Create backup copy of file, adding suffix of the date of the file modification (NOT today's date)

cp file file.$(date -d @$(stat -c '%Y' file) "+%y%m%d")
When I go to change a configuration file I always like to make a backup first. You can use "cp -p" to preserve the modification time, but it gets confusing to have file.prev, file.prev2, etc. So I like to add a YYMMDD suffix that shows when the file was last changed. "stat -c %Y" gives you the modification time in epoch seconds, then "date -d @" converts that to whatever format you specify in your "+format" string.
Sample Output
# ls -l
-rw-r--r-- 1 root root 0 Dec 31  2018 file
# cp -p file file.$(date -d @$(stat -c '%Y' file) "+%y%m%d")
 ls -l
-rw-r--r-- 1 root root 0 Dec 31  2018 file
-rw-r--r-- 1 root root 0 Dec 31  2018 file.181231
 

3
By: dmmst19
2019-07-18 18:09:09

2 Alternatives + Submit Alt

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