tethereal -i eth0 -w mycapture.pcap
sending SIGTERM or SIGINT (ctrl-c) will cause it to exit cleanly.
wireshark command line capture
sending SIGTERM or SIGINT (ctrl-c) will cause it to exit cleanly.
Serial Port in Linux
stty
stty -F /dev/ttyS10 stty -F /dev/ttyS10 -a stty -F /dev/ttyS10 230400 crtscts stty -F /dev/ttyS10 230400 -crtsctshttp://www.armadeus.com/wiki/index.php?title=Serial_ports_usage_on_Linux
minicom
minicom -s minicom ttys10 (ttys10 is a saved config) ctrl-a q (quit) ctrl-a o (config) ctrl-z (help)
screen
screen /dev/ttyS10 115200
screen /dev/ttyS10 115200,crtscts
ctrl-a K (kill)
ctrl-a d (detach)
ctrl-a i (status)
$ sudo screen -ls
There are screens on:
7578.pts-0.fedora (Detached)
7575.pts-0.fedora (Detached)
2009.pts-0.fedora (Detached)
$ sudo screen -r 7578 -X kill
$ sudo screen -r 7575 -X kill
$ sudo screen -r 2009 -X kill
$ sudo screen -ls
# copy and paste
C-a : bufferfile /etc/passwd
C-a < C-a ]
C-a : bufferfile
No Sockets found in /var/run/screen/S-root.
MFC 495CW Printer Setup on Fedora 17
Download and install the following:
mfc495cwlpr-1.1.2-1.i386.rpm mfc495cwcupswrapper-1.1.2-2.i386.rpmThen copy the file brlpdwrappermfc495cw to /usr/lib/cups/filter/. Don't remember where it comes but had a copy from my old machine:
$ cat packages/brother/brlpdwrappermfc495cw
#! /bin/sh
#
# Copyright (C) 2005 Brother. Industries, Ltd.
# Ver1.10
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 2 of the License, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 59 Temple
# Place, Suite 330, Boston, MA 02111-1307 USA
#
LOGFILE="/dev/null"
LOGLEVEL="1"
LOGCLEVEL="7"
DEBUG=0
NUPENABLE=1
LOG_LATESTONLY=1
errorcode=0
if [ $DEBUG != 0 ]; then
LOGFILE=/tmp/br_cupsfilter_debug_log
fi
PPDC=`printenv | grep "PPD="`
PPDC=`echo $PPDC | sed -e 's/PPD=//'`
if [ "$PPDC" = "" ]; then
PPDC="/usr/share/cups/model/brmfc495cw.ppd"
fi
if [ $LOGFILE != "/dev/null" ]; then
if [ $LOG_LATESTONLY == "1" ]; then
rm -f $LOGFILE
date >$LOGFILE
else
if [ -e $LOGFILE ]; then
date >>$LOGFILE
else
date >$LOGFILE
fi
fi
echo "arg0 = $0" >>$LOGFILE
echo "arg1 = $1" >>$LOGFILE
echo "arg2 = $2" >>$LOGFILE
echo "arg3 = $3" >>$LOGFILE
echo "arg4 = $4" >>$LOGFILE
echo "arg5 = $5" >>$LOGFILE
echo "arg6 = $6" >>$LOGFILE
echo "PPD = $PPD" >>$LOGFILE
fi
INPUT_TEMP_PS=`mktemp /tmp/br_input_ps.XXXXXX`
nup="cat"
if [ "" != '' ] && [ $NUPENABLE != 0 ]; then
if [ "" != '' ]; then
nup="psnup -64"
elif [ "" != '' ]; then
nup="psnup -32"
elif [ "" != '' ]; then
nup="psnup -25"
elif [ "" != '' ]; then
nup="psnup -16"
elif [ "" != '' ]; then
nup="psnup -8"
elif [ "" != '' ]; then
nup="psnup -6"
elif [ "" != '' ]; then
nup="psnup -4"
elif [ "" != '' ]; then
nup="psnup -2"
elif [ "" != '' ]; then
nup="cat"
fi
echo "NUP=$nup" >>$LOGFILE
if [ -e /usr/bin/psnup ]; then
if [ $# -ge 7 ]; then
cat $6 | $nup > $INPUT_TEMP_PS
else
cat | $nup > $INPUT_TEMP_PS
fi
else
if [ $# -ge 7 ]; then
cp $6 $INPUT_TEMP_PS
else
cat > $INPUT_TEMP_PS
fi
fi
else
if [ $# -ge 7 ]; then
cp $6 $INPUT_TEMP_PS
else
cat > $INPUT_TEMP_PS
fi
fi
if [ -e "/usr/local/Brother/Printer/mfc495cw/lpd/filtermfc495cw" ]; then
:
else
echo "ERROR: /usr/local/Brother/Printer/mfc495cw/lpd/filtermfc495cw does not exist" >>$LOGFILE
errorcode=30
exit
fi
CUPSOPTION=`echo "$5 Copies=$4" | sed -e 's/BrMirror=OFF/MirrorPrint=OFF/' -e 's/BrMirror=ON/MirrorPrint=ON/' -e 's/BrChain/Chain/' -e 's/BrBrightness/Brightness/' -e 's/BrContrast/Contrast/' -e 's/BrHalfCut/HalfCut/' -e 's/BrAutoTapeCut/AutoCut/' -e 's/BrHalftonePattern/Halftone/' -e 's/Binary/Binary/' -e 's/Dither/Dither/' -e 's/ErrorDiffusion/ErrorDiffusion/' -e 's/PageSize/media/' -e 's/BrSheets/Sheets/' -e 's/multiple-document-handling/Collate/' -e 's/separate-documents-collated-copies/ON/' -e 's/separate-documents-uncollated-copies/OFF/'`
if [ -e "/usr/local/Brother/Printer/mfc495cw/cupswrapper/brcupsconfpt1" ]; then
if [ $DEBUG = 0 ]; then
/usr/local/Brother/Printer/mfc495cw/cupswrapper/brcupsconfpt1 MFC495CW $PPDC 0 "$CUPSOPTION" "mfc495cw">> /dev/null
else
/usr/local/Brother/Printer/mfc495cw/cupswrapper/brcupsconfpt1 MFC495CW $PPDC $LOGCLEVEL "$CUPSOPTION" "mfc495cw">>$LOGFILE
fi
fi
if [ $DEBUG -lt 10 ]; then
cat $INPUT_TEMP_PS | /usr/local/Brother/Printer/mfc495cw/lpd/filtermfc495cw "$$" "CUPS" "USB"
if [ $LOGLEVEL -gt 2 ]; then
if [ $LOGFILE != "/dev/null" ]; then
echo "" >>$LOGFILE
echo " ------PostScript Data-------" >>$LOGFILE
cat $INPUT_TEMP_PS >>$LOGFILE
fi
fi
fi
rm -f $INPUT_TEMP_PS
exit
also see http://en.gentoo-wiki.com/wiki/Brother_Mfc-495cw
udevadm
$ udevadm info -q path -n /dev/sdc
/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10/target10:0:0/10:0:0:0/block/sdc
[jshih@i7 ~]$ udevadm info -a -p $(udevadm info -q path -n /dev/sdc)
Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.
