textConnection

R Base 3.6.2

Input and output text connections.

Syntax

textConnection(object, open = "r", local = FALSE,
               encoding = c("", "bytes", "UTF-8"))<p></p><p>textConnectionValue(con)</p>

Arguments

Parameter	Description
`object`	character. A description of the connection. For an input this is an R character vector object, and for an output connection the name for the R character vector to receive the output, or NULL (for none).
`open`	character string. Either "r" (or equivalently "") for an input connection or "w" or "a" for an output connection.
`local`	logical. Used only for output connections. If TRUE, output is assigned to a variable in the calling environment. Otherwise the global environment is used.
`encoding`	character string, partially matched. Used only for input connections. How marked strings in object should be handled: converted to the current locale, used byte-by-byte or translated to UTF-8.
`con`	An output text connection.

Return Value

For textConnection, a connection object of class "textConnection" which inherits from class "connection". For textConnectionValue, a character vector.

Details

An input text connection is opened and the character vector is copied at time the connection object is created, and close destroys the copy. object should be the name of a character vector: however, short expressions will be accepted provided they deparse to less than 60 bytes. An output text connection is opened and creates an R character vector of the given name in the user's workspace or in the calling environment, depending on the value of the local argument. This object will at all times hold the completed lines of output to the connection, and isIncomplete will indicate if there is an incomplete final line. Closing the connection will output the final line, complete or not. (A line is complete once it has been terminated by end-of-line, represented by "\n" in R.) The output character

Examples

Example

# NOT RUN {
zz <- textConnection(LETTERS)
readLines(zz, 2)
scan(zz, "", 4)
pushBack(c("aa", "bb"), zz)
scan(zz, "", 4)
close(zz)

zz <- textConnection("foo", "w")
writeLines(c("testit1", "testit2"), zz)
cat("testit3 ", file = zz)
isIncomplete(zz)
cat("testit4\n", file = zz)
isIncomplete(zz)
close(zz)
foo

# }
# NOT RUN {
# capture R output: use part of example from help(lm)
zz <- textConnection("foo", "w")
ctl <- c(4.17, 5.58, 5.18, 6.11, 4.5, 4.61, 5.17, 4.53, 5.33, 5.14)
trt <- c(4.81, 4.17, 4.41, 3.59, 5.87, 3.83, 6.03, 4.89, 4.32, 4.69)
group <- gl(2, 10, 20, labels = c("Ctl", "Trt"))
weight <- c(ctl, trt)
sink(zz)
anova(lm.D9 <- lm(weight ~ group))
cat("\nSummary of Residuals:\n\n")
summary(resid(lm.D9))
sink()
close(zz)
cat(foo, sep = "\n")
# }