Related
If I had 20 directories under trunk/ with lots of files in each and only needed 3 of those directories, would it be possible to do a Subversion checkout with only those 3 directories under trunk?
Indeed, thanks to the comments to my post here, it looks like sparse directories are the way to go. I believe the following should do it:
svn checkout --depth empty http://svnserver/trunk/proj
svn update --set-depth infinity proj/foo
svn update --set-depth infinity proj/bar
svn update --set-depth infinity proj/baz
Alternatively, --depth immediates instead of empty checks out files and directories in trunk/proj without their contents. That way you can see which directories exist in the repository.
As mentioned in #zigdon's answer, you can also do a non-recursive checkout. This is an older and less flexible way to achieve a similar effect:
svn checkout --non-recursive http://svnserver/trunk/proj
svn update trunk/foo
svn update trunk/bar
svn update trunk/baz
Subversion 1.5 introduces sparse checkouts which may be something you might find useful. From the documentation:
... sparse directories (or shallow checkouts) ... allows you to easily check out a working copy—or a portion of a working copy—more shallowly than full recursion, with the freedom to bring in previously ignored files and subdirectories at a later time.
I wrote a script to automate complex sparse checkouts.
#!/usr/bin/env python
'''
This script makes a sparse checkout of an SVN tree in the current working directory.
Given a list of paths in an SVN repository, it will:
1. Checkout the common root directory
2. Update with depth=empty for intermediate directories
3. Update with depth=infinity for the leaf directories
'''
import os
import getpass
import pysvn
__author__ = "Karl Ostmo"
__date__ = "July 13, 2011"
# =============================================================================
# XXX The os.path.commonprefix() function does not behave as expected!
# See here: http://mail.python.org/pipermail/python-dev/2002-December/030947.html
# and here: http://nedbatchelder.com/blog/201003/whats_the_point_of_ospathcommonprefix.html
# and here (what ever happened?): http://bugs.python.org/issue400788
from itertools import takewhile
def allnamesequal(name):
return all(n==name[0] for n in name[1:])
def commonprefix(paths, sep='/'):
bydirectorylevels = zip(*[p.split(sep) for p in paths])
return sep.join(x[0] for x in takewhile(allnamesequal, bydirectorylevels))
# =============================================================================
def getSvnClient(options):
password = options.svn_password
if not password:
password = getpass.getpass('Enter SVN password for user "%s": ' % options.svn_username)
client = pysvn.Client()
client.callback_get_login = lambda realm, username, may_save: (True, options.svn_username, password, True)
return client
# =============================================================================
def sparse_update_with_feedback(client, new_update_path):
revision_list = client.update(new_update_path, depth=pysvn.depth.empty)
# =============================================================================
def sparse_checkout(options, client, repo_url, sparse_path, local_checkout_root):
path_segments = sparse_path.split(os.sep)
path_segments.reverse()
# Update the middle path segments
new_update_path = local_checkout_root
while len(path_segments) > 1:
path_segment = path_segments.pop()
new_update_path = os.path.join(new_update_path, path_segment)
sparse_update_with_feedback(client, new_update_path)
if options.verbose:
print "Added internal node:", path_segment
# Update the leaf path segment, fully-recursive
leaf_segment = path_segments.pop()
new_update_path = os.path.join(new_update_path, leaf_segment)
if options.verbose:
print "Will now update with 'recursive':", new_update_path
update_revision_list = client.update(new_update_path)
if options.verbose:
for revision in update_revision_list:
print "- Finished updating %s to revision: %d" % (new_update_path, revision.number)
# =============================================================================
def group_sparse_checkout(options, client, repo_url, sparse_path_list, local_checkout_root):
if not sparse_path_list:
print "Nothing to do!"
return
checkout_path = None
if len(sparse_path_list) > 1:
checkout_path = commonprefix(sparse_path_list)
else:
checkout_path = sparse_path_list[0].split(os.sep)[0]
root_checkout_url = os.path.join(repo_url, checkout_path).replace("\\", "/")
revision = client.checkout(root_checkout_url, local_checkout_root, depth=pysvn.depth.empty)
checkout_path_segments = checkout_path.split(os.sep)
for sparse_path in sparse_path_list:
# Remove the leading path segments
path_segments = sparse_path.split(os.sep)
start_segment_index = 0
for i, segment in enumerate(checkout_path_segments):
if segment == path_segments[i]:
start_segment_index += 1
else:
break
pruned_path = os.sep.join(path_segments[start_segment_index:])
sparse_checkout(options, client, repo_url, pruned_path, local_checkout_root)
# =============================================================================
if __name__ == "__main__":
from optparse import OptionParser
usage = """%prog [path2] [more paths...]"""
