Read a file context as lines

Reads a file being audited into the character vector its analyzers work on.

Usage

read_code(path)

Arguments

path

Absolute path to the file to read.

Value

A list with two elements:

lines

Character vector of lines, or NULL when the file could not be read.

error

NULL when the whole file was read, otherwise a character message. A message with lines present means the file was read but part of it could not be scanned.

Security considerations

A file being audited is untrusted input, so two protections apply. A file larger than 10 MB is not read at all: reading an arbitrarily large file into memory would let a malformed or hostile package exhaust the auditing machine. Lines that are not valid UTF-8 are replaced with an empty line rather than dropped, since dropping them would shift the line numbers of everything after them, and matching against them would fail for the whole file.

Both cases are reported through error, so the scan records the coverage it lost instead of reporting a clean read of a file it never fully examined.