looking at device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10/target10:0:0/10:0:0:0/block/sdc':
KERNEL=="sdc"
SUBSYSTEM=="block"
DRIVER==""
ATTR{ro}=="0"
ATTR{size}=="976773168"
ATTR{stat}==" 1172 43 9062 4975 0 0 0 0 0 1307 4974"
ATTR{range}=="16"
ATTR{discard_alignment}=="0"
ATTR{events}==""
ATTR{ext_range}=="256"
ATTR{events_poll_msecs}=="-1"
ATTR{alignment_offset}=="0"
ATTR{inflight}==" 0 0"
ATTR{removable}=="0"
ATTR{capability}=="50"
ATTR{events_async}==""
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10/target10:0:0/10:0:0:0':
KERNELS=="10:0:0:0"
SUBSYSTEMS=="scsi"
DRIVERS=="sd"
ATTRS{rev}=="0001"
ATTRS{type}=="0"
ATTRS{scsi_level}=="0"
ATTRS{model}=="3AS "
ATTRS{state}=="running"
ATTRS{queue_type}=="none"
ATTRS{iodone_cnt}=="0x4eb"
ATTRS{iorequest_cnt}=="0x4eb"
ATTRS{timeout}=="30"
ATTRS{evt_media_change}=="0"
ATTRS{max_sectors}=="240"
ATTRS{ioerr_cnt}=="0x7"
ATTRS{queue_depth}=="1"
ATTRS{vendor}=="ST950042"
ATTRS{device_blocked}=="0"
ATTRS{dh_state}=="detached"
ATTRS{iocounterbits}=="32"
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10/target10:0:0':
KERNELS=="target10:0:0"
SUBSYSTEMS=="scsi"
DRIVERS==""
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10':
KERNELS=="host10"
SUBSYSTEMS=="scsi"
DRIVERS==""
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0':
KERNELS=="4-2:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="usb-storage"
ATTRS{bInterfaceClass}=="08"
ATTRS{bInterfaceSubClass}=="06"
ATTRS{bInterfaceProtocol}=="50"
ATTRS{bNumEndpoints}=="02"
ATTRS{supports_autosuspend}=="1"
ATTRS{bAlternateSetting}==" 0"
ATTRS{bInterfaceNumber}=="00"
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2':
KERNELS=="4-2"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{devpath}=="2"
ATTRS{idVendor}=="174c"
ATTRS{speed}=="5000"
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bMaxPacketSize0}=="9"
ATTRS{busnum}=="4"
ATTRS{devnum}=="2"
ATTRS{configuration}==""
ATTRS{bMaxPower}==" 0mA"
ATTRS{authorized}=="1"
ATTRS{bmAttributes}=="c0"
ATTRS{bNumConfigurations}=="1"
ATTRS{maxchild}=="0"
ATTRS{bcdDevice}=="0100"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{quirks}=="0x0"
ATTRS{serial}=="0123456789ABCDEF"
ATTRS{version}==" 3.00"
ATTRS{urbnum}=="3770"
ATTRS{ltm_capable}=="no"
ATTRS{manufacturer}=="ASMedia"
ATTRS{removable}=="unknown"
ATTRS{idProduct}=="55aa"
ATTRS{bDeviceClass}=="00"
ATTRS{product}=="AS2105"
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4':
KERNELS=="usb4"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="03"
ATTRS{devpath}=="0"
ATTRS{idVendor}=="1d6b"
ATTRS{speed}=="5000"
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bMaxPacketSize0}=="9"
ATTRS{authorized_default}=="1"
ATTRS{busnum}=="4"
ATTRS{devnum}=="1"
ATTRS{configuration}==""
ATTRS{bMaxPower}==" 0mA"
ATTRS{authorized}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bNumConfigurations}=="1"
ATTRS{maxchild}=="2"
ATTRS{bcdDevice}=="0306"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{quirks}=="0x0"
ATTRS{serial}=="0000:04:00.0"
ATTRS{version}==" 3.00"
ATTRS{urbnum}=="96"
ATTRS{ltm_capable}=="no"
ATTRS{manufacturer}=="Linux 3.6.7-4.fc17.x86_64 xhci_hcd"
ATTRS{removable}=="unknown"
ATTRS{idProduct}=="0003"
ATTRS{bDeviceClass}=="09"
ATTRS{product}=="xHCI Host Controller"
looking at parent device '/devices/pci0000:00/0000:00:1c.4/0000:04:00.0':
KERNELS=="0000:04:00.0"
SUBSYSTEMS=="pci"
DRIVERS=="xhci_hcd"
ATTRS{irq}=="42"
ATTRS{subsystem_vendor}=="0x1458"
ATTRS{broken_parity_status}=="0"
ATTRS{class}=="0x0c0330"
ATTRS{consistent_dma_mask_bits}=="32"
ATTRS{dma_mask_bits}=="64"
ATTRS{local_cpus}=="00000000,00000000,00000000,000000ff"
ATTRS{device}=="0x7023"
ATTRS{msi_bus}==""
ATTRS{local_cpulist}=="0-7"
ATTRS{vendor}=="0x1b6f"
ATTRS{subsystem_device}=="0x5007"
ATTRS{numa_node}=="-1"
ATTRS{d3cold_allowed}=="1"
looking at parent device '/devices/pci0000:00/0000:00:1c.4':
KERNELS=="0000:00:1c.4"
SUBSYSTEMS=="pci"
DRIVERS=="pcieport"
ATTRS{irq}=="16"
ATTRS{subsystem_vendor}=="0x1458"
ATTRS{broken_parity_status}=="0"
ATTRS{class}=="0x060400"
ATTRS{consistent_dma_mask_bits}=="32"
ATTRS{dma_mask_bits}=="32"
ATTRS{local_cpus}=="00000000,00000000,00000000,000000ff"
ATTRS{device}=="0x1c18"
ATTRS{msi_bus}=="1"
ATTRS{local_cpulist}=="0-7"
ATTRS{vendor}=="0x8086"
ATTRS{subsystem_device}=="0x5001"
ATTRS{numa_node}=="-1"