default_repo_url = "http://svn.example.com/MyRepository"
default_checkout_path = "sparse_trunk"
parser = OptionParser(usage)
parser.add_option("-r", "--repo_url", type="str", default=default_repo_url, dest="repo_url", help='Repository URL (default: "%s")' % default_repo_url)
parser.add_option("-l", "--local_path", type="str", default=default_checkout_path, dest="local_path", help='Local checkout path (default: "%s")' % default_checkout_path)
default_username = getpass.getuser()
parser.add_option("-u", "--username", type="str", default=default_username, dest="svn_username", help='SVN login username (default: "%s")' % default_username)
parser.add_option("-p", "--password", type="str", dest="svn_password", help="SVN login password")
parser.add_option("-v", "--verbose", action="store_true", default=False, dest="verbose", help="Verbose output")
(options, args) = parser.parse_args()
client = getSvnClient(options)
group_sparse_checkout(
options,
client,
options.repo_url,
map(os.path.relpath, args),
options.local_path)
Or do a non-recursive checkout of /trunk, then just do a manual update on the 3 directories you need.
If you already have the full local copy, you can remove unwanted sub folders by using --set-depth command.
svn update --set-depth=exclude www
See: http://blogs.collab.net/subversion/sparse-directories-now-with-exclusion
The set-depth command support multipile paths.
Updating the root local copy will not change the depth of the modified folder.
To restore the folder to being recusively checkingout, you could use --set-depth again with infinity param.
svn update --set-depth=infinity www
I'm adding this information for those using the TortoiseSvn tool: to obtain the OP same functionality, you can use the Choose items... button in the Checkout Depth section of the Checkout function, as shown in the following screenshot:
Sort of. As Bobby says:
svn co file:///.../trunk/foo file:///.../trunk/bar file:///.../trunk/hum
will get the folders, but you will get separate folders from a subversion perspective. You will have to go separate commits and updates on each subfolder.
I don't believe you can checkout a partial tree and then work with the partial tree as a single entity.
Not in any especially useful way, no. You can check out subtrees (as in Bobby Jack's suggestion), but then you lose the ability to update/commit them atomically; to do that, they need to be placed under their common parent, and as soon as you check out the common parent, you'll download everything under that parent. Non-recursive isn't a good option, because you want updates and commits to be recursive.
I'm using Sqoop to update a table in oracle with UpdateOnly options.
Have tried many suggestions mentioned on various site but it still doesn't work.
The code is as given below...
SqoopOptions sqoopClient = new SqoopOptions();
sqoopClient.setFieldsTerminatedBy(fieldDelim);
sqoopClient.setLinesTerminatedBy(lineTerminator);
sqoopClient.setTableName(tableName);
sqoopClient.setColumns(columnArray);
//columnArray contains the list of columns to update including the update
sqoopClient.setUpdateKeyCol("id");
sqoopClient.setUpdateMode(SqoopOptions.UpdateMode.UpdateOnly);
sqoopClient.setExportDir(inputDirForExportJob); // gets input from this directory in the HDFS
sqoopClient.setFileLayout(com.cloudera.sqoop.SqoopOptions.FileLayout.TextFile);
com.cloudera.sqoop.tool.SqoopTool sqoop_tool = com.cloudera.sqoop.tool.SqoopTool.getTool("export");
org.apache.sqoop.Sqoop sqoop_export = new org.apache.sqoop.Sqoop(sqoop_tool, hadoop_config, sqoopClient);
int status = 1;
try{
status = new ExportTool().run(sqoopClient);
}
return status;
Even tried executing throug command line
sqoop export --connect jdbc:oracle:thin:#192.168.2.175:1521:OPS1 --username ZYCDEV --password ZYCDEV --table abhishek_emp --update-key id --export-dir /user/abhisheks/bcr/check.txt --input-fields-terminated-by '|' --columns 'id,description' --update-mode updateonly
Still same issue..
The cloudera version I'm using is .. sqoop-1.4.2-cdh4.2.0.jar..
