cat -n file.txt
-- to delete last line in the file :-
sed -i '$d' filename
-- to delete first line in the file :-
sed -i '1d' filename
-- to append something
[root@localhost ~]# sed -i '$a\
> export ORACLE_HOME=/u02/ogg19c\
> export PATH=$ORACLE_HOME/bin:$PATH\
> export LD_LIBRARY_PATH=$ORACLE_HOME/lib
> ' bash_profile
[root@localhost ~]# cat bash_profile
india
is my country
export ORACLE_HOME=/u02/ogg19c
export PATH=$ORACLE_HOME/bin:$PATH
export LD_LIBRARY_PATH=$ORACLE_HOME/lib
in above :- $ taken for last line of the file so append in the last.
-- to delete lines from file using sed command
[root@localhost ~]# cat -n bash_profile
1 india
2 is my country
3 export ORACLE_HOME=/u02/ogg19c
4 export PATH=$ORACLE_HOME/bin:$PATH
5 export LD_LIBRARY_PATH=$ORACLE_HOME/lib
[root@localhost ~]# # delete line number ---> 3 and 5 using below
[root@localhost ~]# sed -i '3,5d' bash_profile
[root@localhost ~]#
[root@localhost ~]# cat -n bash_profile
1 india
2 is my country
