[ We could _really_ use a "practices" list. ;-]
Jerry Geis geisj@pagestation.com wrote:
I am trying to find out how to tell if a given file is 30 days or older.
Do you mean accessed time (atime), changed attributes time (ctime) or modification time (mtime)? I'll assume you want "mtime".
The find command is extremely powerful. E.g., find / -mtime +30
This will give you all files in the system that have been modified over 30 days ago (i.e., 31+).
If you just want to look in the _current_directory_: find . -maxdepth 1 -mtime +30
If you want to look at a particular file: find /home/myfile -maxdepth 0 -mtime +30
If the file is listed, it was last modified 31+ days ago.
How is that type of thing done in shell scripts.
Here's an example script that takes a list of files and moves the files under /home/old (full path and attributes preserved) if they are older than 30 days.
Syntax: fold30 file [file...]
Script:
1: [ "$1" == "" ] && exit 1 2: mylist="$*" 3: for myfile in ${mylist}; do 4: if [ -f "${myfile}" ]; then 5: if [ "`find ${myfile} -mtime +30`" != "" ]; then 6: echo ${myfile} | cpio -pmdvu /home/old/${myfile} 7: rm -f ${myfile} 8: fi 9: fi A: done
The main conditional on line 5 is what does the job. If the result of the find command is not an empty string, then the name was returned and it is older than 30 days. Now move it to the same path under /home/old (using cpio) and remove the original.
NOTE: It will _not_ work if spaces are used in the paths, that's something I've yet to see work correctly (I can never get the "IFS" variable set to work proper in the loop) in bash, so I professionally use tcsh instead. Bash does not seem to work with quotes in a loop like tcsh does, and the Advanced Bash Scripting Guide (ABSG) is just _dead_wrong_ on using quotes for most bash releases (although it works fine across all tcsh versions I've used).