It was a bug. Tried with newer version of sqoop and it's running fine.
I'm trying add a Java installation on my Yocto build. I would like to run on my embedded system a Java application I developed but I can't correctly install Java.
When I try to run java I get the following:
./java: No such file or directory
I googled for a solution and found that I need to install libc6 32 bit version.
I proceeded to modify my local.conf file as following:
MACHINE ??= "intel-corei7-64"
require conf/multilib.conf
MULTILIBS = "multilib:lib32"
DEFAULTTUNE_virtclass-multilib-lib32 = "x86"
DISTRO ?= "poky"
PACKAGE_CLASSES ?= "package_rpm"
SDKMACHINE ?= "x86_64"
EXTRA_IMAGE_FEATURES ?= "debug-tweaks"
USER_CLASSES ?= "buildstats image-mklibs image-prelink"
PATCHRESOLVE = "noop"
BB_DISKMON_DIRS = "\
STOPTASKS,${TMPDIR},1G,100K \
STOPTASKS,${DL_DIR},1G,100K \
STOPTASKS,${SSTATE_DIR},1G,100K \
STOPTASKS,/tmp,100M,100K \
ABORT,${TMPDIR},100M,1K \
ABORT,${DL_DIR},100M,1K \
ABORT,${SSTATE_DIR},100M,1K \
ABORT,/tmp,10M,1K"
PACKAGECONFIG_append_pn-qemu-native = " sdl"
PACKAGECONFIG_append_pn-nativesdk-qemu = " sdl"
CONF_VERSION = "1"
CORE_IMAGE_EXTRA_INSTALL = " lib32-glibc"
CORE_IMAGE_EXTRA_INSTALL += "opencv opencv-samples libopencv-core-dev libopencv-highgui-dev libopencv-imgproc-dev libopencv-objdetect-dev libopencv-ml-dev"
But i get this error:
Build Configuration:
BB_VERSION = "1.32.0"
BUILD_SYS = "x86_64-linux"
NATIVELSBSTRING = "universal-4.8"
TARGET_SYS = "x86_64-poky-linux"
MACHINE = "intel-corei7-64"
DISTRO = "poky"
DISTRO_VERSION = "2.2.1"
TUNE_FEATURES = "m64 corei7"
TARGET_FPU = ""
meta
meta-poky
meta-yocto-bsp = "morty:924e576b8930fd2268d85f0b151e5f68a3c2afce"
meta-intel = "morty:6add41510412ca196efb3e4f949d403a8b6f35d7"
meta-oe = "morty:fe5c83312de11e80b85680ef237f8acb04b4b26e"
meta-intel-realsense = "morty:2c0dfe9690d2871214fba9c1c32980a5eb89a421"
Initialising tasks: 100% |#####################################################################################################################################################################################################| Time: 0:00:22
NOTE: Executing SetScene Tasks
NOTE: Executing RunQueue Tasks
ERROR: rmc-1.0-r0 do_package: QA Issue: rmc: Files/directories were installed but not shipped in any package:
/usr/lib
/usr/lib/librmclefi.a
/usr/lib/librsmpefi.a
Please set FILES such that these items are packaged. Alternatively if they are unneeded, avoid installing them or delete them within do_install.
rmc: 3 installed and not shipped files. [installed-vs-shipped]
ERROR: rmc-1.0-r0 do_package: Fatal QA errors found, failing task.
ERROR: rmc-1.0-r0 do_package: Function failed: do_package
ERROR: Logfile of failure stored in: /home/dalben/WorkingBuild/poky/filec/tmp/work/corei7-64-poky-linux/rmc/1.0-r0/temp/log.do_package.16424
ERROR: Task (/home/dalben/WorkingBuild/poky/meta-intel/common/recipes-bsp/rmc/rmc.bb:do_package) failed with exit code '1'
NOTE: Tasks Summary: Attempted 2954 tasks of which 2937 didn't need to be rerun and 1 failed.
Summary: 1 task failed:
/home/dalben/WorkingBuild/poky/meta-intel/common/recipes-bsp/rmc/rmc.bb:do_package
Summary: There were 3 ERROR messages shown, returning a non-zero exit code.
Any help is appreciated.
EDIT: Updated question here.
For your information, you will need to do a lot of work in putting Java into your image.
Your current image does not have any java related programs installed since I do not see meta-java in your compile process.
