Difference between revisions of "Bash loops"
From Tech-Wiki
| (6 intermediate revisions by the same user not shown) | |||
| Line 2: | Line 2: | ||
Executing a Do loop to repeat one command with different hosts | Executing a Do loop to repeat one command with different hosts | ||
| − | # for | + | # 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 $x ; done < file.txt | ||
Executing the same command forever | Executing the same command forever | ||
# while true; do date +%s; done | # while true; do date +%s; done | ||
Latest revision as of 22:10, 26 June 2021
Executing a Do loop to repeat one command with different hosts
# for num in {1..5}; do ssh host-$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