===========================================================================
SED - Changing all letters --> 's/i/I/g' --> Global Replacement
===========================================================================
[adimulamvenkat19851609@cxln4 ~]$ cat>hello.sh
SED - Changing all letters --> 's/i/I/g' --> Global Replacement
===========================================================================
[adimulamvenkat19851609@cxln4 ~]$ cat>hello.sh
#! /bin/bash
#Changing all letters --> 's/i/I/g'
echo "enter filename to substitute using sed"
read fileName
if [[ -f $fileName ]]
then
cat filegrep.txt | sed 's/i/I/g' | head -5 > newfile.txt
else
echo "$fileName doesn't exist"
fi
[adimulamvenkat19851609@cxln4 ~]$ sh hello.sh
enter filename to substitute using sed
filegrep.txt
[adimulamvenkat19851609@cxln4 ~]$ cat newfile.txt
ThIs Is LInux 2000
ThIs Is WIndows 3000
ThIs Is MAC 4000
ThIs Is LInux 2000
ThIs Is WIndows 3000