github.com/zhuohuang-hust/src-cbuild@v0.0.0-20230105071821-c7aab3e7c840/man/docker-create.1.md (about) 1 % DOCKER(1) Docker User Manuals 2 % Docker Community 3 % JUNE 2014 4 # NAME 5 docker-create - Create a new container 6 7 # SYNOPSIS 8 **docker create** 9 [**-a**|**--attach**[=*[]*]] 10 [**--add-host**[=*[]*]] 11 [**--blkio-weight**[=*[BLKIO-WEIGHT]*]] 12 [**--blkio-weight-device**[=*[]*]] 13 [**--cpu-shares**[=*0*]] 14 [**--cap-add**[=*[]*]] 15 [**--cap-drop**[=*[]*]] 16 [**--cgroup-parent**[=*CGROUP-PATH*]] 17 [**--cidfile**[=*CIDFILE*]] 18 [**--cpu-count**[=*0*]] 19 [**--cpu-percent**[=*0*]] 20 [**--cpu-period**[=*0*]] 21 [**--cpu-quota**[=*0*]] 22 [**--cpu-rt-period**[=*0*]] 23 [**--cpu-rt-runtime**[=*0*]] 24 [**--cpus**[=*0.0*]] 25 [**--cpuset-cpus**[=*CPUSET-CPUS*]] 26 [**--cpuset-mems**[=*CPUSET-MEMS*]] 27 [**--device**[=*[]*]] 28 [**--device-read-bps**[=*[]*]] 29 [**--device-read-iops**[=*[]*]] 30 [**--device-write-bps**[=*[]*]] 31 [**--device-write-iops**[=*[]*]] 32 [**--dns**[=*[]*]] 33 [**--dns-search**[=*[]*]] 34 [**--dns-option**[=*[]*]] 35 [**-e**|**--env**[=*[]*]] 36 [**--entrypoint**[=*ENTRYPOINT*]] 37 [**--env-file**[=*[]*]] 38 [**--expose**[=*[]*]] 39 [**--group-add**[=*[]*]] 40 [**-h**|**--hostname**[=*HOSTNAME*]] 41 [**--help**] 42 [**-i**|**--interactive**] 43 [**--ip**[=*IPv4-ADDRESS*]] 44 [**--ip6**[=*IPv6-ADDRESS*]] 45 [**--ipc**[=*IPC*]] 46 [**--isolation**[=*default*]] 47 [**--kernel-memory**[=*KERNEL-MEMORY*]] 48 [**-l**|**--label**[=*[]*]] 49 [**--label-file**[=*[]*]] 50 [**--link**[=*[]*]] 51 [**--link-local-ip**[=*[]*]] 52 [**--log-driver**[=*[]*]] 53 [**--log-opt**[=*[]*]] 54 [**-m**|**--memory**[=*MEMORY*]] 55 [**--mac-address**[=*MAC-ADDRESS*]] 56 [**--memory-reservation**[=*MEMORY-RESERVATION*]] 57 [**--memory-swap**[=*LIMIT*]] 58 [**--memory-swappiness**[=*MEMORY-SWAPPINESS*]] 59 [**--name**[=*NAME*]] 60 [**--network-alias**[=*[]*]] 61 [**--network**[=*"bridge"*]] 62 [**--oom-kill-disable**] 63 [**--oom-score-adj**[=*0*]] 64 [**-P**|**--publish-all**] 65 [**-p**|**--publish**[=*[]*]] 66 [**--pid**[=*[PID]*]] 67 [**--userns**[=*[]*]] 68 [**--pids-limit**[=*PIDS_LIMIT*]] 69 [**--privileged**] 70 [**--read-only**] 71 [**--restart**[=*RESTART*]] 72 [**--rm**] 73 [**--security-opt**[=*[]*]] 74 [**--storage-opt**[=*[]*]] 75 [**--stop-signal**[=*SIGNAL*]] 76 [**--stop-timeout**[=*TIMEOUT*]] 77 [**--shm-size**[=*[]*]] 78 [**--sysctl**[=*[]*]] 79 [**-t**|**--tty**] 80 [**--tmpfs**[=*[CONTAINER-DIR[:<OPTIONS>]*]] 81 [**-u**|**--user**[=*USER*]] 82 [**--ulimit**[=*[]*]] 83 [**--uts**[=*[]*]] 84 [**-v**|**--volume**[=*[[HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*]] 85 [**--volume-driver**[=*DRIVER*]] 86 [**--volumes-from**[=*[]*]] 87 [**-w**|**--workdir**[=*WORKDIR*]] 88 IMAGE [COMMAND] [ARG...] 89 90 # DESCRIPTION 91 92 Creates a writeable container layer over the specified image and prepares it for 93 running the specified command. The container ID is then printed to STDOUT. This 94 is similar to **docker run -d** except the container is never started. You can 95 then use the **docker start <container_id>** command to start the container at 96 any point. 97 98 The initial status of the container created with **docker create** is 'created'. 99 100 # OPTIONS 101 **-a**, **--attach**=[] 102 Attach to STDIN, STDOUT or STDERR. 103 104 **--add-host**=[] 105 Add a custom host-to-IP mapping (host:ip) 106 107 **--blkio-weight**=*0* 108 Block IO weight (relative weight) accepts a weight value between 10 and 1000. 109 110 **--blkio-weight-device**=[] 111 Block IO weight (relative device weight, format: `DEVICE_NAME:WEIGHT`). 112 113 **--cpu-shares**=*0* 114 CPU shares (relative weight) 115 116 **--cap-add**=[] 117 Add Linux capabilities 118 119 **--cap-drop**=[] 120 Drop Linux capabilities 121 122 **--cgroup-parent**="" 123 Path to cgroups under which the cgroup for the container will be created. If the path is not absolute, the path is considered to be relative to the cgroups path of the init process. Cgroups will be created if they do not already exist. 