Function replace_all_in_file 

pub fn replace_all_in_file(
    file_path: &Path,
    search: &SearchType,
    replace: &str,
    multiline: bool,
) -> Result<bool>

Performs search and replace operations in a file

When multiline is enabled: reads the entire file into memory and performs replacements spanning multiple lines. When multiline is disabled: reads line-by-line and performs replacements within lines.

Arguments

• file_path - Path to the file to process
• search - The search pattern (fixed string, regex, or advanced regex)
• replace - The replacement string
• multiline - Whether to enable multiline replacement (whole-text matching)

Returns

• Ok(true) if replacements were made in the file
• Ok(false) if no replacements were made (no matches found)
• Err if any errors occurred during the operation