how.wtf

For Loops in Bash

· Thomas Taylor

Using a for loop in Bash is simple!

for loop over strings

1for i in "follow" "the" "white" "rabbit"; do
2    echo "${i}"
3done
1follow
2the
3white
4rabbit

for loop with range

1for i in {0..2}; do
2    echo "${i}"
3done
10
21
32

bash 4 added an increment parameter for ranges

1for i in {0..6..2}; do
2    echo "${i}"
3done
10
22
34
46

for loop with array

1a=("fried" "green" "tomatoes")
2for i in ${a[@]}; do
3    echo "${i}"
4done
1fried
2green
3tomatoes

for loop C-style

1for (( i = 0; i <= 3; i++ )); do
2    echo "${i}"
3done
10
21
32
43

for loop control statements: break & continue

break statement

The break statement terminates the current loop.

1for i in "first" "second" "break" "third"; do
2    if [[ "${i}" == "break" ]]; then
3        break
4    fi
5    echo "${i}"
6done
1first
2second

continue statement

The continue statement skips the current iteration and ‘continues’ to the next iteration.

1for i in "first" "second" "break" "third"; do
2    if [[ "${i}" == "break" ]]; then
3        continue
4    fi
5    echo "${i}"
6done
1first
2second
3third

#Bash  

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