How to delete a substring using shell script

Question

I have strings called:

abc.out def.out 

How do I delete the substring

.out

In these strings?

What command should I use? (Bourne Shell)

Answer 1

Multiple ways, a selection:

str=abc.out

Shell:

echo ${str%.*} 

Grep:

echo $str | grep -o '^[^\.]*' 

Sed:

echo $str | sed -E 's/(.*?)\..*/\1/' 

Awk:

echo $str | awk -F. '{print $1}' 

-F. means split the string by . and $1 means the first column.

Cut:

echo $str | cut -d. -f1

All output:

abc