Find string pattern in (text) file

Find string pattern in (text) file

find_pattern_in(file_contents, basedir = ".", dir_recursive = TRUE,
  reader = readLines, include.comments = FALSE, comment.char = NULL,
  use.OS = FALSE, file_pattern = "\\.(R|r)(nw|md)?$",
  file_contents_perl = TRUE, file_contents_fixed = FALSE,
  file_contents_ignore_case = FALSE, file.ext = NULL,
  which_lines = c("first", "all"))

Arguments

file_contents	A perl-regular expression as a search query.
basedir	The root of the directory tree in which files will be searched recursively.
dir_recursive	(logical, default: TRUE) Search within subdirectories of basedir?
reader	A function, akin to base::readLines, the default, that accepts a filename and returns a character vector.
include.comments	If FALSE, the default, comments (i.e. anything after a \#) are not searched.
comment.char	If include.comments is FALSE, what character marks a comment character? By default, NULL, which sets the correct comment symbol for R and TeX files.
use.OS	Use the operating system to determine file list. Only available on Windows. If it fails, a fall-back option (using dir) is used.
file_pattern	A regular expression passed to list.files(pattern = file.ext). By default, "\.(R|r)(nw|md)?$", i.e. all R and Sweave files. (Does not have to be a file extension.)
file_contents_perl	(logical, default: TRUE) Should file_contents be interpreted as a perl regex?
file_contents_fixed	(logical, default: FALSE) Should file_contents be interpreted as a fixed regex?
file_contents_ignore_case	(logical, default: FALSE) As in grep.
file.ext	A file extension passed to the operating system if use.OS is used.
which_lines	One of "first" and "all". If "first" only the first match in any file is returned in the result; if "all", all matches are.

Value

A data.table, showing the matches per file.

Details

For convenience, if file_contents appears to be a directory and basedir does not, the arguments are swapped, but with a warning.