the name of a file to read data values from. If thespecified file is"", then input is taken from the keyboard(or whateverstdin() reads if input is redirected orR is embedded).(In this case input can be terminated by a blank line or an EOFsignal,Ctrl-D on Unix andCtrl-Z on Windows.)

Otherwise, the file name is interpretedrelative to thecurrent working directory (given bygetwd()),unless it specifies anabsolute path.Tilde-expansion is performed where supported.When runningR from a script,file = "stdin" can be used torefer to the process'sstdin file stream.

This can be a compressed file (seefile).

Alternatively,file can be aconnection,which will be opened if necessary, and if so closed at the end ofthe function call. Whatever mode the connection is opened in,any of LF, CRLF or CR will be accepted as the EOL marker for a lineand so will matchsep = "\n".

file can also be a complete URL. (For the supported URLschemes, see the ‘URLs’ section of the help forurl.)

To read a data file not in the current encoding (for example aLatin-1 file in a UTF-8 locale or conversely) use afile connection setting itsencoding argument(orscan'sfileEncoding argument).

the type ofwhat gives the type of data tobe read. (Here ‘type’ is used in the sense oftypeof.) The supported types arelogical,integer,numeric,complex,character,raw andlist. Ifwhat is a list, it isassumed that the lines of the data file are records each containinglength(what) items (‘fields’) and the list componentsshould have elements which are one of the first six (atomic)types listed orNULL, see section ‘Details’ below.

the maximum number of data values to be read, or ifwhat is a list, the maximum number of records to be read. Ifomitted or not positive or an invalid value for an integer(andnlines is not set to a positive value),scan willread to the end offile.

integer: the maximum number of data values to be read, defaulting tono limit. Invalid values will be ignored.

by default, scan expects to read ‘white-space’delimited input fields. Alternatively,sep can be used tospecify a character which delimits fields. A field is alwaysdelimited by an end-of-line marker unless it is quoted.

If specified this should be the empty character string (the default)orNULL or a character string containing just one single-bytecharacter.

the set of quoting characters as a single characterstring orNULL. In a multibyte locale the quoting charactersmust be ASCII (single-byte).

decimal point character. This should be a character stringcontaining just one single-byte character. (NULL and azero-length character vector are also accepted, and taken as thedefault.)

the number of lines of the input file to skip beforebeginning to read data values.

if positive, the maximum number of lines of data to be read.

character vector. Elements of this vector are to beinterpreted as missing (NA) values. Blank fields arealso considered to be missing values in logical, integer, numericand complex fields. Note that the test happensafter white space is stripped from the input, sona.strings values may need their own white space stripped in advance.

logical: ifTRUE,scan will flush to theend of the line after reading the last of the fields requested.This allows putting comments after the last field, but precludesputting more that one record on a line.

logical: ifTRUE,scan will implicitly addempty fields to any lines with fewer fields than implied bywhat.

vector of logical value(s) corresponding to itemsin thewhat argument. It is used only whensep hasbeen specified, and allows the stripping of leading and trailing‘white space’ fromcharacter fields (numeric fieldsare always stripped). Note: white space inside quoted strings isnot stripped.

Ifstrip.white is of length 1, it applies to all fields;otherwise, ifstrip.white[i] isTRUEand thei-th field is of mode character (becausewhat[i] is)then the leading and trailing unquoted white space from fieldi isstripped.

logical: ifFALSE (default), scan() will print aline, saying how many items have been read.

logical: ifTRUE blank lines in theinput are ignored, except when countingskip andnlines.

logical. Only used ifwhat is a list. IfFALSE, all of a record must appear on one line (but more thanone record can appear on a single line). Note that usingfill = TRUEimplies that a record will be terminated at the end of a line.

character: a character vector of length onecontaining a single character or an empty string. Use"" toturn off the interpretation of comments altogether (the default).

logical. Should C-style escapes such as\n be processed (the default) or read verbatim? Note that ifnot within quotes these could be interpreted as a delimiter (but notas a comment character).

The escapes which are interpreted are the control characters\a, \b, \f, \n, \r, \t, \v and octal andhexadecimal representations like\040 and\0x2A. Anyother escaped character is treated as itself, including backslash.Note that Unicode escapes (starting\u or\U: seeQuotes) are never processed.

character string: if non-empty declares theencoding used on a file (not a connection nor the keyboard) so thecharacter data can be re-encoded. See the ‘Encoding’ sectionof the help forfile, and the ‘R DataImport/Export Manual’.

encoding to be assumed for input strings. If thevalue is"latin1" or"UTF-8" it is used to markcharacter strings as known to be in Latin-1 or UTF-8: it is not usedto re-encode the input (seefileEncoding).See also ‘Details’.

character string: iffile is not supplied and this is,then data are read from the value oftext via a text connection.

logical: should nuls be skipped when reading characterfields?