Test a file date with bash

I am trying to test how old ago a file was created (in seconds) with bash in an if statement. I need creation date, not modification.

Do you have any idea how to do t开发者_如何学Pythonhis, without using a command like find with grep?

I'm afraid I cann't answer the question for creation time, but for last modification time you can use the following to get the epoch date, in seconds, since filename was last modified:

date --utc --reference=filename +%s

So you could then so something like:

modsecs=$(date --utc --reference=filename +%s)
nowsecs=$(date +%s)
delta=$(($nowsecs-$modsecs))
echo "File $filename was modified $delta secs ago"

if [ $delta -lt 120 ]; then
  # do something
fi

etc..

Update A more elgant way of doing this (again, modified time only): how do I check in bash whether a file was created more than x time ago?

Here is the best answer I found at the time being, but it's only for the modification time :

expr `date +%s` - `stat -c %Y /home/user/my_file`

If your system has stat:

modsecs=$(stat --format '%Y' filename)

And you can do the math as in Joel's answer.

you can use ls with --full-time

file1="file1"
file2="file2"
declare -a array
i=0
ls -go --full-time "$file1" "$file2" | { while read -r  a b c d time f
do    
  time=${time%.*}  
  IFS=":"
  set -- $time
  hr=$1;min=$2;sec=$3
  hr=$(( hr * 3600 ))
  min=$(( min * 60 ))  
  totalsecs=$(( hr+min+sec ))
  array[$i]=$totalsecs  
  i=$((i+1))
  unset IFS      
done
echo $(( ${array[0]}-${array[1]} ))
}