CORE_IMAGE_EXTRA_INSTALL is restricted to OE Core images; So if you have your own image recipe, the variable will does not work unless you inherit core-image.bbclass
Here is an example on putting "openjdk-7-jre" to the image: http://wiki.hioproject.org/index.php?title=OpenHAB:_WeMo_Switch
The key elements are: meta-java, meta-oracle-java .
You will need to add them to your conf/bblayers.conf
BBLAYERS = " \
${BSPDIR}/sources/meta-java \
${BSPDIR}/sources/meta-oracle-java \
"
In conf/local.conf, add this line to install openjdk-7-jre.
IMAGE_INSTALL_append = " openjdk-7-jre "
To add more on what you need, check on https://layers.openembedded.org/layerindex/branch/master/layers/
Goal: check java's version on a machine (I can get this from java -version). Compare it with latest available from java website
I would like to know if there is any way I can check for latest Java releases assuming that I have JRE/JDK installed on a machine.
If I can do this through Java itself, my solution would become platform independent. I could use java.net.URL class to send a request to Java website and get the HTML, however the response would be dynamic as Oracle can change their website and styles and possibly will have maintenance issues in long run.
I have looked at javatester.org, but I would not want it through an applet but through command line (which I can add to a script).
Through javacpl.exe, I can schedule periodic checks, but I would like to do it on demand.
The answer is actually quite simple. http://java.com/en/download/testjava.jsp issues a request to http://java.com/applet/JreCurrentVersion2.txt. That file currently contains a single version number: '1.7.0_11'...which is the latest and greatest, indeed.
Java code example
try (BufferedReader br = new BufferedReader(new InputStreamReader(new URL(
"http://java.com/applet/JreCurrentVersion2.txt").openStream()))) {
String fullVersion = br.readLine();
String version = fullVersion.split("_")[0];
String revision = fullVersion.split("_")[1];
System.out.println("Version " + version + " revision " + revision);
} catch (IOException e) {
// handle properly
}
Update 2014-03-20
Eventhough Java 8 was recently released http://java.com/applet/JreCurrentVersion2.txt currently still returns 1.7.0_51.
Update 2016-07-13
Looks like we need to come back to this every few months... Currently you need to scan http://java.com/en/download/installed8.jsp for a JavaScript variable latest8Version. So, you could run curl -s https://java.com/en/download/installed8.jsp | grep latest8Version.
Update 2018-08-19
http://javadl-esd-secure.oracle.com/update/baseline.version is another hot spot as mentioned in some other answer.
An URL very similar to the now defunct "JreCurrentVersion2.txt":
http://javadl-esd-secure.oracle.com/update/baseline.version
The contents of the link look like this:
1.8.0_111
1.7.0_121
1.6.0_131
1.5.0_99
1.4.2_43
You can easily parse the contents to find the latest JRE versions.
UPDATE: I don't recommend this method because this JRE is the one that has the Ask.com toolbar. You're better off downloading it yourself and distributing it yourself.
The jusched.exe program accesses the following URL to find out what versions are available. I think it's less likely to change because jusched is installed on millions of computers.
https://javadl-esd-secure.oracle.com/update/1.7.0/map-m-1.7.0.xml
Here is a snippet of what it returns for me:
<?xml version="1.0" encoding="ISO-8859-1" standalone="yes" ?>
<java-update-map version="1.0">
<mapping>
<version>1.7.0_17</version>
<url>https://javadl-esd-secure.oracle.com/update/1.7.0/au-descriptor-1.7.0_25-b17.xml</url>
</mapping>
<mapping>
<version>1.7.0_21</version>
<url>https://javadl-esd-secure.oracle.com/update/1.7.0/au-descriptor-1.7.0_25-b17.xml</url>
</mapping>
</java-update-map>
To get the actual version that it is pointing to you have to fetch the above URL. Here is another snippet of what this XML looks like:
xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- XML file to be staged anywhere, and pointed to by map.xml file -->
<java-update>
<information version="1.0" xml:lang="en">
<caption>Java Update - Update Available</caption>
<title>Java Update Available</title>
<description>Java 7 Update 25 is ready to install. Installing Java 7 Update 25 might uninstall the latest Java 6 from your system. Click the Install button to update Java now. If you wish to update Java later, click the Later button.</description>
<moreinfo>http://java.com/moreinfolink</moreinfo>
<AlertTitle>Java Update Available</AlertTitle>
<AlertText>A new version of Java is ready to be installed.</AlertText>
<moreinfotxt>More information...</moreinfotxt>
<url>http://javadl.sun.com/webapps/download/GetFile/1.7.0_25-b17/windows-i586/jre-7u25-windows-i586-iftw.exe</url>
<version>1.7.0_25-b17</version>
<post-status>https://nometrics.java.com</post-status>
<cntry-lookup>http://rps-svcs.sun.com/services/countrylookup</cntry-lookup>
<predownload></predownload>
<options>/installmethod=jau FAMILYUPGRADE=1 SPWEB=http://javadl-esd.sun.com/update/1.7.0/sp-1.7.0_25-b17</options>
<urlinfo>24595ec7f861bc67e572f1e4ad3992441335e1a7</urlinfo>
</information>
</java-update>
The version tag contains the full version number.
