ole-tange

#!/bin/bash

# Show that mixing of output can occur with 'echo' with less than 4 KB argument

echo testing echo - any output indicates that mixing has taken place.
# Generate 20000 lines with: echo aa...a &
#                            echo bb...b &
# where aa...a = 4000 a's, and bb...b = 4000 b's.
perl -e '$a="a"x4000; $b="b"x4000; for(1..10000) { print "echo $a &\n echo $b &\n" }' |
  # Execute them. Because of '&' the commands will run in parallel

ole-tange

#!/bin/bash                                                                                                                                       

open_dns() {
    # Look for open DNS at X.X.Y.Y                                                                                                                
    parallel -j0 --tag host -t a youtube.com {1}.{1}.{2}.{2} ::: {1..255} ::: {1..255} |
        grep 'youtube.com has address' |
        perl -pe 's/^(\d+) (\d+)\t.*/$1.$1.$2.$2/'
}

if [ ! -e open_dns_list ] ; then

ole-tange

first
second
third
fourth
fifth
sixth
seventh
eighth
ninth
tenth

ole-tange

abildstrup adolphines bartholine brunhildes bulgariens christabel
columbines galionsvej hieronymus hildeborgs kalundborg leonhardts
limfjorden lunderskov mickeysoft reinholdts rejnholdts tulipanvej
uzbekistan adjunkters adoptering adverbiums afblomstre afguderisk
afhjemling afkoblings afmeldings afskyeligt afspejling aftensbord
afveksling agentfilms agnostiker agurketids akronymets albuminers
albuminets algoritmen algoritmes alkymisten alkymister almengjort
altmodisch altruismen amnestilov amplituden amplituder amplitudes
amputering andetsprog angerfuldt anisbolche anskueligt antilopers
antipoders arbejdsfil arbejdsliv arbejdsomt arbejdstog armbindets

ole-tange

    $ cat ls-dev-disk-by-uuid 
    lrwxrwxrwx 1 root root 10 Apr 27 01:13 /dev/disk/by-uuid/09ecdc0d-0d37-4e21-b771-6176b30ae002 -> ../../sda5
    lrwxrwxrwx 1 root root 10 Apr 27 01:13 /dev/disk/by-uuid/9ff8d3c8-e58a-4ba1-b8b3-f6a58e2c04a9 -> ../../dm-6
    lrwxrwxrwx 1 root root 10 Apr 27 01:13 /dev/disk/by-uuid/cf998061-fa83-4c11-94ae-ca1b9b955180 -> ../../sda1
    lrwxrwxrwx 1 root root  9 Apr 27 01:13 /dev/disk/by-uuid/d6e16359-2a8a-4fe7-9523-f6864aa7555e -> ../../sdb
    lrwxrwxrwx 1 root root 10 Apr 27 01:13 /dev/disk/by-uuid/ef010918-29a9-4bd0-aee5-6dd621ec5d84 -> ../../dm-1
    lrwxrwxrwx 1 root root 10 Apr 27 01:15 /dev/disk/by-uuid/FD48-E073 -> ../../sdc1

    $ cat journalctl-xb 
    -- Logs begin at Thu 2017-04-27 01:09:36 CEST, end at Thu 2017-04-27 01:11:52 CEST. --

ole-tange

1359540606.28613. OpenSSH_6.0p1 Debian-3ubuntu1, OpenSSL 1.0.1c 10 May 2012
1359540606.28622. debug1: Reading configuration data /home/tange/.ssh/config
1359540606.28624. debug1: /home/tange/.ssh/config line 1: Applying options for *
1359540606.28625. debug1: /home/tange/.ssh/config line 19: Applying options for newton
1359540606.28627. debug1: Reading configuration data /etc/ssh/ssh_config
1359540606.28628. debug1: /etc/ssh/ssh_config line 19: Applying options for *
1359540606.28629. debug2: ssh_connect: needpriv 0
1359540606.28631. debug1: Connecting to newton.binf.ku.dk [130.225.211.96] port 24222.
1359540606.28632. debug1: Connection established.
1359540606.28633. debug1: identity file /home/tange/.ssh/id_rsa type 1

ole-tange

This works:

ssh linux.p  'eval `echo $SHELL | grep "/t\{0,1\}csh" > /dev/null  && echo setenv PARALLEL_SEQ '$PARALLEL_SEQ'\;  setenv PARALLEL_PID '$PARALLEL_PID'  || echo PARALLEL_SEQ='$PARALLEL_SEQ'\;export PARALLEL_SEQ\;  PARALLEL_PID='$PARALLEL_PID'\;export PARALLEL_PID` ;'  tty\ \>/dev/null\ \&\&\ stty\ isig\ -onlcr\ -echo\;perl\ -e\ \'\ use\ IO::Poll\;\ \$SIG\{CHLD\}\ =\ sub\ \{\$done\ =\ 1\}\;\ \$p\ =\ IO::Poll-\>new\;\ \$p-\>mask\(STDOUT,\ POLLHUP\)\;\ \$pid=fork\;\ unless\(\$pid\)\ \{setpgrp\;\ exec\ \$ENV\{SHELL\},\ \"-c\",\ @ARGV\;\ die\ \"exec:\ \$\!\\n\"\}\ \$p-\>poll\;\ kill\ SIGHUP,\ -\$pid\ unless\ \$done\;\ wait\;\ exit\ \(\$\?\&127\ \?\ 128+\(\$\?\&127\)\ :\ 1+\$\?\>\>8\)\ \'\ echo\\\ OK\\\;ls\\\ output_to_STDERR\\\ ;

This blocks (does not finish):

ssh solaris.p  'eval `echo $SHELL | grep "/t\{0,1\}csh" > /dev/null  && echo setenv PARALLEL_SEQ '$PARALLEL_SEQ'\;  setenv PARALLEL_PID '$PARALLEL_PID'  || echo PARALLEL_SEQ='$PARALLEL_SEQ'\;export PARALLEL_SEQ\;  PARALLEL_PID='$PARALLEL_PID'\;e