124 125 **--cidfile**="" 126 Write the container ID to the file 127 128 **--cpu-count**=*0* 129 Limit the number of CPUs available for execution by the container. 130 131 On Windows Server containers, this is approximated as a percentage of total CPU usage. 132 133 On Windows Server containers, the processor resource controls are mutually exclusive, the order of precedence is CPUCount first, then CPUShares, and CPUPercent last. 134 135 **--cpu-percent**=*0* 136 Limit the percentage of CPU available for execution by a container running on a Windows daemon. 137 138 On Windows Server containers, the processor resource controls are mutually exclusive, the order of precedence is CPUCount first, then CPUShares, and CPUPercent last. 139 140 **--cpu-period**=*0* 141 Limit the CPU CFS (Completely Fair Scheduler) period 142 143 Limit the container's CPU usage. This flag tell the kernel to restrict the container's CPU usage to the period you specify. 144 145 **--cpuset-cpus**="" 146 CPUs in which to allow execution (0-3, 0,1) 147 148 **--cpuset-mems**="" 149 Memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems. 150 151 If you have four memory nodes on your system (0-3), use `--cpuset-mems=0,1` 152 then processes in your Docker container will only use memory from the first 153 two memory nodes. 154 155 **--cpu-quota**=*0* 156 Limit the CPU CFS (Completely Fair Scheduler) quota 157 158 **--cpu-rt-period**=0 159 Limit the CPU real-time period in microseconds 160 161 Limit the container's Real Time CPU usage. This flag tell the kernel to restrict the container's Real Time CPU usage to the period you specify. 162 163 **--cpu-rt-runtime**=0 164 Limit the CPU real-time runtime in microseconds 165 166 Limit the containers Real Time CPU usage. This flag tells the kernel to limit the amount of time in a given CPU period Real Time tasks may consume. Ex: 167 Period of 1,000,000us and Runtime of 950,000us means that this container could consume 95% of available CPU and leave the remaining 5% to normal priority tasks. 168 169 The sum of all runtimes across containers cannot exceed the amount allotted to the parent cgroup. 170 171 **--cpus**=0.0 172 Number of CPUs. The default is *0.0*. 173 174 **--device**=[] 175 Add a host device to the container (e.g. --device=/dev/sdc:/dev/xvdc:rwm) 176 177 **--device-read-bps**=[] 178 Limit read rate (bytes per second) from a device (e.g. --device-read-bps=/dev/sda:1mb) 179 180 **--device-read-iops**=[] 181 Limit read rate (IO per second) from a device (e.g. --device-read-iops=/dev/sda:1000) 182 183 **--device-write-bps**=[] 184 Limit write rate (bytes per second) to a device (e.g. --device-write-bps=/dev/sda:1mb) 185 186 **--device-write-iops**=[] 187 Limit write rate (IO per second) to a device (e.g. --device-write-iops=/dev/sda:1000) 188 189 **--dns**=[] 190 Set custom DNS servers 191 192 **--dns-option**=[] 193 Set custom DNS options 194 195 **--dns-search**=[] 196 Set custom DNS search domains (Use --dns-search=. if you don't wish to set the search domain) 197 198 **-e**, **--env**=[] 199 Set environment variables 200 201 **--entrypoint**="" 202 Overwrite the default ENTRYPOINT of the image 203 204 **--env-file**=[] 205 Read in a line-delimited file of environment variables 206 207 **--expose**=[] 208 Expose a port or a range of ports (e.g. --expose=3300-3310) from the container without publishing it to your host 209 210 **--group-add**=[] 211 Add additional groups to run as 212 213 **-h**, **--hostname**="" 214 Container host name 215 216 **--help** 217 Print usage statement 218 219 **-i**, **--interactive**=*true*|*false* 220 Keep STDIN open even if not attached. The default is *false*. 221 222 **--ip**="" 223 Sets the container's interface IPv4 address (e.g. 172.23.0.9) 224 225 It can only be used in conjunction with **--net** for user-defined networks 226 227 **--ip6**="" 228 Sets the container's interface IPv6 address (e.g. 2001:db8::1b99) 229 230 It can only be used in conjunction with **--net** for user-defined networks 231 232 **--ipc**="" 233 Default is to create a private IPC namespace (POSIX SysV IPC) for the container 234 'container:<name|id>': reuses another container shared memory, semaphores and message queues 235 'host': use the host shared memory,semaphores and message queues inside the container. Note: the host mode gives the container full access to local shared memory and is therefore considered insecure. 