R/parse_config.R

In nickodell/rmyloginpath: Read Encrypted MySQL Config Files

# Taken from the R package 'ini'
# Modified to read in-memory files, and to handle
# quoted keys.
# Copyright (c) 2016 David Valentim Dias
# GPLv3 Licenced - see LICENSE.txt for more


#' Read and parse .ini file to list
#'
#' @param fileText text of file to parse
#'
#' @details Lines starting with '#' or ';' are comments and will not be parsed
#'
#' @return List with length equivalent to number of sections, each section is
#' a new list
read_mysql_ini <- function(fileText) {
  index <- function(x, rune) {
    equalPosition <- numeric(1)
    for (pos in 1:nchar(x)) {
      if (strsplit(x, "")[[1]][pos] == rune) {
        equalPosition <- pos
        break
      }
    }
    return(equalPosition)
  }
  # internal helper function to find where a character occur

  sectionREGEXP <- "^\\s*\\[\\s*(.+?)\\s*]"
  # match section and capture section name

  keyValueREGEXP <- "^\\s*[^=]+=.+"
  # match "key = value" pattern

  ignoreREGEXP <- "^\\s*[;#]"
  # match lines with ; or # at start

  trim <- function(x) sub("^\\s*(.*?)\\s*$", "\\1", x)
  # amazing lack of trim at old versions of R

  ini <- list()

  lines <- strsplit(fileText, "\n", fixed = TRUE)[[1]]

  for (line in lines) {

    if (grepl(ignoreREGEXP, line)) {
      next
    }

    if (grepl(sectionREGEXP, line)) {
      matches <- regexec(sectionREGEXP, line)
      lastSection <- regmatches(line, matches)[[1]][2]
    }

    if (grepl(keyValueREGEXP, line)) {
      key <- trim(paste0(strsplit(line, "")[[1]][1:(index(line, "=") - 1)], collapse = ""))
      value <- trim(paste0(strsplit(line, "")[[1]][(index(line, "=") + 1):nchar(line)], collapse = ""))
      if (startsWith(value, '"') & endsWith(value, '"')) {
        # Strip beginning and ending quotes
        value <- substr(value, 2, nchar(value) - 1)
        # Replace escaped quotes with quotes
        value <- sub('\\"', '"', value, fixed = TRUE)
      }

      ini[[lastSection]] <- c(ini[[lastSection]], list(key = value))
      names(ini[[lastSection]])[match("key", names(ini[[lastSection]]))] <- key
    }
  }

  ini
}