ATTRS{d3cold_allowed}=="0"
looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""
[jshih@i7 ~]$ udevadm info -q path -n /dev/sdc
/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10/target10:0:0/10:0:0:0/block/sdc
[jshih@i7 ~]$ udevadm info -q env -n /dev/sdc
DEVLINKS=/dev/disk/by-id/ata-ST9500423AS_6WR0N60Q /dev/disk/by-id/wwn-0x5000c5004a982eb5 /dev/disk/by-path/pci-0000:04:00.0-usb-0:2:1.0-scsi-0:0:0:0
DEVNAME=/dev/sdc
DEVPATH=/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/usb4/4-2/4-2:1.0/host10/target10:0:0/10:0:0:0/block/sdc
DEVTYPE=disk
ID_ATA=1
ID_ATA_DOWNLOAD_MICROCODE=1
ID_ATA_FEATURE_SET_APM=1
ID_ATA_FEATURE_SET_APM_CURRENT_VALUE=128
ID_ATA_FEATURE_SET_APM_ENABLED=1
ID_ATA_FEATURE_SET_HPA=1
ID_ATA_FEATURE_SET_HPA_ENABLED=1
ID_ATA_FEATURE_SET_PM=1
ID_ATA_FEATURE_SET_PM_ENABLED=1
ID_ATA_FEATURE_SET_SECURITY=1
ID_ATA_FEATURE_SET_SECURITY_ENABLED=0
ID_ATA_FEATURE_SET_SECURITY_ENHANCED_ERASE_UNIT_MIN=96
ID_ATA_FEATURE_SET_SECURITY_ERASE_UNIT_MIN=96
ID_ATA_FEATURE_SET_SMART=1
ID_ATA_FEATURE_SET_SMART_ENABLED=1
ID_ATA_ROTATION_RATE_RPM=7200
ID_ATA_SATA=1
ID_ATA_SATA_SIGNAL_RATE_GEN1=1
ID_ATA_SATA_SIGNAL_RATE_GEN2=1
ID_ATA_WRITE_CACHE=1
ID_ATA_WRITE_CACHE_ENABLED=1
ID_BUS=ata
ID_MODEL=ST9500423AS
ID_MODEL_ENC=ST9500423AS\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20
ID_PART_TABLE_TYPE=dos
ID_PATH=pci-0000:04:00.0-usb-0:2:1.0-scsi-0:0:0:0
ID_PATH_TAG=pci-0000_04_00_0-usb-0_2_1_0-scsi-0_0_0_0
ID_REVISION=0001SD5M
ID_SERIAL=ST9500423AS_6WR0N60Q
ID_SERIAL_SHORT=6WR0N60Q
ID_TYPE=disk
ID_WWN=0x5000c5004a982eb5
ID_WWN_WITH_EXTENSION=0x5000c5004a982eb5
MAJOR=8
MINOR=32
SUBSYSTEM=block
TAGS=:systemd:
UDISKS_ATA_SMART_IS_AVAILABLE=1
UDISKS_PARTITION_TABLE=1
UDISKS_PARTITION_TABLE_COUNT=12
UDISKS_PARTITION_TABLE_SCHEME=mbr
UDISKS_PRESENTATION_NOPOLICY=0
USEC_INITIALIZED=966774215
Create Fedora Installation USB with Live USB Creator
Download the Fedora-DVD.iso and install liveusb-creator.noarch. Start the Live USB Creator and browse the iso file.
i7 2600k temperature @ 3.7Ghz on F17
On Fedora 17.
idle
[root@i7 ~]# cat /proc/cpuinfo |grep MH cpu MHz : 1600.000 cpu MHz : 1600.000 cpu MHz : 1600.000 cpu MHz : 1600.000 cpu MHz : 1600.000 cpu MHz : 1600.000 cpu MHz : 1600.000 cpu MHz : 1600.000 [root@i7 ~]# sensors coretemp-isa-0000 Adapter: ISA adapter Physical id 0: +34.0°C (high = +80.0°C, crit = +98.0°C) Core 0: +27.0°C (high = +80.0°C, crit = +98.0°C) Core 1: +31.0°C (high = +80.0°C, crit = +98.0°C) Core 2: +34.0°C (high = +80.0°C, crit = +98.0°C) Core 3: +30.0°C (high = +80.0°C, crit = +98.0°C)
fully loaded
$ cat /proc/cpuinfo |grep MH cpu MHz : 3701.000 cpu MHz : 3701.000 cpu MHz : 3701.000 cpu MHz : 3701.000 cpu MHz : 3701.000 cpu MHz : 3701.000 cpu MHz : 3701.000 cpu MHz : 3701.000 $ sensors coretemp-isa-0000 Adapter: ISA adapter Physical id 0: +60.0°C (high = +80.0°C, crit = +98.0°C) Core 0: +56.0°C (high = +80.0°C, crit = +98.0°C) Core 1: +56.0°C (high = +80.0°C, crit = +98.0°C) Core 2: +61.0°C (high = +80.0°C, crit = +98.0°C) Core 3: +56.0°C (high = +80.0°C, crit = +98.0°C)
Protobuf Examples C++ and Java (2)
This sample .proto is taken from http://www.indelible.org/ink/protobuf-polymorphism/.
Also see example 1
animal.proto
package animal;
option java_outer_classname = "Animals";
message Cat
{
optional bool declawed = 1;
}
message Dog
{
optional uint32 bones_buried = 1;
}
message Animal
{
required float weight = 1;
optional Dog dog = 2;
optional Cat cat = 3;
}
animal.cpp
#include#include "animal.pb.h" using namespace std; using namespace animal; int main() { Cat cat1; cat1.set_declawed(true); Animal animal; animal.set_weight(10.4); Cat* cat = animal.mutable_cat(); cat->set_declawed(true); Dog *dog = animal.mutable_dog(); dog->set_bones_buried (32); string s; animal.SerializeToString(&s); Animal animal2; animal2.ParseFromString(s); printf("weight %f\n", animal2.weight()); if (animal.has_cat()) { printf("cat %d\n", animal.cat().declawed()); } if (animal.has_dog()) { printf("dog %d\n", animal.dog().bones_buried()); } return 0; }
animal.java
import animal.Animals;
import com.google.protobuf.GeneratedMessage;
import com.google.protobuf.ExtensionRegistry;
import com.google.protobuf.*;
import java.io.IOException;
class AnimalExample {
public static void main(String[] args) throws Exception {
Animals.Animal animal = Animals.Animal.newBuilder().