You could parse the Java SE Downloads page to extract the Java versions.
That way, you get the version of both JDK6 and JDK7, which allows you to test your particular JDK (6 or 7) against the latest Oracle one.
(As opposed to the Free Java Download page, which only lists the JDK7)
Her is a crude script in Go, which you can compile on Windows, Unix, MacOs into a single independent executable, and use within a command line or a script:
package main
import (
"bytes"
"encoding/xml"
"fmt"
"io/ioutil"
"net/http"
"os/exec"
"regexp"
)
type Jdk struct {
Url string
Ver string
update string
}
func main() {
resp, err := http.Get("http://www.oracle.com/technetwork/java/javase/downloads/index.html")
if err != nil {
fmt.Printf("Error on http Get: %v\n", err)
return
}
bodyb, err := ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Printf("QueriesForOwner: error in ReadAll: %v\n", err)
return
}
br := bytes.NewBuffer(bodyb)
jdkre, err := regexp.Compile(`h3[^\r\n]+(/technetwork/java/javase/downloads/(jdk(?:6|7)(?:u(\d+))?)-downloads-\d+\.html)`)
if err != nil {
fmt.Printf("extract: error in regexp compilation: %v\n", err)
return
}
jdks := jdkre.FindAllSubmatch(br.Bytes(), -1)
jdk7 := Jdk{string(jdks[0][4]), string(jdks[0][5]), string(jdks[0][6])}
jdk6 := Jdk{string(jdks[1][7]), string(jdks[1][8]), string(jdks[1][9])}
fmt.Printf("Jdk7: %v\nJdk6: %v\n", jdk7, jdk6)
jver, err := exec.Command("java", "-version").CombinedOutput()
if err != nil {
fmt.Printf("*ExitError from java -version:", err)
return
}
fmt.Println("JVer: '", string(jver), "'")
jverre, err := regexp.Compile(`1.(\d).\d(?:_(\d+))"`)
jvers := jverre.FindSubmatch(jver)
jj := string(jvers[0])
jv := string(jvers[1])
ju := string(jvers[2])
jdk := jdk6
if jv == "7" {
jdk = jdk7
}
if jdk.update != ju {
fmt.Println("Local JDK *NOT* up-to-date: you have ", jj, ", Oracle has ", jdk.Ver)
} else {
fmt.Println("Local JDK *up-to-date*: you have ", jj, ", equals to Oracle, which has", jdk.Ver)
}
}
Again, this is a crude script, oriented toward JDK, and you would need to adapt it to your specific need, making its output and exit status match what you need for your script.
On my (PC) workstation, it returns:
Jdk7: {/technetwork/java/javase/downloads/jdk7u9-downloads-1859576.html jdk7u9 9}
Jdk6: {/technetwork/java/javase/downloads/jdk6u37-downloads-1859587.html jdk6u37 37}
JVer: ' java version "1.6.0_31"
Java(TM) SE Runtime Environment (build 1.6.0_31-b05)
Java HotSpot(TM) Client VM (build 20.6-b01, mixed mode, sharing)
'
Local JDK *NOT* up-to-date: you have 1.6.0_31" , Oracle has jdk6u37
I don't know what information you are exactly looking for, but you can get some version information using
System.getProperty("java.version");
If this is not what you're looking for, check the other available properties here:
http://docs.oracle.com/javase/6/docs/api/java/lang/System.html#getProperties()
As for the latest available version, I guess you'd have to parse this site manually:
http://java.com/en/download/index.jsp
The latest version is on there, currently it's
Version 7 Update 9
You write that this is not what you want because "Oracle can change their website and styles". However, you want to find out the latest version of Java by accessing their service (website in this case). As long as you're not paying for this, they have no obligation to you, and can change the service whenever they want without your consent. And even when you're a paying customer, the best you can hope for is that they will inform you of upcoming changes, and your maintenance issues will remain.
