Difference between revisions of "Bash loops"
From Tech-Wiki
| (3 intermediate revisions by the same user not shown) | |||
| Line 8: | Line 8: | ||
Executing something based on command's output | Executing something based on command's output | ||
# for x in $(cmd1) ; do cmd2 $x ; done | # for x in $(cmd1) ; do cmd2 $x ; done | ||
| + | # while read x ; do cmd2 $x ; done < <(cmd1) | ||
| + | # while read x ; do cmd $x ; done < file.txt | ||
Executing the same command forever | Executing the same command forever | ||
# while true; do date +%s; done | # while true; do date +%s; done | ||
Latest revision as of 23:10, 26 June 2021
Executing a Do loop to repeat one command with different hosts
# for num in {1..5}; do ssh host-$num "shutdown"; done
# for host in `cat hosts.txt`; do ssh $host "shutdown"; done
# while read LINE; do COMMAND $LINE; done < FILE
Executing something based on command's output
# for x in $(cmd1) ; do cmd2 $x ; done # while read x ; do cmd2 $x ; done < <(cmd1) # while read x ; do cmd $x ; done < file.txt
Executing the same command forever
# while true; do date +%s; done