236 237 **--isolation**="*default*" 238 Isolation specifies the type of isolation technology used by containers. Note 239 that the default on Windows server is `process`, and the default on Windows client 240 is `hyperv`. Linux only supports `default`. 241 242 **--kernel-memory**="" 243 Kernel memory limit (format: `<number>[<unit>]`, where unit = b, k, m or g) 244 245 Constrains the kernel memory available to a container. If a limit of 0 246 is specified (not using `--kernel-memory`), the container's kernel memory 247 is not limited. If you specify a limit, it may be rounded up to a multiple 248 of the operating system's page size and the value can be very large, 249 millions of trillions. 250 251 **-l**, **--label**=[] 252 Adds metadata to a container (e.g., --label=com.example.key=value) 253 254 **--label-file**=[] 255 Read labels from a file. Delimit each label with an EOL. 256 257 **--link**=[] 258 Add link to another container in the form of <name or id>:alias or just 259 <name or id> in which case the alias will match the name. 260 261 **--link-local-ip**=[] 262 Add one or more link-local IPv4/IPv6 addresses to the container's interface 263 264 **--log-driver**="*json-file*|*syslog*|*journald*|*gelf*|*fluentd*|*awslogs*|*splunk*|*etwlogs*|*gcplogs*|*none*" 265 Logging driver for the container. Default is defined by daemon `--log-driver` flag. 266 **Warning**: the `docker logs` command works only for the `json-file` and 267 `journald` logging drivers. 268 269 **--log-opt**=[] 270 Logging driver specific options. 271 272 **-m**, **--memory**="" 273 Memory limit (format: <number>[<unit>], where unit = b, k, m or g) 274 275 Allows you to constrain the memory available to a container. If the host 276 supports swap memory, then the **-m** memory setting can be larger than physical 277 RAM. If a limit of 0 is specified (not using **-m**), the container's memory is 278 not limited. The actual limit may be rounded up to a multiple of the operating 279 system's page size (the value would be very large, that's millions of trillions). 280 281 **--mac-address**="" 282 Container MAC address (e.g. 92:d0:c6:0a:29:33) 283 284 **--memory-reservation**="" 285 Memory soft limit (format: <number>[<unit>], where unit = b, k, m or g) 286 287 After setting memory reservation, when the system detects memory contention 288 or low memory, containers are forced to restrict their consumption to their 289 reservation. So you should always set the value below **--memory**, otherwise the 290 hard limit will take precedence. By default, memory reservation will be the same 291 as memory limit. 292 293 **--memory-swap**="LIMIT" 294 A limit value equal to memory plus swap. Must be used with the **-m** 295 (**--memory**) flag. The swap `LIMIT` should always be larger than **-m** 296 (**--memory**) value. 297 298 The format of `LIMIT` is `<number>[<unit>]`. Unit can be `b` (bytes), 299 `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you don't specify a 300 unit, `b` is used. Set LIMIT to `-1` to enable unlimited swap. 301 302 **--memory-swappiness**="" 303 Tune a container's memory swappiness behavior. Accepts an integer between 0 and 100. 304 305 **--name**="" 306 Assign a name to the container 307 308 **--net**="*bridge*" 309 Set the Network mode for the container 310 'bridge': create a network stack on the default Docker bridge 311 'none': no networking 312 'container:<name|id>': reuse another container's network stack 313 'host': use the Docker host network stack. Note: the host mode gives the container full access to local system services such as D-bus and is therefore considered insecure. 