aspell {utils}R Documentation

Spell Check Interface


Spell check given files via Aspell, Hunspell or Ispell.


aspell(files, filter, control = list(), encoding = "unknown",
       program = NULL, dictionaries = character())



a character vector with the names of files to be checked.


an optional filter for processing the files before spell checking, given as either a function (with formals ifile and encoding), or a character string specifying a built-in filter, or a list with the name of a built-in filter and additional arguments to be passed to it. See Details for available filters. If missing or NULL, no filtering is performed.


a list or character vector of control options for the spell checker.


the encoding of the files. Recycled as needed.


a character string giving the name (if on the system path) or full path of the spell check program to be used, or NULL (default). By default, the system path is searched for aspell, hunspell and ispell (in that order), and the first one found is used.


a character vector of names or file paths of additional R level dictionaries to use. Elements with no path separator specify R system dictionaries (in subdirectory ‘share/dictionaries’ of the R home directory). The file extension (currently, only ‘.rds’) can be omitted.


The spell check programs employed must support the so-called Ispell pipe interface activated via command line option -a. In addition to the programs, suitable dictionaries need to be available. See, and, respectively, for obtaining the Aspell, Hunspell and (International) Ispell programs and dictionaries.

The currently available built-in filters are "Rd" (corresponding to RdTextFilter), "Sweave" (corresponding to SweaveTeXFilter), "R", "pot", "dcf" and "md".

Filter "R" is for R code and extracts the message string constants in calls to message, warning, stop, packageStartupMessage, gettext, gettextf, and ngettext (the unnamed string constants for the first five, and fmt and msg1/msg2 string constants, respectively, for the latter two).

Filter "pot" is for message string catalog ‘.pot’ files. Both have an argument ignore allowing to give regular expressions for parts of message strings to be ignored for spell checking: e.g., using "[ \t]'[^']*'[ \t[:punct:]]" ignores all text inside single quotes.

Filter "dcf" is for files in Debian Control File format. The fields to keep can be controlled by argument keep (a character vector with the respective field names). By default, Title and Description fields are kept.

Filter "md" is for files in Markdown format (‘.md’ and ‘.Rmd’ files), and needs packages commonmark and xml2 to be available.

The print method for the objects returned by aspell has an indent argument controlling the indentation of the positions of possibly mis-spelled words. The default is 2; Emacs users may find it useful to use an indentation of 0 and visit output in grep-mode. It also has a verbose argument: when this is true, suggestions for replacements are shown as well.

It is possible to employ additional R level dictionaries. Currently, these are files with extension ‘.rds’ obtained by serializing character vectors of word lists using saveRDS. If such dictionaries are employed, they are combined into a single word list file which is then used as the spell checker's personal dictionary (option -p): hence, the default personal dictionary is not used in this case.


A data frame inheriting from aspell (which has a useful print method) with the information about possibly mis-spelled words.


Kurt Hornik and Duncan Murdoch (2011), Watch your spelling! The R Journal 3(2), 22–28.

See Also

aspell-utils for utilities for spell checking packages.

Package Aspell on Omegahat ( for a fine-grained R interface to the Aspell library.


## Not run: 
## To check all Rd files in a directory, (additionally) skipping the
## \references sections.
files <- Sys.glob("*.Rd")
aspell(files, filter = list("Rd", drop = "\\references"))

## To check all Sweave files
files <- Sys.glob(c("*.Rnw", "*.Snw", "*.rnw", "*.snw"))
aspell(files, filter = "Sweave", control = "-t")

## To check all Texinfo files (Aspell only)
files <- Sys.glob("*.texi")
aspell(files, control = "--mode=texinfo")

## End(Not run)

## List the available R system dictionaries.
Sys.glob(file.path(R.home("share"), "dictionaries", "*.rds"))

[Package utils version 3.5.0 Index]