Difference between revisions of "Bash loops"

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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 cmd2 $x ; done < <(cmd1)
 
  # while read x ; do cmd $x ; done < file.txt
 
  # 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