setWeight(10.4F)
.setDog(Animals.Dog.newBuilder().setBonesBuried(32).build())
.setCat(Animals.Cat.newBuilder().setDeclawed(true).build())
.build();
byte[] data = animal.toByteArray();
Animals.Animal animal2 = Animals.Animal.newBuilder().mergeFrom(data).build();
System.out.println("Animal weight " + animal2.getWeight());
if (animal2.hasCat()) {
System.out.println("Cat " + animal2.getCat().getDeclawed());
}
if (animal2.hasDog()){
System.out.println("Dog " + animal2.getDog().getBonesBuried());
}
}
}
Protobuf Examples for C++ and Java (1)
This sample .proto is taken from http://blog.wolfman.com/articles/2011/11/23/how-to-implement-polymorphic-protocol-buffers-in-java. The groovy is rewritten in Java and C++. Also see example 2
example.proto
package example;
option java_outer_classname = "Commands";
message BaseCommand {
extensions 100 to max;
enum CommandType {
VERSION = 1;
LOGIN = 2;
}
required CommandType type = 1;
}
message Version {
extend BaseCommand {
required Version cmd = 100;
}
required fixed32 protocol = 1;
required fixed32 versions = 2;
}
message Login {
extend BaseCommand {
required Login cmd = 101;
}
required string username = 1;
required string password = 2;
}
example.cpp
#include#include "example.pb.h" using namespace std; using namespace example; int main() { string sl; BaseCommand b; #if 0 Version ver; ver.set_versions(10); ver.set_protocol(15); b.MutableExtension(Version::cmd)->set_versions(10); b.MutableExtension(Version::cmd)->set_protocol(15); b.set_type( BaseCommand::VERSION); #else b.set_type( BaseCommand::LOGIN); b.MutableExtension(Login::cmd)->set_username("rain"); b.MutableExtension(Login::cmd)->set_password("heavy"); #endif b.SerializeToString(&sl); printf("%d\n", sl.length()); BaseCommand* bcmd = new BaseCommand(); if (bcmd->ParseFromString(sl)) { printf("ParsePartialFromString ok\n"); } printf("%d\n", bcmd->type()); switch(bcmd->type()) { case BaseCommand::LOGIN: { printf("login\n"); printf("%s %s\n", b.MutableExtension(Login::cmd)->username().c_str(), b.MutableExtension(Login::cmd)->password().c_str()); break; } case BaseCommand::VERSION: { printf("version\n"); printf("%d %d\n", b.MutableExtension(Version::cmd)->versions(), b.MutableExtension(Version::cmd)->protocol()); break; } default: break; } return 1; }
example.java
import example.Commands;
import example.Commands.BaseCommand;
import com.google.protobuf.GeneratedMessage;
import com.google.protobuf.ExtensionRegistry;
import java.io.IOException;
class ProtoBufExample {
// Helper which wraps the BaseCommand around the extension command
static BaseCommand wrap(BaseCommand.CommandType type, GeneratedMessage.GeneratedExtension extension, Type cmd) {
return BaseCommand.newBuilder().setType(type).setExtension(extension, cmd).build();
}
ExtensionRegistry registry;
ProtoBufExample() {
// we need to register all the extensions and tell the decoder about them
// otherwise the extension will be ignored
registry= ExtensionRegistry.newInstance();
Commands.registerAllExtensions(registry);
}
BaseCommand buildVersion(int v1, int v2) {
Commands.Version vers= Commands.Version.newBuilder().setProtocol(v1).setVersions(v2).build();
// BaseCommand bcmd= BaseCommand.newBuilder().setType(BaseCommand.CommandType.VERSION).setExtension(Commands.Version.cmd, vers).build();
return wrap(BaseCommand.CommandType.VERSION, Commands.Version.cmd, vers);
}
BaseCommand buildLogin(String username, String password) {
Commands.Login l= Commands.Login.newBuilder().setUsername(username).setPassword(password).build();
return wrap(BaseCommand.CommandType.LOGIN, Commands.Login.cmd, l);
}
BaseCommand decodeIt(byte [] ba) {
// use the registry so extensions will be decoded
try{
BaseCommand b=BaseCommand.newBuilder().mergeFrom(ba, registry).build();
return b;
}
catch (IOException e) {
System.out.println("Unable to create " +e.getMessage());
return buildVersion(0,1);
}
}
public static void main(String[] args) throws Exception {
ProtoBufExample pb= new ProtoBufExample();
BaseCommand b= pb.buildVersion(1234, 5678);
//BaseCommand b= pb.buildLogin("user1", "test");
System.out.println(b);
System.out.println ("size: " + b.toByteArray().length);
BaseCommand decoded= pb.decodeIt(b.toByteArray());
System.out.println ("We got a "+ decoded.getType() +" message");
// We can switch on the CommandType enum and extract the specific command type (extension) we got
switch(decoded.getType()) {
case VERSION:
System.out.println (decoded.getExtension(Commands.Version.cmd));
break;
case LOGIN:
System.out.println (decoded.getExtension(Commands.Login.cmd));
