Amri 25 Muhimu za Msingi za APT-GET na APT-CACHE kwa Usimamizi wa Kifurushi
Makala haya yanafafanua jinsi unavyoweza kujifunza kwa haraka kusakinisha, kuondoa, kusasisha na kutafuta vifurushi vya programu kwa kutumia apt-get na apt-cache amri kutoka kwa safu ya amri. Nakala hii inatoa amri muhimu ambazo zitakusaidia kushughulikia usimamizi wa kifurushi katika mifumo ya msingi ya Debian/Ubuntu.
Huduma ya apt-get ni programu yenye nguvu na ya bure ya usimamizi wa kifurushi, ambayo hutumiwa kufanya kazi na maktaba ya Ubuntu ya APT (Advanced Packaging Tool) kutekeleza usakinishaji wa vifurushi vipya vya programu, kuondoa vifurushi vya programu vilivyopo, uboreshaji wa vifurushi vya programu zilizopo na hata. kutumika kuboresha mfumo mzima wa uendeshaji.
Zana ya mstari wa amri ya apt-cache inatumika kutafuta akiba ya kifurushi cha programu inayofaa. Kwa maneno rahisi, chombo hiki kinatumika kutafuta vifurushi vya programu, kukusanya taarifa za vifurushi na pia kutumika kutafuta ni vifurushi vinavyopatikana tayari kwa usakinishaji kwenye mifumo ya msingi ya Debian au Ubuntu.
1. Je, Ninawezaje Kuorodhesha Vifurushi Vyote Vinavyopatikana?
Ili kuorodhesha vifurushi vyote vinavyopatikana, chapa amri ifuatayo.
$ apt-cache pkgnames
esseract-ocr-epo pipenightdreams mumudvb tbb-examples libsvm-java libmrpt-hmtslam0.9 libboost-timer1.50-dev kcm-touchpad g++-4.5-multilib ...
2. Je! Nitajuaje Jina la Kifurushi na Maelezo ya Programu?
Ili kujua jina la kifurushi na maelezo yake kabla ya kusakinisha, tumia bendera ya 'tafuta'. Kutumia tafuta na apt-cache kutaonyesha orodha ya vifurushi vinavyolingana na maelezo mafupi. Wacha tuseme ungependa kujua maelezo ya kifurushi 'vsftpd', basi amri itakuwa.
$ apt-cache search vsftpd
vsftpd - lightweight, efficient FTP server written for security ccze - A robust, modular log coloriser ftpd - File Transfer Protocol (FTP) server yasat - simple stupid audit tool
Ili kupata na kuorodhesha vifurushi vyote vinavyoanza na 'vsftpd', unaweza kutumia amri ifuatayo.
$ apt-cache pkgnames vsftpd
vsttpd
3. Je, