[cgjoker]

I know this should be basic unix but im having a heck of a time getting this to work for me for some reason.

I have a file called john1234567.dat

I want to rename it to 1234567

How do I do this?

here is what im trying ...

for FILE in `ls | grep john_*.dat`;
do
$newname="`expr "$FILE" : ':$s/\([john_])([])'`"
mv $FILE $newname
done

[surfnschultz]

cp john1234567.dat 1234567

cat john1234567.dat > 1234567

These are easy, but might not meet your needs. Still looking for more help? let me know.

[cgjoker]

I guess I should have elaborated a bit more.

The filename will never be the same. Each filename will have 7 digits on the end that id want to rename the file to.

thanks.

[Squashman]

Will there always be an undscore between the name and number? Will the filename always start with John_? Makes it real easy if it does.

[cgjoker]

no. the filename will always be different. i just need to get the last 7 characters of the filename, and rename that file to just those 7 characters.

that is kind of why i was trying to do a for loop in my attempt.

[cgjoker]

in my example i know i have john_, but this was just to get it to work. really it should not even have the john_ in the substring.

[Squashman]

Hmmm, not sure. So you want the 7 characters before the file extension and the file extension dropped. Let me clarify one more thing. Will those 7 characters be numbers or random characters.

[Squashman]

I am assuming that the 7 digits will always be there and there will not be any characters in between them.

for FILE in `ls | grep .dat`;
do
newname=`echo $FILE | tr -d "[:alpha:]" | tr -d "."`
mv $FILE $newname
done

I am not sure if this will work for you or not. Basically what this script does is remove all alpha characters from the filename and the period. So hopefully those 7 digits are the only numerics in your filename.

hopefully that is the last time I edit this.

[cgjoker]

I know its a really late reply, but there is a slight change to my requirement.

I actually need to keep the first 8 characters of a filename and drop the rest.

so ET345678file.dat would become ET345678

the first 8 characters would change constantly.

thanks.

[cgjoker]

here is my latest attempt
for FILE in `ls *`;
do
newname=`echo $FILE | head -c9`
mv $FILE $newname
done

[Squashman]

Originally Posted by cgjoker

here is my latest attempt
for FILE in `ls *`;
do
newname=`echo $FILE | head -c9`
mv $FILE $newname
done

Read the manual page for head and you will see why that wont work. But you were close. If you have your script in this directory it will rename your script as well. So I would suggest you move it into a different directory and chang the ls command to the directory you want listed.

for FILENAME in `ls *`;
do
newname=`echo $FILENAME | cut -b-8`
mv $FILENAME $newname
done

[cgjoker]

thanks... I refined it a bit.

for FILENAME in `ls *`;
do
newname=`echo $FILENAME | head -c8`
mv $FILENAME $newname
done

Im finding that your code is doing the same as mine. The problem im having is that both codes are only doing one file. The second or third file is deleted.

So if I have 12345678_file.dat, 34567890_file2.dat....

I get only one file afterwards

12345678

[cgjoker]

Nevermind,... both are working fine.

Thanks for your help

[Squashman]

That is weird that the head command works for you. It is suppose to read the contents of a file and pull the first couple lines or bytes out of it.

[cgjoker]

so... here is my dilemma now.

I have two files with the same first 8 characters so I want to add a number to each filename to make it unique.

Here is what I came up with.

cd /data
for FILENAME in `ls *`;
do
name=`date +%b +%d`
for x in 1 2 3 4 5 6 7 8 9
do
#newname=`echo $FILENAME | head -c8`
newname=`echo $FILENAME | cut -b-8`
mv $FILENAME $newname$name$x
done
done