break;
default:
System.out.println ("Don't know this type");
}
}
}
Using Protobuf
C++
$ SRC_DIR=`pwd` $ ../protobuf-2.4.1/src/protoc -I=$SRC_DIR --cpp_out=. $SRC_DIR/addressbook.proto $ g++ addressbook.pb.cc writeMsg.cpp -o writeMsg -I ../protobuf-2.4.1/src -L ../protobuf-2.4.1/src/.libs/ -l protobuf $ export LD_LIBRARY_PATH=../protobuf-2.4.1/src/.libs $ ./writeMsg address.txt $ g++ addressbook.pb.cc readMsg.cpp -o readMsg -I ../protobuf-2.4.1/src -L ../protobuf-2.4.1/src/.libs/ -l protobuf $ ./readMsg address.txt Person ID: 12 Name: me E-mail address: me@t.net Home phone #: 123533333 $ ls addressbook.pb.cc addressbook.proto readMsg writeMsg addressbook.pb.h address.txt readMsg.cpp writeMsg.cpp
Java
../protobuf-2.4.1/src/protoc --java_out=../protobuf-2.4.1/java/src/main/java -I ../protobuf-2.4.1/src ../protobuf-2.4.1/src/google/protobuf/descriptor.proto cd ../protobuf-2.4.1/java/src/main/java/com/google/protobuf javac * cd - export CLASSPATH=../protobuf-2.4.1/java/src/main/java:. javac com/example/tutorial/Addressbook.java javac writeMsg.java java AddPerson javac readMsg.java java ListPeople ../c++/address.txt Person ID: 12 Name: me E-mail address: me@t.net Home phone #: 123533333
rpmbuild with rpmrc
RPM_DIR=`pwd`/rpm
echo "%_topdir $RPM_DIR" > rpmmacros
echo "macrofiles: /usr/lib/rpm/macros:/usr/lib/rpm/%{_target}/macros:/usr/lib/rpm/redhat/macros:/etc/rpm/macros.*:/etc/rpm/macros:/etc/rpm/%{_target}/macros:~/.rpmmacros:rpmmacros" > rpmrc
mkdir -p $RPM_DIR/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
rpmbuild --rcfile rpmrc --rebuild some.source.rpm
rpmbuild --rcfile rpmrc --define 'dist .el5' -without java -without python \
--target=x86_64 -ba rpm/SPECS/protobuf.spec
or redefine topdir as
rpmbuild --define "_topdir /home/user/rpmdir" --define 'dist .el5' \ -without java -without python --target=x86_64 -ba rpm/SPECS/protobuf.spec
use one thread to build for easy debugging
$ cat ~/.rpmmacros %_smp_mflags -j1
RPM Spec File
Show Spec Macros
rpm --showrc
rpm --eval %{_tmppath}
rpm --eval %{_libdir}
Variables
${LINUX_VERSION} # shell environment var
%{LINUX_VERSION} # marco var
%define LINUX_VERSION ${LINUX_VERSION} # ${LINUX_VERSION} not evaluated
%define LINUX_VERSION $(echo ${LINUX_VERSION}) # evaluated ${LINUX_VERSION}= 2.6.32.1
More Macros
http://www.rpm.org/wiki/PackagerDocs/MacrosTCP Shutdown and Close
http://blog.netherlabs.nl/articles/2009/01/18/the-ultimate-so_linger-page-or-why-is-my-tcp-not-reliable
Building Kernel Modules
% sudo yum install kernel-devel % make -C /lib/modules/$(uname -r)/build/ M=$(pwd) modules % strip --strip-debug themoudule.ko % make -C /lib/modules/$(uname -r)/build/ M=$(pwd) clean
Building inside kernel tree
make SUBDIRS=drivers/acpi/ modules make SUBDIRS=drivers/acpi/ button.ko
Linux User Space i2c
http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&ved=0CGkQFjAJ&url=http%3A%2F%2Fwww.haifux.org%2Flectures%2F258%2Fgpio_spi_i2c_userspace.pdf&ei=hu8EUKyaE8TNqgHrw-CxCA&usg=AFQjCNG-QNxl7brpTBTnzO2_JckFhdlC2Q
modprobe i2c-dev
CISCO Switch Commands
Show Commands
show version show boot show running-config show ip interface show file system show ip int brief | excl unassigned dir cd
Configure IP
enable configure t interface vlan1 ip address 192.168.11.200 255.255.255.0 no shutdown
Upgrade
Method 1, copy tar file and extract tar filecopy tftp://192.168.11.1/c2960c405-universalk9-tar.150-2.SE.tar c2960c405-universalk9-tar.150-2.SE.tar verify /md5 flash:/c2960c405-universalk9-tar.150-2.SE.tar config terminal boot system flash:/c2960c405-universalk9-mz.150-2.SE/c2960c405-universalk9-mz.150-2.SE.bin
Method 2, use archive commands which works with tar archive
archive download-sw /leave-old-sw /reload tftp://192.168.11.1/c2960c405-universalk9-tar.150-2.SE.tar
Method 3, bin file upgrade
copy tftp://192.168.11.1/c3560c405ex-universalk9-mz.150-2.SE.bin c3560c405ex-universalk9-mz.150-2.SE.bin config terminal boot system flash:c3560c405ex-universalk9-mz.150-2.SE.bin
Other commands
? copy ? delete /force /recursive c2960c405-universalk9-mz.150-2.SE copy system:running-config tftp://192.168.11.1/running-config copy nvram:startup-config tftp://192.168.11.1/startup-config copy running-config startup-config show ip int brief | excl unassigned
vlan
config t interface vlan303 ip address dhcp end ##wan interface GigabitEthernet0/10 switchport access vlan 303 switchport mode access no cdp enable spanning-tree portfast spanning-tree bpdufilter enable ##lan interface GigabitEthernet 0/5 switchport access vlan 303 switchport mode access
SNMP exec and extend
