niceload: multiple -p

src/niceload

@@ -40,6 +40,7 @@ if($opt::factor and $opt::suspend) {
     help();
     exit;
 }
+
 if(not (defined $opt::start_io or defined $opt::run_io
 	or defined $opt::start_load or defined $opt::run_load
 	or defined $opt::start_mem or defined $opt::run_mem
@@ -63,8 +64,9 @@ if(defined $opt::load) { multiply_binary_prefix($opt::load); }
 
 my $limit = Limit->new();
 my $process = Process->new($opt::nice,@ARGV);
-if($opt::pid) {
-    $process->set_pid($opt::pid);
+$::exitstatus = 0;
+if(@opt::pid) {
+    $process->set_pid(@opt::pid);
 } elsif (@ARGV) {
     # Wait until limit is below start_limit and run_limit
     while($limit->over_start_limit()
@@ -91,6 +93,11 @@ while($process->is_alive()) {
 
 exit($::exitstatus);
 
+sub uniq {
+    # Remove duplicates and return unique values
+    return keys %{{ map { $_ => 1 } @_ }};
+}
+
 sub multiply_binary_prefix {
     # Evalualte numbers with binary prefix
     # k=10^3, m=10^6, g=10^9, t=10^12, p=10^15, e=10^18, z=10^21, y=10^24
@@ -291,10 +298,22 @@ sub new {
     }, ref($class) || $class;
 }
 
+sub pgrp {
+    my $self = shift;
+    my @pgrp;
+    if(not $self->{'pgrp'}) {
+	for(@{$self->{'pids'}}) {
+	    push @pgrp,-getpgrp($_);
+	}
+	@pgrp = uniq(@pgrp);
+	@{$self->{'pgrp'}} = @pgrp;
+    }
+    return @{$self->{'pgrp'}};
+}
+
 sub set_pid {
     my $self = shift;
-    $self->{'pid'} = shift;
-    push(@{$self->{'pids'}},$self->{'pid'});
+    push(@{$self->{'pids'}},@_);
     $self->{'running'} = 1;
     $::exitstatus = 0;
 }
@@ -313,7 +332,6 @@ sub start {
 	$SIG{TSTP}=\&kill_child_TSTP;
 	$SIG{CONT}=\&kill_child_CONT;
  	sleep 1; # Give child time to setpgrp(0,0);
- 	$self->{'pgrp'} = getpgrp $self->{'pid'};
     } else {
  	setpgrp(0,0);
  	::debug("Child pid: $$, pgrp: ",getpgrp $$,"\n");
@@ -345,15 +363,15 @@ sub REAPER {
 
 sub kill_child_CONT {
     my $self = $Global::process;
-    ::debug("SIGCONT received. Killing $self->{'pid'}\n");
-    kill CONT => -getpgrp($self->{'pid'});
+    ::debug("SIGCONT received. Killing @{$self->{'pgrp'}}\n");
+    kill CONT => $self->pgrp();
 }
 
 
 sub kill_child_TSTP {
     my $self = $Global::process;
     ::debug("SIGTSTP received. Killing $self->{'pid'} and self ($$)\n");
-    kill TSTP => -getpgrp($self->{'pid'});
+    kill TSTP => $self->pgrp();
     kill STOP => -$$;
     kill STOP => $$;
 }
@@ -362,7 +380,7 @@ sub kill_child_TSTP {
 sub kill_child_INT {
     my $self = $Global::process;
     ::debug("SIGINT received. Killing $self->{'pid'} Exit\n");
-    kill INT => -getpgrp($self->{'pid'});
+    kill INT => $self->pgrp();
     exit;
 }
 

src/parallel.texi

@@ -1965,6 +1965,10 @@ can be written like this:
 
 @strong{cat list | parallel do_something | process_output}
 
+For example: Find which host name in a list has IP address 1.2.3 4:
+
+@strong{cat hosts.txt | parallel -P 100 host | grep 1.2.3.4}
+
 If the processing requires more steps the for-loop like this:
 
 @verbatim
@@ -2194,14 +2198,6 @@ GNU @strong{parallel} can often speed this up.
 
 This will run 1.5 job per core, and give 1000 arguments to @strong{grep}.
 
-To grep a big file in parallel use @strong{--pipe}:
-
-@strong{cat bigfile | parallel --pipe grep foo}
-
-Depending on your disks and CPUs it may be faster to read larger blocks:
-
-@strong{cat bigfile | parallel --pipe --block 10M grep foo}
-
 @chapter EXAMPLE: Using remote computers
 @anchor{EXAMPLE: Using remote computers}
 

testsuite/tests-to-run/niceload03.sh

@@ -7,5 +7,7 @@ cat <<'EOF' | stdout parallel -j0 -L1
 echo '### --soft -f and test if child is actually suspended and thus takes longer'
   niceload --soft -t 0.2 -f 0.5 'seq 1000000 | wc;echo This should finish last'
   (sleep 1; seq 1000000 | wc;echo This should finish first)
+echo '### niceload with no arguments should give no output'
+  niceload
 EOF
 

testsuite/tests-to-run/niceload04.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+# force load > 10
+while uptime | grep -v age:.[1-9][0-9].[0-9][0-9] >/dev/null ; do (timeout 5 nice burnP6 2>/dev/null &) done
+
+sleep 1 &
+PID1=$!
+sleep 1 &
+PID2=$!
+sleep 1 &
+PID3=$!
+stdout /usr/bin/time -f %e niceload -l 8 -H -p $PID1 -p $PID2 -p $PID3 | perl -ne '$_ >= 5 and print "OK\n"'

testsuite/wanted-results/niceload03

@@ -1,4 +1,5 @@
 ### --soft -f and test if child is actually suspended and thus takes longer
+### niceload with no arguments should give no output
 1000000 1000000 6888896
 This should finish first
 1000000 1000000 6888896

testsuite/wanted-results/niceload04

@@ -0,0 +1 @@
+OK