Create directory named from file modification time

Question

I want to create directory name from a file's modification time. For example, if the file creation or modification time is 03/17/2016 18:00:00 then I want to create a directory named 1703206. I'm using HP-UX.

Answer 1

With only POSIX tools (and HP-UX doesn't have much more than that), this is difficult, because there's no convenient way to get a file's modification time. With ls -l, you need to deal with two cases: recent files with month, day, house and minute, and old files (> 6 months) with month, day and year. (There may be an easier way by crafting an appropriate locale settings but I don't know if that can be done on HP-UX.)

#!/bin/sh
set -e -f
set -- $(LC_ALL=C ls -dlog -- "$1")
# $1=permissions $2=link_count $3=size $4,$5,$6=date_time $7...=filename
case $4 in
  Jan) month=1;;
  Feb) month=2;;
  Mar) month=3;;
  Apr) month=4;;
  May) month=5;;
  Jun) month=6;;
  Jul) month=7;;
  Aug) month=8;;
  Sep) month=9;;
  Oct) month=10;;
  Nov) month=11;;
  Dec) month=12;;
esac
case $6 in
  *:*) # The timestamp is within the last 6 month, so
       # the year is the current or previous year.
    current_month=$(LC_ALL=C date +%Y%m)
    year=${current_month%??}
    current_month=${current_month#????}
    case $current_month in 0*) current_month=${current_month#0};; esac
    if [ $current_month -lt $month ]; then year=$((year-1)); fi;;
  *) year=$6;;
esac
if [ $month -le 9 ]; then month=0$month; fi
day=$5
if [ $day -le 9 ]; then day=0$day; fi
mkdir $year$month$day

If you're using some ancient version of HP-UX where /bin/sh is an old Bourne shell, you may need to replace /bin/sh on the shebang line by the path to a POSIX shell such as ksh.

Answer 2

On Linux, if foo is your file

stat -c %Z foo

will give second since epoch (see man stat, you may use %W, %X, %Y, %Z for creation time, access time, modification time, change time)

date --date=@$(stat -c %Z foo) +%m%d%y

will give your format.

SO

 mkdir bar/prefix$(date --date=@$(stat -c %Z foo) +%m%d%y)suffix

• replace foo, bar, prefix and suffix by actual/desired file name.
• use quote arround var to avoid funny char.