# cat /etc/snmp/snmpd.conf rocommunity public exec .1.3.6.1.4.1.2021.51 ps /bin/ps exec .1.3.6.1.4.1.2021.50 shelltest /bin/sh /tmp/shtest exec .1.3.6.1.4.1.2021.52 echotest /bin/echo hello world exec echotest11 /bin/echo hello world extend .1.3.6.1.4.1.2021.56 shelltest1 /bin/sh /tmp/test # snmpwalk -v 1 -c public localhost .1.3.6.1.4.1.2021.8 UCD-SNMP-MIB::extIndex.1 = INTEGER: 1 UCD-SNMP-MIB::extNames.1 = STRING: echotest11 UCD-SNMP-MIB::extCommand.1 = STRING: /bin/echo hello world UCD-SNMP-MIB::extResult.1 = INTEGER: 0 UCD-SNMP-MIB::extOutput.1 = STRING: hello world UCD-SNMP-MIB::extErrFix.1 = INTEGER: 0 UCD-SNMP-MIB::extErrFixCmd.1 = STRING: # snmpwalk -v 1 -c public localhost .1.3.6.1.4.1.2021.52 UCD-SNMP-MIB::ucdavis.52.1.1 = INTEGER: 1 UCD-SNMP-MIB::ucdavis.52.2.1 = STRING: "echotest" UCD-SNMP-MIB::ucdavis.52.3.1 = STRING: "/bin/echo hello world" UCD-SNMP-MIB::ucdavis.52.100.1 = INTEGER: 0 UCD-SNMP-MIB::ucdavis.52.101.1 = STRING: "hello world" UCD-SNMP-MIB::ucdavis.52.102.1 = INTEGER: 0 UCD-SNMP-MIB::ucdavis.52.103.1 = "" # snmpwalk -v 1 -c public localhost .1.3.6.1.4.1.2021.50 UCD-SNMP-MIB::ucdavis.50.1.1 = INTEGER: 1 UCD-SNMP-MIB::ucdavis.50.2.1 = STRING: "shelltest" UCD-SNMP-MIB::ucdavis.50.3.1 = STRING: "/bin/sh /tmp/shtest" UCD-SNMP-MIB::ucdavis.50.100.1 = INTEGER: 127 UCD-SNMP-MIB::ucdavis.50.101.1 = STRING: "/bin/sh: /tmp/shtest: No such file or directory" UCD-SNMP-MIB::ucdavis.50.102.1 = INTEGER: 0 UCD-SNMP-MIB::ucdavis.50.103.1 = "" [root@vsp-devel ~]# snmpwalk -v 1 -c public localhost .1.3.6.1.4.1.2021.50 UCD-SNMP-MIB::ucdavis.50.1.1 = INTEGER: 1 UCD-SNMP-MIB::ucdavis.50.2.1 = STRING: "shelltest" UCD-SNMP-MIB::ucdavis.50.3.1 = STRING: "/bin/sh /tmp/shtest" UCD-SNMP-MIB::ucdavis.50.100.1 = INTEGER: 127 UCD-SNMP-MIB::ucdavis.50.101.1 = STRING: "/bin/sh: /tmp/shtest: No such file or directory" UCD-SNMP-MIB::ucdavis.50.102.1 = INTEGER: 0 UCD-SNMP-MIB::ucdavis.50.103.1 = "" # snmpwalk -v 1 -c public localhost .1.3.6.1.4.1.2021.51 UCD-SNMP-MIB::ucdavis.51.1.1 = INTEGER: 1 UCD-SNMP-MIB::ucdavis.51.2.1 = STRING: "ps" UCD-SNMP-MIB::ucdavis.51.3.1 = STRING: "/bin/ps" UCD-SNMP-MIB::ucdavis.51.100.1 = INTEGER: 0 UCD-SNMP-MIB::ucdavis.51.101.1 = STRING: " PID TTY TIME CMD" UCD-SNMP-MIB::ucdavis.51.101.2 = STRING: " 1 ? 00:00:01 init" UCD-SNMP-MIB::ucdavis.51.101.3 = STRING: " 2 ? 00:00:00 migration/0" UCD-SNMP-MIB::ucdavis.51.101.4 = STRING: " 3 ? 00:00:00 ksoftirqd/0" UCD-SNMP-MIB::ucdavis.51.101.5 = STRING: " 4 ? 00:00:00 watchdog/0" UCD-SNMP-MIB::ucdavis.51.101.6 = STRING: " 5 ? 00:00:00 migration/1" UCD-SNMP-MIB::ucdavis.51.101.7 = STRING: " 6 ? 00:02:33 ksoftirqd/1" UCD-SNMP-MIB::ucdavis.51.101.8 = STRING: " 7 ? 00:00:00 watchdog/1" UCD-SNMP-MIB::ucdavis.51.101.9 = STRING: " 8 ? 00:00:00 events/0" UCD-SNMP-MIB::ucdavis.51.101.10 = STRING: " 9 ? 00:00:00 events/1" UCD-SNMP-MIB::ucdavis.51.101.11 = STRING: " 10 ? 00:00:00 khelper" UCD-SNMP-MIB::ucdavis.51.101.12 = STRING: " 11 ? 00:00:00 kthread" UCD-SNMP-MIB::ucdavis.51.101.13 = STRING: " 15 ? 00:00:04 kblockd/0" UCD-SNMP-MIB::ucdavis.51.101.14 = STRING: " 16 ? 00:00:00 kblockd/1" UCD-SNMP-MIB::ucdavis.51.101.15 = STRING: " 17 ? 00:00:00 kacpid" UCD-SNMP-MIB::ucdavis.51.101.16 = STRING: " 131 ? 00:00:00 cqueue/0" UCD-SNMP-MIB::ucdavis.51.101.17 = STRING: " 132 ? 00:00:00 cqueue/1" UCD-SNMP-MIB::ucdavis.51.101.18 = STRING: " 135 ? 00:00:00 khubd" UCD-SNMP-MIB::ucdavis.51.101.19 = STRING: " 137 ? 00:00:00 kseriod" UCD-SNMP-MIB::ucdavis.51.101.20 = STRING: " 205 ? 00:00:00 khungtaskd" UCD-SNMP-MIB::ucdavis.51.101.21 = STRING: " 208 ? 00:00:07 kswapd0" UCD-SNMP-MIB::ucdavis.51.101.22 = STRING: " 209 ? 00:00:00 aio/0" UCD-SNMP-MIB::ucdavis.51.101.23 = STRING: " 210 ? 00:00:00 aio/1" UCD-SNMP-MIB::ucdavis.51.101.24 = STRING: " 370 ? 00:00:00 kpsmoused" UCD-SNMP-MIB::ucdavis.51.101.25 = STRING: " 402 ? 00:00:00 scsi_eh_0" UCD-SNMP-MIB::ucdavis.51.101.26 = STRING: " 403 ? 00:01:17 usb-storage" UCD-SNMP-MIB::ucdavis.51.101.27 = STRING: " 408 ? 00:00:00 ata/0" UCD-SNMP-MIB::ucdavis.51.101.28 = STRING: " 409 ? 00:00:00 ata/1" UCD-SNMP-MIB::ucdavis.51.101.29 = STRING: " 410 ? 00:00:00 ata_aux" UCD-SNMP-MIB::ucdavis.51.101.30 = STRING: " 417 ? 00:00:00 kstriped" UCD-SNMP-MIB::ucdavis.51.101.31 = STRING: " 430 ? 00:00:00 ksnapd" UCD-SNMP-MIB::ucdavis.51.101.32 = STRING: " 447 ? " UCD-SNMP-MIB::ucdavis.51.102.1 = INTEGER: 0 UCD-SNMP-MIB::ucdavis.51.103.1 = ""
YUM Remove Orphaned Packages
Find Orphaned Packages
package-cleanup --orphansThen remove the old fc-xx packages that no longer supported with "yum remove".