314 '<network-name>|<network-id>': connect to a user-defined network 315 316 **--network-alias**=[] 317 Add network-scoped alias for the container 318 319 **--oom-kill-disable**=*true*|*false* 320 Whether to disable OOM Killer for the container or not. 321 322 **--oom-score-adj**="" 323 Tune the host's OOM preferences for containers (accepts -1000 to 1000) 324 325 **-P**, **--publish-all**=*true*|*false* 326 Publish all exposed ports to random ports on the host interfaces. The default is *false*. 327 328 **-p**, **--publish**=[] 329 Publish a container's port, or a range of ports, to the host 330 format: ip:hostPort:containerPort | ip::containerPort | hostPort:containerPort | containerPort 331 Both hostPort and containerPort can be specified as a range of ports. 332 When specifying ranges for both, the number of container ports in the range must match the number of host ports in the range. (e.g., `-p 1234-1236:1234-1236/tcp`) 333 (use 'docker port' to see the actual mapping) 334 335 **--pid**="" 336 Set the PID mode for the container 337 Default is to create a private PID namespace for the container 338 'container:<name|id>': join another container's PID namespace 339 'host': use the host's PID namespace for the container. Note: the host mode gives the container full access to local PID and is therefore considered insecure. 340 341 **--userns**="" 342 Set the usernamespace mode for the container when `userns-remap` option is enabled. 343 **host**: use the host usernamespace and enable all privileged options (e.g., `pid=host` or `--privileged`). 344 345 **--pids-limit**="" 346 Tune the container's pids limit. Set `-1` to have unlimited pids for the container. 347 348 **--privileged**=*true*|*false* 349 Give extended privileges to this container. The default is *false*. 350 351 **--read-only**=*true*|*false* 352 Mount the container's root filesystem as read only. 353 354 **--restart**="*no*" 355 Restart policy to apply when a container exits (no, on-failure[:max-retry], always, unless-stopped). 356 357 **--rm**=*true*|*false* 358 Automatically remove the container when it exits. The default is *false*. 359 360 **--shm-size**="" 361 Size of `/dev/shm`. The format is `<number><unit>`. `number` must be greater than `0`. 362 Unit is optional and can be `b` (bytes), `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). If you omit the unit, the system uses bytes. 363 If you omit the size entirely, the system uses `64m`. 364 365 **--security-opt**=[] 366 Security Options 367 368 "label:user:USER" : Set the label user for the container 369 "label:role:ROLE" : Set the label role for the container 370 "label:type:TYPE" : Set the label type for the container 371 "label:level:LEVEL" : Set the label level for the container 372 "label:disable" : Turn off label confinement for the container 373 "no-new-privileges" : Disable container processes from gaining additional privileges 374 "seccomp:unconfined" : Turn off seccomp confinement for the container 375 "seccomp:profile.json : White listed syscalls seccomp Json file to be used as a seccomp filter 376 377 **--storage-opt**=[] 378 Storage driver options per container 379 380 $ docker create -it --storage-opt size=120G fedora /bin/bash 381 382 This (size) will allow to set the container rootfs size to 120G at creation time. 383 This option is only available for the `devicemapper`, `btrfs`, `overlay2` and `zfs` graph drivers. 384 For the `devicemapper`, `btrfs` and `zfs` storage drivers, user cannot pass a size less than the Default BaseFS Size. 385 For the `overlay2` storage driver, the size option is only available if the backing fs is `xfs` and mounted with the `pquota` mount option. 386 Under these conditions, user can pass any size less then the backing fs size. 387 388 **--stop-signal**=*SIGTERM* 389 Signal to stop a container. Default is SIGTERM. 390 391 **--stop-timeout**=*10* 392 Timeout (in seconds) to stop a container. Default is 10. 393 394 **--sysctl**=SYSCTL 395 Configure namespaced kernel parameters at runtime 396 397 IPC Namespace - current sysctls allowed: 398 399 kernel.msgmax, kernel.msgmnb, kernel.msgmni, kernel.sem, kernel.shmall, kernel.shmmax, kernel.shmmni, kernel.shm_rmid_forced 400 Sysctls beginning with fs.mqueue.