Remember, it's THEIR service you want to use.
I have solved a similar issue some time ago with this groovy script (disclaimer: is somehow a "toy" script):
#Grapes([
#Grab(group='org.ccil.cowan.tagsoup', module='tagsoup', version='1.2.1')
])
def slurper = new XmlSlurper(new org.ccil.cowan.tagsoup.Parser())
def url = new URL("http://www.java.com/download/manual.jsp")
def html
url.withReader { reader ->
html = slurper.parse(reader)
}
def lastJava = html.body.div.div.div.strong.text()
println "Last available java version: ${lastJava}"
println "Currently installed java version: ${System.properties["java.version"]}"
It yields something like:
Last available java version:
Version 7 Update 9
Currently installed java version: 1.7.0_07
If you want to avoid maintenance issues due to changes to the page structure, maybe a better option is to search for a line containing "Version x Update y".
To get all system variables
Properties properties = System.getProperties();
System.out.println(properties);
Sample output, this might be different in your system depending on your OS and Java JDK/JRE version.
{
java.runtime.name = Java(TM) SE Runtime Environment,
sun.boot.library.path = C:\Program Files\Java\jdk1.8.0_31\jre\bin,
java.vm.version = 25.31-b07,
java.vm.vendor = Oracle Corporation,
java.vendor.url = http://java.oracle.com/,
path.separator = ;,
idea.launcher.port = 7534,
java.vm.name = Java HotSpot(TM) 64-Bit Server VM,
file.encoding.pkg = sun.io,
user.country = NP,
user.script = ,
sun.java.launcher = SUN_STANDARD,
sun.os.patch.level = ,
java.vm.specification.name = Java Virtual Machine Specification,
user.dir = C:\Users\...\roid,
java.runtime.version = 1.8.0_31-b13,
java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironment,
java.endorsed.dirs = C:\Program Files\Java\jdk1.8.0_31\jre\lib\endorsed,
os.arch = amd64,
java.io.tmpdir = C:\Windows\TEMP\,
line.separator = ,
java.vm.specification.vendor = Oracle Corporation,
user.variant = ,
os.name = Windows 8.1,
sun.jnu.encoding = Cp1252,
java.library.path = C:\Program...roid,
java.specification.name = Java Platform API Specification,
java.class.version = 52.0,
sun.management.compiler = HotSpot 64-Bit Tiered Compilers,
os.version = 6.3,
user.home = C:\Users\Xxx,
user.timezone = Asia/Kathmandu,
java.awt.printerjob = sun.awt.windows.WPrinterJob,
file.encoding = UTF-8,
idea.launcher.bin.path = C:\Program Files (x86)\xxx\bin,
java.specification.version = 1.8,
java.class.path = C:\Program Files\Java\jdk1.8.0_31\jre\lib\charsets.jar;...,
user.name = Xxx,
java.vm.specification.version = 1.8,
sun.java.command = com.xxxx.ameras,
java.home = C:\Program Files\Java\jdk1.8.0_31\jre,
sun.arch.data.model = 64,
user.language = en,
java.specification.vendor = Oracle Corporation,
awt.toolkit = sun.awt.windows.WToolkit,
java.vm.info = mixed mode,
java.version = 1.8.0_31,
java.ext.dirs = C:\Program Files\Java\jdk1.8.0_31\jre\lib\ext;...,
java.vendor = Oracle Corporation,
file.separator = \,
java.vendor.url.bug = http://bugreport.sun.com/bugreport/,
sun.io.unicode.encoding = UnicodeLittle,
sun.cpu.endian = little,
sun.desktop = windows,
sun.cpu.isalist = amd64
}
Retrive only specific variable
String javaVersion = System.getProperty("java.version");
System.out.println(javaVersion);
Output
1.8.0_31
#MarcelStör's solution no longer works - the version in the file is 1.8.0_51, while the actual latest version is 1.8.0_91/92. If you go to the Java test page in Firefox or Chrome and open the development console you can get the variable latest8Version which currently is 1.8.0_91. This could be wrapped in a Selenium/Firefox solution, but is an incredibly hacky way of getting this information.