Fedora 17 Nouveau Driver
X does not load with default Nouveau driver option. Add the following to the kernel option to make it work
nouveau.noaccel=1Alternatively create /etc/modprobe.d/noaccel.conf with
options nouveau noaccel=1
rpmbuild anaconda
$ echo "%_topdir /home/$USER/anaconda/rpm" > ~/.rpmmacros
$ cd ~/anaconda
$ mkdir -p rpm/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
$ rpm -i anaconda-11.1.2.113-1.el5.centos.2.src.rpm #extract source
$ cd rpm/SPECS
$ rpmbuild -ba anaconda.spec
Building loader
$ cd rpm/BUILD/anaconda-11.1.2.209/loader2 $ make loader
Repacking Centos Stage2 Image
Extracting
/usr/sbin/unsquashfs -dest centos-stage2 stage2.img
Repacking
# cd centos-stage2 # tar cf - * .buildstamp | (cd ../centos-stage2-new; tar xfp -) // make change in centos-stage2-new # cd centos-stage2-new # mksquashfs . ../stage2.img.new -all-root -no-fragments -noappend
PCI (Linux)
Identity
Each device is identified by a- domain (0000 each domain can have 256 buses)
- bus number (00)
- device number (00)
- function (0)
# update-pciids #update pci ids # lspci 00:00.0 Host bridge: Intel ... # lspci -tv -[0000:00]-+-00.0 Intel Corporation ... +-01.0-[0000:01-06]----00.0 Intel Corporation 82574L Gigabit Network Connection
Address Spaces
- Configuration
- I/O
- Memory
SYSFS
The address spaces (config, io, memory) can be seen from the sysfs tree.config
# lspci -s 00:1f.3 -x 00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04) 00: 86 80 22 1c 03 00 80 02 04 00 05 0c 00 00 00 00 10: 04 60 52 c2 00 00 00 00 00 00 00 00 00 00 00 00 20: 41 40 00 00 00 00 00 00 00 00 00 00 86 80 22 1c 30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 03 00 00 # od -x /sys/devices/pci0000:00/0000:00:1f.3/config 0000000 8086 1c22 0003 0280 0004 0c05 0000 0000 0000020 6004 c252 0000 0000 0000 0000 0000 0000 0000040 4041 0000 0000 0000 0000 0000 8086 1c22 0000060 0000 0000 0000 0000 0000 0000 030a 0000 0000100 0001 0000 0000 0000 0000 0000 0000 0000 0000120 0000 0000 0000 0000 0000 0000 0000 0000 0000140 0403 0004 0000 0808 0000 0000 0000 0000 0000160 0000 0000 0000 0000 0000 0000 0000 0000 0000200 0004 0000 0000 0000 0000 0000 0000 0000 0000220 0000 0000 0000 0000 0000 0000 0000 0000 * 0000360 0000 0000 0000 0000 0f87 0806 0000 0000
I/O and Memory
These can be mmap'ed# ll /sys/devices/pci0000:00/0000:00:1f.3/resource*
-r--r--r-- 1 root root 4096 Jul 5 17:46 /sys/devices/pci0000:00/0000:00:1f.3/resource
-rw------- 1 root root 256 Jul 5 17:46 /sys/devices/pci0000:00/0000:00:1f.3/resource0
-rw------- 1 root root 32 Jul 5 17:46 /sys/devices/pci0000:00/0000:00:1f.3/resource4
# lspci -v
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 04)
Subsystem: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller
Flags: medium devsel, IRQ 201
Memory at c2526000 (64-bit, non-prefetchable) [size=256]
I/O ports at 4040 [size=32]
resource0 (BAR0) is the memory
resource4 (BAR4) is IO ports
Other Useful
Below is how you can find the driver used for the device# lspci |grep Ether 00:19.0 Ethernet controller: Intel Corporation 82579LM # lspci -s 00:19.0 -n 00:19.0 0200: 8086:1502 (rev 04) # grep 1502 /lib/modules/2.*/modules.pcimap e1000e 0x00008086 0x00001502 0xffffffff 0xffffffff 0x00000000 0x00000000 0x0
Java Basics
Primitive Types
bytechar - 16 bit
short
int
long - 64 bit
boolean
float
double
Variables
- variable of primitive types holds value.
- variable of non-primitive types holds reference.
Variable Storage
- Static - static class variables
- Local - primitives
- Dynamic - non-primitives
Parameters
- All the parameters are pass-by-value (since the variables can only be value or reference; for reference it is a copy of the reference).
- There is no direct way change content of a primitive type with parameter (can wrap with array or object).
Class
Accessibility
publicprivate
protected - subclass and class from the same package.
package - member without any leading keyword get default package access.
- no C++ const method
- no ";" after class {}
Inheritance
- no C++ multiple inheritance
- Object is default base class if no base class is specified. Which is the root base class for all classes.
- super is used to initialize superclass.
import Person;
public class Student extends Person
{
private String major;
public Student(String name, String major)
{
super(name);
this.major=major;
}
}
Static and Dynamic Binding
- virtual by default
void a(); //C++==> virtual void a();
Abstract Methods
abstract a(); //C++==> virtual void a()=0;
Call Superclass Version
super.a(); //C++==> baseName::a();
Final Methods
- Cannot be overriden in a subclass
final void a();
Exceptions
- Java exception class must be a subclass of the java.lang.Exception class (which is a subclass of java.lang.Throwable).
- C++ exception can be of any class.
Features of C++ does not exist in Java
- Preprocessor
- Enumeration Types
- Templates
- Operator Overloading
- Named types (typedef)
- Structs and unions
- const class function member.
Python Basics
Debugging
http://docs.python.org/library/pdb.htmlpython -m pdb my.py # launch pdb after a crash. import pdb; pdb.set_trace() # compile without executing it python -m py_compile test.py
Lib Path
export PYTHONPATH=/home/python $ python Python 2.4.3 (#1, May 24 2008, 13:47:28) [GCC 4.1.2 20070626 (Red Hat 4.1.2-14)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import sys >>> sys.path ['', '/home/python', '/usr/lib/python24.zip', '/usr/lib/python2.4', '/usr/lib/python2.4/plat-linux2', '/usr/lib/python2.4/lib-tk', '/usr/lib/python2.4/lib-dynload', '/usr/lib/python2.4/site-packages', '/usr/lib/python2.4/site-packages/Numeric', '/usr/lib/python2.4/site-packages/gtk-2.0']
Useful
help(int) dir(int) locals() globals()
Variables
everything in python is an object.
All python variables hold value of references to objects.
parameter passing is by value.
String, numbers, tuples are immutable.