* 401 402 Note: if you use --ipc=host using these sysctls will not be allowed. 403 404 Network Namespace - current sysctls allowed: 405 Sysctls beginning with net.* 406 407 Note: if you use --net=host using these sysctls will not be allowed. 408 409 **-t**, **--tty**=*true*|*false* 410 Allocate a pseudo-TTY. The default is *false*. 411 412 **--tmpfs**=[] Create a tmpfs mount 413 414 Mount a temporary filesystem (`tmpfs`) mount into a container, for example: 415 416 $ docker run -d --tmpfs /tmp:rw,size=787448k,mode=1777 my_image 417 418 This command mounts a `tmpfs` at `/tmp` within the container. The supported mount 419 options are the same as the Linux default `mount` flags. If you do not specify 420 any options, the systems uses the following options: 421 `rw,noexec,nosuid,nodev,size=65536k`. 422 423 **-u**, **--user**="" 424 Sets the username or UID used and optionally the groupname or GID for the specified command. 425 426 The followings examples are all valid: 427 --user [user | user:group | uid | uid:gid | user:gid | uid:group ] 428 429 Without this argument root user will be used in the container by default. 430 431 **--ulimit**=[] 432 Ulimit options 433 434 **--uts**=*host* 435 Set the UTS mode for the container 436 **host**: use the host's UTS namespace inside the container. 437 Note: the host mode gives the container access to changing the host's hostname and is therefore considered insecure. 438 439 **-v**|**--volume**[=*[[HOST-DIR:]CONTAINER-DIR[:OPTIONS]]*] 440 Create a bind mount. If you specify, ` -v /HOST-DIR:/CONTAINER-DIR`, Docker 441 bind mounts `/HOST-DIR` in the host to `/CONTAINER-DIR` in the Docker 442 container. If 'HOST-DIR' is omitted, Docker automatically creates the new 443 volume on the host. The `OPTIONS` are a comma delimited list and can be: 444 445 * [rw|ro] 446 * [z|Z] 447 * [`[r]shared`|`[r]slave`|`[r]private`] 448 449 The `CONTAINER-DIR` must be an absolute path such as `/src/docs`. The `HOST-DIR` 450 can be an absolute path or a `name` value. A `name` value must start with an 451 alphanumeric character, followed by `a-z0-9`, `_` (underscore), `.` (period) or 452 `-` (hyphen). An absolute path starts with a `/` (forward slash). 453 454 If you supply a `HOST-DIR` that is an absolute path, Docker bind-mounts to the 455 path you specify. If you supply a `name`, Docker creates a named volume by that 456 `name`. For example, you can specify either `/foo` or `foo` for a `HOST-DIR` 457 value. If you supply the `/foo` value, Docker creates a bind-mount. If you 458 supply the `foo` specification, Docker creates a named volume. 459 460 You can specify multiple **-v** options to mount one or more mounts to a 461 container. To use these same mounts in other containers, specify the 462 **--volumes-from** option also. 463 464 You can add `:ro` or `:rw` suffix to a volume to mount it read-only or 465 read-write mode, respectively. By default, the volumes are mounted read-write. 466 See examples. 467 468 Labeling systems like SELinux require that proper labels are placed on volume 469 content mounted into a container. Without a label, the security system might 470 prevent the processes running inside the container from using the content. By 471 default, Docker does not change the labels set by the OS. 472 473 To change a label in the container context, you can add either of two suffixes 474 `:z` or `:Z` to the volume mount. These suffixes tell Docker to relabel file 475 objects on the shared volumes. The `z` option tells Docker that two containers 476 share the volume content. As a result, Docker labels the content with a shared 477 content label. Shared volume labels allow all containers to read/write content. 478 The `Z` option tells Docker to label the content with a private unshared label. 479 Only the current container can use a private volume. 