Referencing variables in commands

mharley · #1 (**permalink**) 03-30-2005

The script I am writing must be able to run several commands (tar, gzip etc) on filenames that are supplied by variables. I am unsure as to what syntax is required/ideal when referencing variables in filenames. The following is a sample command that I would like the script to execute:

Code:

tar cvf bk{fileName}.${DATEyear}${DATEmonth}.tar {fileName}.${DATEyear}${DATEmonth}* >> /ebccsBackupReport.txt

Is this really poor form? The tar filename format must be bkFILENAME.YEARMONTH.tar, where the filename, year and month are variables set earlier in the script.

Also, is there a way to verify where one or more files bearing a variation on a filename exist within the directory? For example, all files under filename.*? I have been using

Code:

if [ -f filename.* ]

but I've been told that this statement is intended more for verifying the existance of a single file, not a range of files.

I'm using Ksh 88 under Solaris 8.

Thanks for all the help.

moxxx68 · #2 (**permalink**) 03-30-2005

var=`date +%m-%Y`
touch filename.$var

tar -cvzf --backup bk.filename.$var.$var.tgz ./filename.$var.$var* >> ebccsbackureport.txt......

file=`find -name "filename" -print`
if [ -e $file ]
then
echo $file
fi

somewhat of a quick reply hope it helps...

zazzybob · #3 (**permalink**) 03-30-2005

Quote:

Originally Posted by mharley

The script I am writing must be able to run several commands (tar, gzip etc) on filenames that are supplied by variables. I am unsure as to what syntax is required/ideal when referencing variables in filenames. The following is a sample command that I would like the script to execute:

Code:

tar cvf bk{fileName}.${DATEyear}${DATEmonth}.tar {fileName}.${DATEyear}${DATEmonth}* >> /ebccsBackupReport.txt

Almost there, but you'd need a $ before {filename} so that the variable's value is evaluated, like you've done with the DATEyear and DATEmonth variables. Apart from that, spot on.

Quote:

Originally Posted by mharley

Also, is there a way to verify where one or more files bearing a variation on a filename exist within the directory? For example, all files under filename.*? I have been using

Code:

if [ -f filename.* ]

but I've been told that this statement is intended more for verifying the existance of a single file, not a range of files.

This really depends on exactly what you're looking for... say if I had some files in my current directory named file1, file2, file3, filen, etc.... you could check how many files match a certain pattern (i.e. which contain the string "file") using find and piping through wc.... Then check that value...

Code:

number=`find . -name "*file*" -prune -print | wc -l`
[[ "$number" -gt "0" ]] && echo "Files found"

Cheers
ZB

Just Ice · #4 (**permalink**) 03-31-2005

Quote:

Originally Posted by mharley

Also, is there a way to verify where one or more files bearing a variation on a filename exist within the directory? For example, all files under filename.*? I have been using

Code:

if [ -f filename.* ]

but I've been told that this statement is intended more for verifying the existance of a single file, not a range of files.

... this line will hold true if any file in the directory starts with "filename." so you will actually see what you're looking for if at least one of them exists in the directory ... verify this with ...

Code:

root_box:/tmp # touch filename.1 filen.1 filename.3 file.3 file4
root_box:/tmp # ls file*
file.3      file4       filen.1     filename.1  filename.3
root_box:/tmp # if [ -f filename.* ]
> then
>     ls filename.*
> else
>     ls           
> fi
filename.1  filename.3
root_box:/tmp # rm filename.1 filename.3
root_box:/tmp # ls
file.3          filen.1         orbit-root      speckeysd.lock
file4           mpHyay4c        plugtmp
root_box:/tmp # ls file*
file.3   file4    filen.1
root_box:/tmp # if [ -f filename.* ]
> then
>     ls filename.*
> else
>     ls           
> fi
file.3          filen.1         orbit-root      speckeysd.lock
file4           mpHyay4c        plugtmp
root_box:/tmp #

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