once via proc_cmd() with %0 expanded to the entire list.

Arguments

• path — the directory to scan
• regex — compiled regex matched against each entry’s full path
• exclude_regex — optional compiled exclude pattern
• expr_root — optional parsed expression tree (from --expr)
• opts — runtime options (depth, hidden, filters, etc.)
• stats — mutable execution statistics (files_matched is incremented)
• files — accumulator for matched file paths
• depth — current recursion depth (0 at the root call)