Re: [Help-bash] Help With School Assignment, Learning Bash Scripts

[nick]

I will look into the links for learning more about shell scripting , on the 
other hand I 
unable to figure out how to do this part of the assignment too and have goggled 
various 
questions but to not valid. I will paste the parts of the question below.
Cheers Nick 
1.Modify the command substitution that's being used to create the loop values
that will be placed into the "filename" variable.

Instead of just an "ls $1", pipe the output into a "grep".  The "grep"
will search for all filenames that DO NOT end in ".old".  This can easily
be done with the "grep -v" option.

With this approach, you can get rid of the "echo ... | grep ..."  and the
"if" control structure inside the loop, and simply do the rename.

Again, check that your script works correctly.

Here is my code so far:
!/bin/bash 
shopt -s extglob nullglob
dir=$1
for file in "$dir"/!*(.old)
do
    [[ $file == *.old ]] || mv -- "$file" "$file.old"
done    
On 14-11-06 08:15 AM, Greg Wooledge wrote:
> On Wed, Nov 05, 2014 at 07:46:41PM -0800, Eduardo A. Bustamante López wrote:
>> I don't want to make this explanation long, so I'll just give you
>> some links you can read on why I said that:
>>
>> - 
>> http://mywiki.wooledge.org/BashGuide/TestsAndConditionals#Conditional_Blocks
>> - http://wiki.bash-hackers.org/syntax/ccmd/if_clause
>> - http://mywiki.wooledge.org/glob#extglob 
> 
> I'd add one more:
> 
> http://mywiki.wooledge.org/BashFAQ/054 -- How can I tell whether a variable
> contains a valid number?
>