For loops in bash

With an interval

for i in {1..10};
do
    echo "line $i"
done

Loop through filenames:

for file in *.json; do
ls -l $file
done

Loop using the output of a subcommand:

for file in $(find . -name '*.json'); do
ls -l $file
done

Single liner: for i in {1..5}; do echo $i; done