480 481 By default bind mounted volumes are `private`. That means any mounts done 482 inside container will not be visible on host and vice-a-versa. One can change 483 this behavior by specifying a volume mount propagation property. Making a 484 volume `shared` mounts done under that volume inside container will be 485 visible on host and vice-a-versa. Making a volume `slave` enables only one 486 way mount propagation and that is mounts done on host under that volume 487 will be visible inside container but not the other way around. 488 489 To control mount propagation property of volume one can use `:[r]shared`, 490 `:[r]slave` or `:[r]private` propagation flag. Propagation property can 491 be specified only for bind mounted volumes and not for internal volumes or 492 named volumes. For mount propagation to work source mount point (mount point 493 where source dir is mounted on) has to have right propagation properties. For 494 shared volumes, source mount point has to be shared. And for slave volumes, 495 source mount has to be either shared or slave. 496 497 Use `df <source-dir>` to figure out the source mount and then use 498 `findmnt -o TARGET,PROPAGATION <source-mount-dir>` to figure out propagation 499 properties of source mount. If `findmnt` utility is not available, then one 500 can look at mount entry for source mount point in `/proc/self/mountinfo`. Look 501 at `optional fields` and see if any propagaion properties are specified. 502 `shared:X` means mount is `shared`, `master:X` means mount is `slave` and if 503 nothing is there that means mount is `private`. 504 505 To change propagation properties of a mount point use `mount` command. For 506 example, if one wants to bind mount source directory `/foo` one can do 507 `mount --bind /foo /foo` and `mount --make-private --make-shared /foo`. This 508 will convert /foo into a `shared` mount point. Alternatively one can directly 509 change propagation properties of source mount. Say `/` is source mount for 510 `/foo`, then use `mount --make-shared /` to convert `/` into a `shared` mount. 511 512 > **Note**: 513 > When using systemd to manage the Docker daemon's start and stop, in the systemd 514 > unit file there is an option to control mount propagation for the Docker daemon 515 > itself, called `MountFlags`. The value of this setting may cause Docker to not 516 > see mount propagation changes made on the mount point. For example, if this value 517 > is `slave`, you may not be able to use the `shared` or `rshared` propagation on 518 > a volume. 519 520 521 To disable automatic copying of data from the container path to the volume, use 522 the `nocopy` flag. The `nocopy` flag can be set on bind mounts and named volumes. 523 524 **--volume-driver**="" 525 Container's volume driver. This driver creates volumes specified either from 526 a Dockerfile's `VOLUME` instruction or from the `docker run -v` flag. 527 See **docker-volume-create(1)** for full details. 528 529 **--volumes-from**=[] 530 Mount volumes from the specified container(s) 531 532 **-w**, **--workdir**="" 533 Working directory inside the container 534 535 # EXAMPLES 536 537 ## Specify isolation technology for container (--isolation) 538 539 This option is useful in situations where you are running Docker containers on 540 Windows. The `--isolation=<value>` option sets a container's isolation 541 technology. On Linux, the only supported is the `default` option which uses 542 Linux namespaces. On Microsoft Windows, you can specify these values: 543 544 * `default`: Use the value specified by the Docker daemon's `--exec-opt` . If the `daemon` does not specify an isolation technology, Microsoft Windows uses `process` as its default value. 545 * `process`: Namespace isolation only. 546 * `hyperv`: Hyper-V hypervisor partition-based isolation. 547 548 Specifying the `--isolation` flag without a value is the same as setting `--isolation="default"`. 549 550 # HISTORY 551 August 2014, updated by Sven Dowideit <SvenDowideit@home.org.au> 552 September 2014, updated by Sven Dowideit <SvenDowideit@home.org.au> 553 November 2014, updated by Sven Dowideit <SvenDowideit@home.org.au>