Shell Programming and Scripting

Originally Posted by Don Cragun

Hi onenessboy,
You can start by showing us the complete, exact output produced by the command:

Code:

df -P /backup

If the output from the above command doesn't complain about an unknown -P option, the percentage of space used on the filesystem containing /backup should be in field #5 on line #2 of the output from the above command.

If it does complain about an unknown -P option, show us the complete, exact output from the command:

Code:

df /backup

so we can figure out which field and line we need to examine to determine if you have reached your goal.

Hi RudiC,
Why not:

Code:

ls -r1 2[0-9][0-9][0-9][01][0-9][0-3][0-9]_[0-2][0-9][0-5][0-9].tar.gz | awk -F_ 'T[$1]++ {print "echo rm " $0}'  | sh

Because that will remove old files from the most recent date first. And onenessboy wants to remove old backup files from the oldest date first. And he wants to add code to exit the script when the capacity on that filesystem drops below 60% after each date change when one or more backup files were removed for any given date.

Originally Posted by RudiC

Didn't you say the disk was 300GB? Looks more like 500GB...?


EDIT: Does your OS provide the stat command?

Originally Posted by RudiC

Assuming the stat command on your system allows for the -f (--file-system) option, and shamelessly stealing from Don Cragun's earlier post, and NOT being able to ultimately test this on my system, I'd propose this (printing some meaningful numbers for debug purposes) and ask you to comment back:

Code:

{ cd /backup; stat -fc"%b %a %S" .; stat -c"%n %b %B" 2018*.tar.gz | sort; } | awk '
NR == 1         {print Needed = ($1 * PCT - $2) * $3 
                 next
                }

                {split ($1, T, "_")
                 if (T[1] == KnownTime) print "echo rm " LastFile
                 KnownTime = T[1]
                 LastFile = $1
                 print SUM += $2 * $3
                 if (SUM >= Needed) exit
                }
 ' PCT=0.4

Once happy with what is delivered, we can pipe this into an sh command to be executed.