makeTempFile: Create a temporary text file

In jefferys/JefferysRUtils: My bag of tricks for R coding

Create a temporary text file

Description

Creates a temporary text file whose name will be unique and whose context is whatever lines of text are specified as a character vector. By default these are created in R's session temporary directory. This directory and all its contents are removed automatically when the R session ends. File names contain random characters to make them unique, a prefix and a suffix can be specified. An (existing) directory can also be specified, but unless the directory is a subdirectory of tempdir(), it will not be automatically removed.

Usage

makeTempFile(
  lines = character(0),
  namePrefix = "temp",
  extension = ".txt",
  tempDir = tempdir(),
  eol = "\n"
)

Arguments

lines	The lines of text to put into the file.
namePrefix	The constant part of the temporary file's name, defaults to "temp". Normally followed by some random hex digits to ensure name is unique.
extension	The file extension part of the temporary file's name, defaults to ".txt". The "." must be explicitly specified; this is really just a suffix.
tempDir	The directory the file will be created in. Defaults to R's per-session temporary directory. If this is specified it must exist. If it is not a sub-directory of the tempdir(), it will not be removed automatically.
eol	The end of line character to use when writing content to the file. Defaults to the R platform default. Note, this is not a separator; the last line written to the file will be terminated with this character.

Value

Returns the full-path filename to the temporary text file, which has been created with the provided content. This filename may not be in canonical form. By default this will look like: \<tempDir\>/temp\<random\>.txt. Can change the default namePrefix= "temp" and the extension= ".txt" settings.

Examples

tempFile <- makeTempFile( c("one fish", "two fish") )
readLines( tempFile )
#> [1] "one fish" "two fish"

# Can create files that use other platform line endings.
# (readLines() converts automatically to two lines)
file <- makeTempFile( c("one fish", "two fish"), eol="\r" )
readLines( file )
#> [1] "one fish" "two fish"

# Can create files that use weird line endings
file <- makeTempFile( c("one fish", "two fish"), eol=" <>< " )
# Note: " <>< " is not a standard eol, so readLines() returns everything as one
#   string, plus would warn about not ending file with a normal eol character
#   if warn= FALSE was not set.
readLines( file, warn= FALSE )
#> [1] "one fish <>< two fish <>< "

jefferys/JefferysRUtils documentation built on June 18, 2024, 4:39 a.m.