Read a key-value file (KEY=VALUE) into a named list

Reads a human-editable key-value file in a widely used format (INI/.env-like): KEY=VALUE. Blank lines are ignored. Full-line comments starting with # or ; are ignored. Inline comments are supported for unquoted values when preceded by whitespace, e.g., KEY=123 # comment.

Usage

readKeyValueFile(
  filePath,
  ...,
  inferTypes = TRUE,
  duplicateKeys = c("error", "last", "first"),
  safeKeyCheck = FALSE
)

Arguments

filePath

Path to the key-value file.

...

Currently unused.

inferTypes

Logical; if TRUE, attempts to convert values to logical/integer/numeric and NA. If FALSE, returns character values.

duplicateKeys

How to handle duplicate keys: "error" (default), "last" (keep last occurrence), or "first" (keep first occurrence).

safeKeyCheck

Logical; if TRUE, checks that keys only contain allowed characters. Set to FALSE (default) to allow arbitrary keys, but be aware that this may lead to issues when reading the file back, as keys with special characters may not be parsed correctly.

Value

A named list with parsed values.

Details

Values can be quoted with double quotes. Escape sequences \n, \r, \t, \\, and \" are supported.

UTF-8 handling: The file is read as UTF-8 and all character values are normalized to UTF-8 via enc2utf8().

Examples

if (FALSE) { # \dontrun{
keyValueList <- list(
    STUDY_NAME = "Trial A",
    MAX_PATIENTS = 150L,
    THRESHOLD = 0.075,
    NOTES = "First phase\nSecond phase"
)
filePath <- tempfile(fileext = ".txt")
writeKeyValueFile(
    keyValueList = keyValueList,
    filePath = filePath,
    writeHeader = TRUE,
    sortKeys = TRUE,
    overwrite = TRUE
)
readKeyValueFile(filePath)
} # }