file.show {base} | R Documentation |
Display one or more files.
file.show(..., header = rep("", nfiles), title = "R Information", delete.file = FALSE, pager = getOption("pager"), encoding = "")
... |
one or more character vectors containing the names of the
files to be displayed. These will be tilde-expanded: see
path.expand . |
header |
character vector (of the same length as the number of files
specified in ... ) giving a header for each file being
displayed. Defaults to empty strings. |
title |
an overall title for the display. If a single separate
window is used for the display, title will be used as the window
title. If multiple windows are used, their titles should combine the title
and the file-specific header. |
delete.file |
should the files be deleted after display? Used for temporary files. |
pager |
the pager to be used: not used on all platforms |
encoding |
character string giving the encoding to be assumed for the file(s). |
This function provides the core of the R help system, but it can be
used for other purposes as well, such as page
.
How the pager is implemented is highly system-dependent.
The basic Unix version concatenates the files (using the headers) to a
temporary file, and displays it in the pager selected by the
pager
argument, which is a character vector specifying a system
command to run on the set of files. The ‘factory-fresh’
default is to use ‘R_HOME/bin/pager’, which is a shell script
running the command specified by the environment variable PAGER
whose default is set at configuration, usually to less
. On a
Unix-alike more
is used if pager
is empty.
Most GUI systems will use a separate pager window for each file, and
let the user leave it up while R continues running. The selection of
such pagers could either be done using special pager names being
intercepted by lower-level code (such as "internal"
and
"console"
on Windows), or by letting pager
be an R
function which will be called with the same first four arguments as
file.show
and take care of interfacing to the GUI.
The R.app
Mac OS X GUI uses its internal pager irrespective
of the setting of pager
.
Not all implementations will honour delete.file
. In
particular, using an external pager on Windows does not, as there is
no way to know when the external application has finished with the
file.
Ross Ihaka, Brian Ripley.
files
,
list.files
,
help
.
file.show(file.path(R.home("doc"), "COPYRIGHTS"))