R：選擇一個具有特定名稱和最近更新的文件

Question

我想選擇一個像下面這行那樣的文件，但沒有按照我的意願去做。

which(substr(rownames(fInfo),1,8) == "mySource") & which.max(fInfo$mtime) 

在一個英語句子，我想選擇的文件的名字開始與「MYSOURCE」並在那些被選擇，我要挑最近更新的文件。

以下我的腳本就足夠了，但它太長了。有人可以縮短我的腳本嗎？

# create dummy files under Folder "scriptFld" 
ifelse(!dir.exists(file.path("scriptFld")), dir.create(file.path("scriptFld")), FALSE) 
strTime = format(Sys.time(), "%H%M") 
file.create(NA, paste0("scriptFld/mySource1_", strTime,".R")); Sys.sleep(1) 
file.create(NA, paste0("scriptFld/mySource2_", strTime,".R")); Sys.sleep(1) 
file.create(NA, paste0("scriptFld/notMySource3_", strTime,".R")) 


# read source R files 
setwd("scriptFld") 
fInfo = file.info(list.files()) # find all files under the folder "scriptFld" 
iCandidate = which(substr(rownames(fInfo),1,8) == "mySource") # focus on file names starting with "source" 
iCandidateMax = iCandidate[ which.max(fInfo$mtime[iCandidate]) ] # choose the most recent file 
fSourceName = rownames(fInfo)[iCandidateMax] 
source(file = fSourceName) # This is what I want, except the script is too long. 
setwd("..") 
(fSourceName) 

Answer 1

你可以這樣做：

library(dplyr) 
files <- list.files("scriptFld", pattern = "^mySource", full.names = TRUE) 
files %>% 
    file.info() %>% 
    pull(mtime) %>% 
    which.max() %>% 
    files[.] %>% 
    source()