UNIX for Dummies Questions & Answers

I want to find all files in current directory having last modified date less than specific date which I am getting as output of some command in "MMM DD" format... Problem is, I am not able to compare this date with ls -l output. I am also not able to use find command as I am not able to convert date from string format... Kindly let me know if anyone knows...

"some command" produces a date. What is the "some command"? Commands like date let you specify what you get.

Attempting to interpret what is needed -- list of files that are older than a specific date/time:

Code:

#! /bin/ksh

NAME=$(basename ${0})
FILE=$(mktemp --tmpdir ${NAME}.XXXXXX)

trap "rm -f ${FILE}" EXIT

TIME="${1}"
shift

touch -t "${TIME}" ${FILE}
find "${@}" -type f ! -newer ${FILE} -print

The first argument is the time in the format [[CC]YY]MMDDhhmm[.ss], the second and subsequent arguments are directories.

Idea looks good - make a temp file with that date and then use find command to search required files....

But, making temp file requires time in MMDDhhmm format and we have time in "MMM DD" format ("Dec 20"). I don't want to write a function to convert externally
Jan -> 01
Feb -> 02
...
...
Do we have any built in conversion function?
Also,
I want to find files older than specified date, not newer files.... In find command, we can use "-newer" option but we don't have "-older" option.

---------- Post updated at 12:40 PM ---------- Previous update was at 12:33 PM ----------


"Some command" - we have a local command which produces output in "MMM DD" format (eg "Dec 20"). Using this, I want to schedule a cron to move older files to archive directory...

What Operating System and version are you running?
What Shell are you using?
Do you have a High Level Programming Language available?
Do you have use of "perl", "awk" or other quick programming tools?

Further to Jim Mcnamara, what is the "some command" ? Is it something which can be changed to produce a date in a more usable format - preferably including the year too? Is it written in a language which could be used to convert the date? Is the date output from "some command" created on that very day (in which case the process could perhaps output a timestamp file)?

If the date format cannot be changed what is the precise format for a single digit day (leading zero?, month two spaces day?, month space day?).

To answer one of you questions in mainstream "find" the effect of "-older" is achieved by negating "-newer". If your date actually comes from "ls" command we could of course refer to the file itself not a directory listing of the file.


Example of one way to convert character month to numeric month:
This script is an example which also tests itself for every possible month name. There are other more clever Shell techniques available which are less portable.

Code:

for MMM in "Jan" "Feb" "Mar" "Apr" "May" "Jun"\
           "Jul" "Aug" "Sep" "Oct" "Nov" "Dec"
do
        case "${MMM}" in
                "Jan")  MM="01" ;;
                "Feb")  MM="02" ;;
                "Mar")  MM="03" ;;
                "Apr")  MM="04" ;;
                "May")  MM="05" ;;
                "Jun")  MM="06" ;;
                "Jul")  MM="07" ;;
                "Aug")  MM="08" ;;
                "Sep")  MM="09" ;;
                "Oct")  MM="10" ;;
                "Nov")  MM="11" ;;
                "Dec")  MM="12" ;;
        esac
        #
        echo "${MMM}:${MM}"
done

Jan:01
Feb:02
Mar:03
Apr:04
May:05
Jun:06
Jul:07
Aug:08
Sep:09
Oct:10
Nov:11
Dec:12

If you read the touch manpage, you will see that the --date option will take human-friendly dates.

Looks like I will be able to complete desired job with the details provided in this forum. Thank you all.