Integers, floats, complex numbers, booleans
x = 5 y = 6 print `x`; print "x is %i y is %i" % (x, y)
Lists
a=[1,4,5,6] b=[1,"two",3,["a","b"],4]
Tuples
Same as lists but not changeablea=(1,2) b=(1,"two",3,["a","b"],4)
Dictionaries
a={1:"one", 2:"two"}
a["first"]="one";
list(a.keys())
a.get(1, "not availabe)
Sets
unorder collection of objects.>>> x=set([1,2,3,2,4,1]) >>> x set([1, 2, 3, 4]) >>> 1 in x True >>> 6 in x False
Conditionals
if x < 10: y = 1 elif x > 12: y = 2 else: y = 3
Loops
Forfor x in [1,2,3,4,5]: print x;While
x=5 while x < 10: print x x=x+1
Functions
def func(x, y, z): print (x, y, z) print x, y, z func(1,2,3) mult=lambda x,y: x * y # return is implicit map( lambda x: x*x, [1,2,3,4]) filter(lambda x: x > 3, [ 1,2,3,4,5,6])
Class
class X:
"Sample class"
x=5
def setVal(self,val):
self.x=val
External Commands
os.systemimport os
res=os.system("ls myfile");
if res>>8 != 0:
print "err"
commands
import commands
>>> res, output = commands.getstatusoutput('ls /bin/ls')
>>> res
0
>>> output
'/bin/ls'
>>> commands.getoutput('ls /bin/ls')
'/bin/ls'
>>> commands.getstatus('/bin/ls')
'-rwxr-xr-x. 1 root root 105112 Feb 8 2011 /bin/ls'
Perl Basics
Debugging
-w optionDebugger
perl -w -d my.pl # with perl perl -w -d -e "1;" # no code
Variables
Perl has 3 kinds of variables:- scalar
- array
- hash
scalar
$a=5; local $b='hello';
Array
my @num=(1,2,3);
my @str=("hello", "one");
my @mixed=("hello",1,2);
print $mixed[1];
@colors = ("red","green","blue");
($a, @somecolors) = @colors; # $a is first item; @somecolors are rest of @colors
(@somecolors, $a) = @colors; # @somecolors are @colors; $a is undefined
Hash
%fruit = (
one => "apple",
two => "orange",
three => "peach"
);
@key = keys %fruit;
@value = values %fruit;
print "$fruit{one} $key[1] $value[1]\n";
#hash of hashes
%HoH = (
t1 => { a1 => "a1",
a2 => "a2",},
t2 => { b1 => "b1",
b2 => "b2",},
);
print "$HoH{t1}{a2}\n";
Complex Data Type using Reference
# reference
$multiple = {
m1 => {
onee => "app",
twoo => "ppa",
},
m2 => {
test => "t",
test2 => "y",
},
};
print "$multiple->{m1}{onee} \n";
Conditionals
# if
if ( condition ){
...
}
elsif (condition ) {
...
}
else{
...
}
# unless
unless ( condition )
{
...
}
Loop
Whilewhile (condition) { ... }
until (condition) { ... }
forfor ($i = 0; $i < 10; $i++)
{
...
}
for my $i ('a','b','c'){
print $i;
}
foreach
foreach my $file (@mdfiles)
{
print "$file";
}
foreach (@array) {
print "$_\n";
}
print $list[$_] foreach 0 .. $max;
foreach my $key (keys %hash) {
print "The value of $key is $hash{$key}\n";
}
Operators
Numbers==, !=, <, >, <=, >=Strings
eq, ne, le, ge, lt, gt
Regular Expression
if (/tst/) { ... } # true if $_ contains "tst"
if ($a =~ /hello/) { ... } # true if $a contains "hello"
s/a/b/; # replaces a with b in $_
$a =~ s/a/b/; # replaces a with b in $a
External Commands
#1
$res = system("ls");
#2
my $exam=`mdadm --examine /dev/$dev 2>&1`;
if ($? != 0){
print "error\n";
}
Functions
sub setError($)
{
$errorCode |= shift;
return 1;
}
Bash Programming Basics
Debugging
Start up the shell with the -x option, which will run the entire script in debug mode. Traces of each command plus its arguments are printed to standard output after the commands have been expanded but before they are executed.#!/bin/bash -x #on first line
Variable
a=5 export b='whatever' c="$a $b" d='$a $e' # no substitution local e=56
Array
list=(/tmp/m*)
echo ${#list[@]}
echo ${list[0]}
echo ${list[@]}
echo ${list[*]} # same as @
Conditionals
Empty or unset variableif [[ ${b:-z} == z ]]; then
echo "variable is empty or unset";
fi
String
if [ "a" = "b" ]; then echo yes; else #elif echo no fimultiple condition
if [ "a" = "b" -a "c" == "c" ]; then # string = or == echo "and condition true"; else #elif echo no fi if [ "a" = "b" -o "c" == "c" ]; then # string = or == echo "or condition true"; else #elif echo no fi if [[ $a == "b" && $b == "c" ]]; then echo yes; fi [[ -f $NATION_FILE ]] || fail "No nation file";Numbers
if [ 5 -eq $? ]; then # numbers echo yes ficommands
if grep a * >/dev/null; then echo yes; fi
Loop
For loopfor each in $(ls); do echo $each doneWhile loop
COUNTER=0
while [ $COUNTER -lt 10 ]; do
echo The counter is $COUNTER
COUNTER=$((COUNTER+1))
done
Util
COUNTER=20
until [ $COUNTER -lt 10 ]; do
echo COUNTER $COUNTER
let COUNTER-=1
done
Read Each Line in a Variable
files=$(ls -1) echo "$files" # one line echo $files | while read -r line; do echo $line; done #one line echo "$files" | while read -r line; do echo $line; done # per line echo "$files"|xargs echo #one line echo "$files"|xargs -L1 echo # per line
Functions
myecho()
{
echo $*
echo $@
}
func_parm()
{
[ -z $1 ] || echo parm missing && exit 1
echo parm
}
Signal Handling
handle_int()
{
echo "Control C"
}
trap handle_int SIGINT
Manipulating Strings
http://tldp.org/LDP/abs/html/string-manipulation.html${#String}
${string:position}
${string:position:length}
${string#substring}
${string##substring}
Redirection
1>filename
# Redirect stdout to file "filename."
1>>filename
# Redirect and append stdout to file "filename."
2>filename
# Redirect stderr to file "filename."
2>>filename
# Redirect and append stderr to file "filename."
&>filename
# Redirect both stdout and stderr to file "filename."
# This operator is now functional, as of Bash 4, final release.
M>N
# "M" is a file descriptor, which defaults to 1, if not explicitly set.
# "N" is a filename.
# File descriptor "M" is redirect to file "N."
M>&N
# "M" is a file descriptor, which defaults to 1, if not set.
# "N" is another file descriptor.
Operators
Numbersarg1 OP arg2
OP is one of -eq, -ne, -lt, -le, -gt, or -ge. These arithmetic binary operators return true if arg1 is equal
to, not equal to, less than, less than or equal to, greater than, or greater than or equal to arg2, respec‐
tively. Arg1 and arg2 may be positive or negative integers.
String
string
-n string
True if the length of string is non-zero.
string1 == string2
string1 = string2
True if the strings are equal. = should be used with the test command for POSIX conformance.
string1 != string2
True if the strings are not equal.
string1 < string2
True if string1 sorts before string2 lexicographically.
string1 > string2
True if string1 sorts after string2 lexicographically.
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