System.getProperty("java.vm.specification.version");
System.getProperty("java.version");
If I execute set PATH=%PATH%;C:\\Something\\bin from the command line (cmd.exe) and then execute echo %PATH% I see this string added to the PATH. If I close and open the command line, that new string is not in PATH.
How can I update PATH permanently from the command line for all processes in the future, not just for the current process?
I don't want to do this by going to System Properties → Advanced → Environment variables and update PATH there.
This command must be executed from a Java application (please see my other question).
You can use:
setx PATH "%PATH%;C:\\Something\\bin"
However, setx will truncate the stored string to 1024 bytes, potentially corrupting the PATH.
/M will change the PATH in HKEY_LOCAL_MACHINE instead of HKEY_CURRENT_USER. In other words, a system variable, instead of the user's. For example:
SETX /M PATH "%PATH%;C:\your path with spaces"
You have to keep in mind, the new PATH is not visible in your current cmd.exe.
But if you look in the registry or on a new cmd.exe with "set p" you can see the new value.
The documentation on how to do this can be found on MSDN. The key extract is this:
To programmatically add or modify system environment variables, add them to the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment registry key, then broadcast a WM_SETTINGCHANGE message with lParam set to the string "Environment". This allows applications, such as the shell, to pick up your updates.
Note that your application will need elevated admin rights in order to be able to modify this key.
You indicate in the comments that you would be happy to modify just the per-user environment. Do this by editing the values in HKEY_CURRENT_USER\Environment. As before, make sure that you broadcast a WM_SETTINGCHANGE message.
You should be able to do this from your Java application easily enough using the JNI registry classes.
I caution against using the command
setx PATH "%PATH%;C:\Something\bin"
to modify the PATH variable because of a "feature" of its implementation. On many (most?) installations these days the variable will be lengthy - setx will truncate the stored string to 1024 bytes, potentially corrupting the PATH (see the discussion here).
(I signed up specifically to flag this issue, and so lack the site reputation to directly comment on the answer posted on May 2 '12. My thanks to beresfordt for adding such a comment)
This Python-script[*] does exactly that:
"""
Show/Modify/Append registry env-vars (ie `PATH`) and notify Windows-applications to pickup changes.
First attempts to show/modify HKEY_LOCAL_MACHINE (all users), and
if not accessible due to admin-rights missing, fails-back
to HKEY_CURRENT_USER.
Write and Delete operations do not proceed to user-tree if all-users succeed.
Syntax:
{prog} : Print all env-vars.
{prog} VARNAME : Print value for VARNAME.
{prog} VARNAME VALUE : Set VALUE for VARNAME.
{prog} +VARNAME VALUE : Append VALUE in VARNAME delimeted with ';' (i.e. used for `PATH`).
{prog} -VARNAME : Delete env-var value.
Note that the current command-window will not be affected,
changes would apply only for new command-windows.
"""
import winreg
import os, sys, win32gui, win32con
def reg_key(tree, path, varname):
return '%s\%s:%s' % (tree, path, varname)
def reg_entry(tree, path, varname, value):
return '%s=%s' % (reg_key(tree, path, varname), value)
def query_value(key, varname):
value, type_id = winreg.QueryValueEx(key, varname)
return value
def yield_all_entries(tree, path, key):
i = 0
while True:
try:
n,v,t = winreg.EnumValue(key, i)
yield reg_entry(tree, path, n, v)
i += 1
except OSError:
break ## Expected, this is how iteration ends.
def notify_windows(action, tree, path, varname, value):
win32gui.SendMessage(win32con.HWND_BROADCAST, win32con.WM_SETTINGCHANGE, 0, 'Environment')
print("---%s %s" % (action, reg_entry(tree, path, varname, value)), file=sys.stderr)
def manage_registry_env_vars(varname=None, value=None):
reg_keys = [
('HKEY_LOCAL_MACHINE', r'SYSTEM\CurrentControlSet\Control\Session Manager\Environment'),
('HKEY_CURRENT_USER', r'Environment'),
]
for (tree_name, path) in reg_keys:
tree = eval('winreg.%s'%tree_name)
try:
with winreg.ConnectRegistry(None, tree) as reg:
with winreg.OpenKey(reg, path, 0, winreg.KEY_ALL_ACCESS) as key:
if not varname:
for regent in yield_all_entries(tree_name, path, key):
print(regent)
else:
if not value:
if varname.startswith('-'):
varname = varname[1:]
value = query_value(key, varname)
winreg.DeleteValue(key, varname)
notify_windows("Deleted", tree_name, path, varname, value)
break ## Don't propagate into user-tree.
else:
value = query_value(key, varname)
print(reg_entry(tree_name, path, varname, value))
else:
if varname.startswith('+'):
varname = varname[1:]
value = query_value(key, varname) + ';' + value
winreg.SetValueEx(key, varname, 0, winreg.REG_EXPAND_SZ, value)
notify_windows("Updated", tree_name, path, varname, value)
break ## Don't propagate into user-tree.
except PermissionError as ex:
print("!!!Cannot access %s due to: %s" %
(reg_key(tree_name, path, varname), ex), file=sys.stderr)
except FileNotFoundError as ex:
print("!!!Cannot find %s due to: %s" %
(reg_key(tree_name, path, varname), ex), file=sys.stderr)
if __name__=='__main__':
args = sys.argv
argc = len(args)
if argc > 3:
print(__doc__.format(prog=args[0]), file=sys.stderr)
sys.exit()
manage_registry_env_vars(*args[1:])
Below are some usage examples, assuming it has been saved in a file called setenv.py somewhere in your current path.
Note that in these examples i didn't have admin-rights, so the changes affected only my local user's registry tree:
> REM ## Print all env-vars
> setenv.py
!!!Cannot access HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:PATH due to: [WinError 5] Access is denied
HKEY_CURRENT_USER\Environment:PATH=...
...
> REM ## Query env-var:
> setenv.py PATH C:\foo
!!!Cannot access HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:PATH due to: [WinError 5] Access is denied
!!!Cannot find HKEY_CURRENT_USER\Environment:PATH due to: [WinError 2] The system cannot find the file specified
> REM ## Set env-var:
> setenv.py PATH C:\foo
!!!Cannot access HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:PATH due to: [WinError 5] Access is denied
---Set HKEY_CURRENT_USER\Environment:PATH=C:\foo
> REM ## Append env-var:
> setenv.py +PATH D:\Bar
!!!Cannot access HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:PATH due to: [WinError 5] Access is denied
---Set HKEY_CURRENT_USER\Environment:PATH=C:\foo;D:\Bar
> REM ## Delete env-var:
> setenv.py -PATH
!!!Cannot access HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment:PATH due to: [WinError 5] Access is denied
---Deleted HKEY_CURRENT_USER\Environment:PATH
[*] Adapted from: http://code.activestate.com/recipes/416087-persistent-environment-variables-on-windows/
For reference purpose, for anyone searching how to change the path via code, I am quoting a useful post by a Delphi programmer from this web page: http://www.tek-tips.com/viewthread.cfm?qid=686382
TonHu (Programmer) 22 Oct 03 17:57 I found where I read the original
posting, it's here:
http://news.jrsoftware.org/news/innosetup.isx/msg02129....
The excerpt of what you would need is this:
You must specify the string "Environment" in LParam. In Delphi you'd
do it this way:
SendMessage(HWND_BROADCAST, WM_SETTINGCHANGE, 0, Integer(PChar('Environment')));
It was suggested by Jordan Russell, http://www.jrsoftware.org, the
author of (a.o.) InnoSetup, ("Inno Setup is a free installer for
Windows programs. First introduced in 1997, Inno Setup today rivals
and even surpasses many commercial installers in feature set and
stability.") (I just would like more people to use InnoSetup )
HTH
In a corporate network, where the user has only limited access and uses portable apps, there are these command line tricks:
Query the user env variables: reg query "HKEY_CURRENT_USER\Environment". Use "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" for LOCAL_MACHINE.
Add new user env variable: reg add "HKEY_CURRENT_USER\Environment" /v shared_dir /d "c:\shared" /t REG_SZ. Use REG_EXPAND_SZ for paths containing other %% variables.
Delete existing env variable: reg delete "HKEY_CURRENT_USER\Environment" /v shared_dir.
This script
http://www.autohotkey.com/board/topic/63210-modify-system-path-gui/
includes all the necessary Windows API calls which can be refactored for your needs. It is actually an AutoHotkey GUI to change the System PATH easily. Needs to be run as an Administrator.