How to find files older than N days from a given timestamp

Question

I want to find files older than N days from a given timestamp in format YYYYMMDDHH

I can find file older than 2 days with the below command, but this finds files with present time:

find /path/to/dir -mtime -2 -type f -ls

Lets say I give the input timestamp=2011093009 I want to find files older than 2 days from 2011093009.

Been doing my research, but can't seem to figure it out.

Should the command to find older than 2 days be `find /path/to/dir -mtime +2 -type f -ls`? I tried this and on my system (xubuntu, bash) the `-2` option to `-mtime` would find files newer than 2 days. — jhonkola, Feb 13 '13 at 11:05
I dislike -mtime because I feel it's too "relative". For a more "absolute" solution, try "touch -t" to create files with the relevant timestamps, and then find's "-newer" and "!" operators. — , Jan 15 '15 at 13:23

score 0 · Answer 1 · edited May 23 '17 at 11:59

0

put one of the answers from here and using $() as suggested here

(updated as per comment by sputnick)

date=2011060109; find /home/kenjal/ -mtime $(( $(date +%Y%m%d%H) - $(date -d $date +%Y%m%d%H) ))

edited May 23 '17 at 11:59

Community

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answered Jun 28 '12 at 15:37

Kinjal Dixit

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`expr` is the old fashion ;) `date=2011060109; find /home/kenjal/ -mtime $(( $(date +%Y%m%d%H) - $(date -d $date +%Y%m%d%H) ))` – Gilles Quénot Jun 28 '12 at 15:50
This requires GNU date of course (the -d option is not portable). Also, I don't think this anwsers the original question; he wants files OLDER than N days from some date. Not sure how to do this myself... – BellevueBob Jun 28 '12 at 16:30
Bob Duell: You a correct, I want files OLDER than N days from some date. And yes, I do not have GNU date, so `-d` option does not work for me – esausilva Jun 28 '12 at 20:46
kinjal: Thanks for your answer, the link you provided guided me to get the correct answer, took me some time, but finally got it :). I'll post it in a bit... – esausilva Jun 28 '12 at 20:47

score 0 · Accepted Answer · answered Jun 28 '12 at 21:06

Basically this is accomplished by finding files in a range of dates...

I used perl to calculate the days from today to the given timestamp since GNU date is not available in my system, so -d is not an option. Code Below accepts date in format YYYYDDMM. See below:

#!/usr/bin/perl 
use Time::Local;

my($day, $month, $year) = (localtime)[3,4,5];
$month = sprintf '%02d', $month+1;
$day   = sprintf '%02d', $day;
my($currentYear, $currentDM) = ($year+1900, "$day$month");
my $todaysDate = "$currentYear$currentDM";
#print $todaysDate;

sub to_epoch {
    my ($t) = @_;  
    my ($y, $d, $m) = ($t =~ /(\d{4})(\d{2})(\d{2})/); 
    return timelocal(0, 0, 0, $d+0, $m-1, $y-1900);
}
sub diff_days {
    my ($t1, $t2) = @_;  
    return (abs(to_epoch($t2) - to_epoch($t1))) / 86400; 
}
print diff_days($todaysDate, $ARGV[0]);

**Note: I'm no expert in Perl and this is the very first piece of code I modify/write. Having said that, I'm sure there are better ways to accomplish the above in Perl

Then the below korn script to perform what I needed.

#!/bin/ksh
daysFromToday=$(dateCalc.pl 20110111)
let daysOld=$daysFromToday+31
echo $daysFromToday "\t" $daysOld

find /path/to/dir/ -mtime +$daysFromToday -mtime -$daysOld -type f -ls

I'm finding all files older than +$daysFromToday, then narrowing the search to days newer than -$daysOld

ormaaj · Answer 3 · 2012-06-30T03:51:22.327

#!/usr/bin/env bash

# getFiles arrayName olderDate newerDate [ pathName ]
getFiles() {
    local i
    while IFS= read -rd '' "$1"'[(_=$(read -rd "" x; echo "${x:-0}")) < $2 && _ > $3 ? ++i : 0]'; do 
        :
    done < <(find "${4:-.}" -type f -printf '%p\0%Ts\0')
}

# main date1 date2 [ pathName ]
main() {
    local -a dates files
    local x
    for x in "${@:1:2}"; do
        dates+=( "$(date -d "$x" +%s)" ) || return 1
    done

    _=$dates let 'dates[1] > dates && (dates=dates[1], dates[1]=_)'
    getFiles files "${dates[@]}" "$3"
    declare -p files
}

main "$@"

# vim: set fenc=utf-8 ff=unix ts=4 sts=4 sw=4 ft=sh nowrap et:

This Bash script takes two dates and a pathname for find. getFiles takes an array name and the files with mtimes between the two dates are assigned to that array. This example script simply prints the array.

Requires a recent Bash, and GNU date. If it really has to be "N days", or you don't have GNU date, then there is no possible solution. You'll need to use a different language. No shell can do that using standard utilities.

Technically, you can calculate an offset in days using printf '%(%s)T' ... and some arithmetic, but there is no possible way to get the base date from a timestamp without GNU date, so I'm afraid you're out of luck.

Edit

I see this question has a ksh tag, in which case I lied, apparently ksh93's printf accepts a GNU date -d like string. I have no idea whether it's portable, and of course requires a system with ksh93 installed. You could do it in that case with some modification to the above script.

thank you for your response...unfortunately, my system does not have GNU date, so `-d` is not an option...but, with a little more research, I have figured out an answer to my question. you can take a look at my accepted answer — esausilva, Jul 03 '12 at 02:11
Yeah that's ok, I noticed in your other comments just as I finished with this. I hope someone finds it useful anyway. — ormaaj, Jul 03 '12 at 02:37

How to find files older than N days from a given timestamp

3 Answers3