bash: start multiple chained commands in background

Question

I\'m trying to run some commands in paralel, in background, using bash. Here\'s what I\'m trying to do:

forloop {
  //this part is actually written in perl
          


        

Answer 1

Another way is to use the following syntax:

{ command1; command2; command3; } &
wait

Note that the & goes at the end of the command group, not after each command. The semicolon after the final command is necessary, as are the space after the first bracket and before the final bracket. The wait at the end ensures that the parent process is not killed before the spawned child process (the command group) ends.

You can also do fancy stuff like redirecting stderr and stdout:

{ command1; command2; command3; } 2>&2 1>&1 &

Your example would look like:

forloop() {
    { touch .file1.lock; cp bigfile1 /destination; rm .file1.lock; } &
}
# ... do some other concurrent stuff
wait # wait for childs to end