How to List Files by Date in R (With Example)

You can use the following basic syntax to list the files in the current working directory in R by date:

#extract all CSV files in working directory
file_info = file.info(list.files(pattern="*.csv"))

#sort files based on mtime (modification date and time)
file_info = file_info[with(file_info, order(as.POSIXct(mtime))), ]

#view only file names with modification date and time
file_info[c("mtime")]

The following example shows how to use this syntax in practice.

Example: How to List Files by Date in R

Suppose I would like to list all of the CSV files in the current working directory in R by date.

I can use the following syntax to first extract all CSV files (with file information) from the current working directory:

#extract all CSV files in working directory
file_info = file.info(list.files(pattern="*.csv"))

#view all CSV files
file_info

                        size isdir mode               mtime               ctime               atime exe
basketball_data.csv       55 FALSE  666 2023-01-06 11:07:43 2022-07-12 09:07:26 2023-04-18 09:42:19  no
df1.csv                  126 FALSE  666 2022-04-21 10:48:24 2022-04-21 10:48:24 2023-04-18 09:42:19  no
df2.csv                  126 FALSE  666 2022-04-21 10:48:30 2022-04-21 10:48:29 2023-04-18 09:42:19  no
df3.csv                  126 FALSE  666 2022-04-21 10:48:34 2022-04-21 10:48:34 2023-04-18 09:42:19  no
my_data.csv               53 FALSE  666 2022-09-09 09:02:21 2022-04-22 09:00:13 2023-04-18 09:42:19  no
my_list.csv               90 FALSE  666 2022-04-21 09:40:01 2022-04-21 09:39:59 2023-04-18 09:42:19  no
my_test.csv              146 FALSE  666 2022-04-21 09:42:25 2022-04-21 09:42:25 2023-04-18 09:42:19  no
player_stats.csv         137 FALSE  666 2023-04-11 09:07:20 2023-04-11 09:07:20 2023-04-18 09:42:19  no
players_data.csv          50 FALSE  666 2023-01-06 09:44:12 2023-01-06 09:44:12 2023-04-18 09:42:19  no
team_info.csv            131 FALSE  666 2023-04-11 09:07:21 2023-04-11 09:07:21 2023-04-18 09:42:19  no
test.csv            18059168 FALSE  666 2022-09-07 09:07:34 2020-02-01 13:44:03 2023-04-18 09:42:19  no
uneven_data.csv           43 FALSE  666 2023-01-06 14:02:17 2023-01-06 14:00:27 2023-04-18 09:42:19  no

I can then use the order() function to order the files by mtime, which represents the date and time the files were most recently modified:

#sort files based on mtime (modification date and time)
file_info = file_info[with(file_info, order(as.POSIXct(mtime))), ]

#view sorted files
file_info

                        size isdir mode               mtime               ctime               atime exe
my_list.csv               90 FALSE  666 2022-04-21 09:40:01 2022-04-21 09:39:59 2023-04-18 09:42:19  no
my_test.csv              146 FALSE  666 2022-04-21 09:42:25 2022-04-21 09:42:25 2023-04-18 09:42:19  no
df1.csv                  126 FALSE  666 2022-04-21 10:48:24 2022-04-21 10:48:24 2023-04-18 09:42:19  no
df2.csv                  126 FALSE  666 2022-04-21 10:48:30 2022-04-21 10:48:29 2023-04-18 09:42:19  no
df3.csv                  126 FALSE  666 2022-04-21 10:48:34 2022-04-21 10:48:34 2023-04-18 09:42:19  no
test.csv            18059168 FALSE  666 2022-09-07 09:07:34 2020-02-01 13:44:03 2023-04-18 09:42:19  no
my_data.csv               53 FALSE  666 2022-09-09 09:02:21 2022-04-22 09:00:13 2023-04-18 09:42:19  no
players_data.csv          50 FALSE  666 2023-01-06 09:44:12 2023-01-06 09:44:12 2023-04-18 09:42:19  no
basketball_data.csv       55 FALSE  666 2023-01-06 11:07:43 2022-07-12 09:07:26 2023-04-18 09:42:19  no
uneven_data.csv           43 FALSE  666 2023-01-06 14:02:17 2023-01-06 14:00:27 2023-04-18 09:42:19  no
player_stats.csv         137 FALSE  666 2023-04-11 09:07:20 2023-04-11 09:07:20 2023-04-18 09:42:19  no
team_info.csv            131 FALSE  666 2023-04-11 09:07:21 2023-04-11 09:07:21 2023-04-18 09:42:19  no

Note that you could instead use ctime if you’d like to order the files based on creation date instead or atime to order the files based on accessed date.

Lastly, we can subset the data frame to only show the file names along with the date and time they were most recently modified:

#view only file names with modification date and time
file_info[c("mtime")]

                                  mtime
my_list.csv         2022-04-21 09:40:01
my_test.csv         2022-04-21 09:42:25
df1.csv             2022-04-21 10:48:24
df2.csv             2022-04-21 10:48:30
df3.csv             2022-04-21 10:48:34
test.csv            2022-09-07 09:07:34
my_data.csv         2022-09-09 09:02:21
players_data.csv    2023-01-06 09:44:12
basketball_data.csv 2023-01-06 11:07:43
uneven_data.csv     2023-01-06 14:02:17
player_stats.csv    2023-04-11 09:07:20
team_info.csv       2023-04-11 09:07:21

If you’d like, you could also only view the file names in order by date:

#view only file names
rownames(file_info)

 [1] "my_list.csv"         "my_test.csv"         "df1.csv"             "df2.csv"             "df3.csv"            
 [6] "test.csv"            "my_data.csv"         "players_data.csv"    "basketball_data.csv" "uneven_data.csv"    
[11] "player_stats.csv"    "team_info.csv"

The twelve CSV file names are listed in order by date.