Unix find -mtime {a negative or postive value}

问题

What do find -mtime -4 and find -mtime +4 do? I cannot understand the examples given in the man page.

回答1:

As per man page:

-mtime n
    File’s  data was last modified n*24 hours ago.  See the comments
    for -atime to understand how rounding affects the interpretation
    of file modification times.

The argument to -mtime is interpreted as the number of whole days in the age of the file. -mtime +n means strictly greater than, -mtime -n means strictly less than.

So in your case,

-4 meaning less than 4 days.
+4 meaning more than 4 days i.e. 4*24 hours.

回答2:

Well, I can.

-mtime n

File's data was last modified n*24 hours ago. See the comments for -atime to understand how rounding affects the interpretation of file modification times

find . -mtime 0   # find files modified between now and 1 day ago
                  # (i.e., within the past 24 hours)
find . -mtime -1  # find files modified less than 1 day ago
                  # (i.e., within the past 24 hours, as before)
find . -mtime 1   # find files modified between 24 and 48 hours ago
find . -mtime +1  # find files modified more than 48 hours ago

来源：https://stackoverflow.com/questions/27700943/unix-find-mtime-a-negative-or-postive-value