Shell Programming and Scripting

I have files in the ABC_YYYYMMDD.zip format under a directory. Each zip file contains A text file in the ABC_YYYYMMDD.txt format.

I am trying to create a script that will Rename the zip files and their underlying text file replacing the datepart in them with [datepart - 1 day].

For eg: in the case of ABC_20140910.zip, the zip file should be renamed to ABC_20140909.zip and the text file should be renamed to ABC_20140910.txt.

Below is what I have so far. I am sure that there is a more efficient way to accomplish this. Any input is appreciated. Thanks.

Code:

for file in `ls -v $FileNamePrefix*.zip`
do

DATE_PART=$(ls "$file" | grep $FileNamePrefix | grep -oE [[:digit:]]+ )  #strip date part from zip file name.

NEW_DATE_PART=$(date +'%Y%m%d' -d "$DATE_PART - 1 day")  #subtract 1 day from date part above.

unzip -o "$file" -d /tmp   #unzip to /tmp dir 

mv /tmp/"$FileNamePrefix"_"$DATE_PART".txt /tmp/"$FileNamePrefix"_"$NEW_DATE_PART".txt  #rename the txt file.

 zip -d "$FileNamePrefix"_"$DATE_PART".zip "$FileNamePrefix"_"$DATE_PART".txt  #remove the original txt file from the zip file.

zip -j "$FileNamePrefix"_"$DATE_PART".zip /tmp/"$FileNamePrefix"_"$NEW_DATE_PART".txt  #zip back the renamed txt file.
 
mv "$file" $FileNamePrefix"_"$NEW_DATE_PART".zip  #rename the zip file.

done

So, do you mean that you want to edit the zip file and change the file information? If this was a simple unix compressed single file it would not matter, but there is data written within the zip file like a mini-directory holding all the file details. It's the same with tar where multiple files can be collected.

I fear that you may need to extract the file, rename it and re-zip as your script does, however we can tidy up your script a little so that we don't call unnecessary external programs (grep, ls, etc.)

To get your loop started, you can simply:-

Code:

for file in ${FileNamePrefix}*.zip
do

To slice a string with nice clear delimiters, you can use variable substitution. This looks like ksh or bash so:-

Code:

tempvar="${file#*_}"                   # Strip off everything up to the first underscore
DATE_PART="${tempvar%.zip}"           # Strip off the trailing .zip

Date calculations form many threads on this forum. If what you have works for you, then it is probably the neatest you can get already.

When you are zip -d 'removing' the .txt file from the .zip, what will be left in the .zip? If it's nothing, then just remove the .zip file and create a new one of the required name for the extracted .txt



I hope that this helps a little.
Robin