While
Counting to 3 and doing something along the way right on the command line.
# i=1; while [ "$i" -lt 4 ]; do echo $i; i=$(($i+1)); done
1
2
3
The same command in a script:
#!/bin/bash
i=0
while [ "$i" -lt 10 ]
do
echo $i
i=$(($i+1))
done
For
Iterate through lines in a file with a for loop on the command line.
# for a in $(cat /tmp/users); do echo $a; done
usera
userb
In a script:
#!/bin/bash
for a in $(cat /tmp/users)
do
