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Looping with For and While

Problem

You want to loop a number of times in UNIX.

Problem	Solution	Example	Reference	Recommended
For example, spin around 100 times and print hello: i=0; while [[ $i -lt 100 ]] ; do echo -n 'hello'; ((i++)) ; done; echo '' hellohellohellohellohellohellohellohellohellohello hellohellohellohellohellohellohellohellohellohello hellohellohellohellohellohellohellohellohellohello hellohellohellohellohellohellohellohello… Similarily the for command is a beauty too, spin around 5 times and kick off a loop 5 times - paste the result into 5 columns: for i in 1 2 3 4 5; do for j in 1 2 3 4 5; do echo "$i:$j"; done; done \| paste - - - - - 1:1 1:2 1:3 1:4 1:5 2:1 2:2 2:3 2:4 2:5 3:1 3:2 3:3 3:4 3:5 4:1 4:2 4:3 4:4 4:5 5:1 5:2 5:3 5:4 5:5

Looping with For and While

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