filter filenames in R according to pattern-CodePudding

I have a list of files in a directory with the format

Firstname-Lastname-DateofBirth-ID.pdf

for example Tom-Hanks-01.01.1960-5555.pdf The ID is up to now a 4 digit number but it can be a 5 or 6 digit in the future.

i have a vector of IDs, whose corresponding pdf files I would like to move to another directory

I would like R to read the list of files in directory , identify from the filename the ID, check if the ID is in the vectors of IDs to move and if yes move the file.

I can do the latter part with an if() , %in% and system(). How can do the filtering?

tidyverse solution preferred.

Excuse me if I cannot provide a reproducible example. However, just the reading of the filenames and extraction of the ID from the filename alone would help.

CodePudding user response：

Suppose we have the following text files in the current working directory.

$ ls *.txt

Tom-Hanks-01.01.1960-11.txt  
Tom-Hanks-01.01.1960-88.txt    
Tom-Hanks-01.01.1960-4444.txt
Tom-Hanks-01.01.1960-5555.txt
Tom-Hanks-01.01.1960-123456.txt

And I want to move files with ID 111, 222, 5555, 88 and 123456 to a folder in the current wd named dest. So we can do the following,

library(fs)
library(stringr)

# grab the text files
files <- fs::dir_ls(".", glob = "*.txt")
id_to_move <- c(111, 222, 5555, 88, 123456)

# match the pattern which files we need to move.
files_to_move <- files[str_extract(files, "(?<=-)\\w (?=.txt)") %in% id_to_move]

# move the file.
fs::file_move(files_to_move, "dest")

$ ls dest

Tom-Hanks-01.01.1960-123456.txt  
Tom-Hanks-01.01.1960-5555.txt  
Tom-Hanks-01.01.1960-88.txt

CodePudding user response：

with base R:

    filelist <- list.files(pattern = "*.csv")
    
    filelist
    [[1]]
    [1] "Tom-Hanks-01.01.1960-11.pdf"
    
    [[2]]
    [1] "Tom-Hanks-01.01.1960-88.pdf"
    
    [[3]]
    [1] "Tom-Hanks-01.01.1960-4444.pdf"
    
    [[4]]
    [1] "Tom-Hanks-01.01.1960-5555.pdf"
    
    [[5]]
    [1] "Tom-Hanks-01.01.1960-123456.pdf"

idsToMove <- c(1111, 2222, 3333, 4444, 5555)

toMove <- filelist[sapply(filelist, FUN = \(x) strsplit(x=x, split = "-|.pdf", perl=TRUE)[[1]][4] %in% idsToMove)]

> toMove
[[1]]
[1] "Tom-Hanks-01.01.1960-4444.pdf"

[[2]]
[1] "Tom-Hanks-01.01.1960-5555.pdf"