Reads lines from a set of text files and returns only the lines that match a specified regular expression pattern. The function processes each file one-by-one to maintain memory efficiency, making it suitable for reading large files. Files that cannot be read (due to warnings or errors) are skipped with a warning.
If verbosity is enabled via seekr.verbose = TRUE and the session is interactive,
the function reports progress.
read_filter_lines(files, pattern, ...)A list with two elements:
line_numberA list of integer vectors giving the line numbers of matching lines, one per file.
lineA list of character vectors containing the matched lines, one per file.
A character vector of files to search (only for seek_in()).
A regular expression pattern used to match lines.
Additional arguments passed to readr::read_lines(), such as
skip, n_max, or locale.
Files are processed sequentially to minimize memory usage, especially when working with
large files. Only the lines matching the pattern are retained for each file.
If a file raises a warning or an error during reading, it is silently skipped and contributes an empty entry to the result lists.