how to remove all tabs and newline (\n)

Shell Programming and Scripting
1

how to remove all tabs and newline (\n) from the exicting file

2 
tr -d '\011\012' <existing >new

Not all variants of tr understand the \000 octal notation; if so, read your local tr man page to find out what to use instead. Popular alternatives are C-like annotations, where \t is tab and \n is newline.

3

try this
sed -e 's/
//g' -e 's/[TAB]//g' filename
or
sed 's/[TAB]\|
//g' filename