Shell Programming and Scripting

why this two loops are not listing same files ?

Code:

for pkg in `ls | grep ".rpm"`
    do
       echo $pkg
    done

Code:

for pkg in `ls | grep "*.rpm"`
    do
       echo $pkg
    done

Could be because
does not make much sense in terms of Regular Expressions. When using grep, you use Regular Expressions, not shell wildcards.

Try this instead:

Code:

.... grep ".*\.rpm"`

With shell metacharacters like * you specify "any amount or none of any type of character".
In Regular Expressions you write the same with ".*" which means

Code:

.     Any single character of any type
*     Any amount of the previous character

Since the dot is a special character in the Regular Expressions, you have to escape it with a backslash when you want it being recognized and not substituted.

Also you could just leave the grep out and do something like "ls *.rpm".

the first useless use of grep we noticed this year