CSH/TCSH

Foreach is csh built-in command for control flow,below is some examples 

[j@localhost ~]$ foreach x (a b c 1 2 3)
foreach? echo $x
foreach? end
a
b
c
1
2
3

OR iterate from file

[j@localhost ~]$ foreach x ( `cat file.txt ` )
foreach? echo "Here is the $x"
foreach? end
Here is the 1stline
Here is the 2ndline
Here is the 3rdline
[j@localhost ~]$

BASH

In bash there is no foreach , so we can use “for” instead

[j@localhost ~]$ for x in a b c 1 2 3;do echo $x;done
a
b
c
1
2
3

Or if need to iterate from a file

[j@localhost ~]$ for x in `cat file.txt`;do echo "Here is $x";done
Here is 1stline
Here is 2ndline
Here is 3rdline

Or we can also use “while” to iterate from file

[j@localhost ~]$ while read file
> do
> echo "Here is $file"
> done < file.txt
Here is 1stline
Here is 2ndline
Here is 3rdline
[j@localhost ~]$