LINENO {this.path}

Line Number of Executing Expression

Description

Get the line number of the executing expression.

Usage

LINENO(n = 0, envir = parent.frame(n + 1),
       matchThisEnv = getOption("topLevelEnvironment"),
       srcfile = if (n) sys.parent(n) else 0)

Arguments

n, envir, matchThisEnv, srcfile

See ?this.path().

Details

LINENO() only works if the expressions have a srcref.

Scripts run with Rscript do not store their srcref, even when getOption("keep.source") is TRUE.

For source() and sys.source(), make sure to supply argument keep.source = TRUE directly, or set options "keep.source" and "keep.source.pkgs" to TRUE.

For debugSource() in ‘RStudio’, it has no argument keep.source, so set option "keep.source" to TRUE before calling.

For compiler::loadcmp(), the srcref is never stored for the compiled code, there is nothing that can be done.

For utils::Sweave(), the srcref is never stored, there is nothing that can be done.

For knitr::knit(), the srcref is never stored, there is nothing that can be done. I am looking into a fix.

For package:targets, set option "keep.source" to TRUE before calling associated functions.

For box::use(), plumber::plumb(), shiny::runApp(), and testthat::source_file(), the srcref is always stored.

Value

integer; NA_integer_ if the line number is not found.

Note

You can get a more accurate line number by wrapping LINENO() in braces:

{ LINENO() }

Examples

FILE.R <- tempfile(fileext = ".R")
writeLines(c("
LINENO()
LINENO()
## LINENO() respects #line directives
#line 15
LINENO()
#line 1218
cat(sprintf('invalid value %d at %s, line %d\\n',
            -5, try.this.path(), LINENO()))
"), FILE.R)


if (getRversion() >= "4.3.0") {
    source(FILE.R, echo = TRUE, verbose = FALSE,
        max.deparse.length = Inf, keep.source = TRUE)
} else {
    this.path:::.source(FILE.R, echo = TRUE, verbose = FALSE,
        max.deparse.length = Inf, keep.source = TRUE)
}


unlink(FILE.R)