CODEWITHSUNDEEP
linuxshellunixlogging
JumpOffBox
JumpOffBox

Reputation: 783

shell script to generate new log with date stamp

Is there a way to extract the last modified date and time from a log file and attach that date and time to the file?

I have a tool that generates appslist.log file every time it is run. Through my script when I run the tool, the applist.log file is already there and then I may have to associate it with the time and date it was created.

Like:

mv applist.log applist_+%Y%m%d_%H%M%S.log

Like let's say I ran the tool the first time and it generated applist.log:

applist.log     Mon 03-29-2013

The next time I run the tool on 03-30-2013, I want to move the existing applist.log file with a new name containing the date and time it was created:

like applist_03-29-2013.log

because the tool would again generate applist.log on 03-30-2013.

Upvotes: 1

Views: 9415

Answers (2)

Roland Schindler
Roland Schindler

Reputation: 46

Getting the creation time of a file depends on the file system you're using.
Not all file systems support retrieving file creation time. Try: 

stat --format=%w applist.log

If you get a single '-', your file system does not report the creation time. Otherwise, it prints the time.

If you get the creation time this way, you may use the following to do the move: 

fileName="applist.log"  
creationTimeEpoch="$(stat --format=%W "${fileName}")"  
creationTime="$(date +%Y%m%d_%H%M%S --date="@${creationTimeEpoch}")"  
mv -i "${fileName}" "${fileName%.log}_${creationTime}.log"

If not, you may use the modification time of the file: 

fileName="applist.log"  
modificationTime="$(date +%Y%m%d_%H%M%S --reference="${fileName}")"  
mv -i "${fileName}" "${fileName%.log}_${modificationTime}.log"

Upvotes: 1

Jess
Jess

Reputation: 25069

mv applist.log applist_`date -r applist.log +%Y%m%d%H%M%S`.log

This will move the file to a new file with a date in the name. The date command allows you to display in any format. See man date for a full description of these character sequences. Using back ticks will run the command inside first. The -r option on date will get the date of the file in question.

Example:

[me@host temp]$ mv applist.log applist_`date -r applist.log +%Y%m%d%H%M%S`.log
[me@host temp]$ ls -l
total 196
-rw-rw-r--. 1 me me     0 Mar 25 20:55 applist_20130325205532.log

I assume your program is a cron and will not run more than once a second.

Upvotes: 1

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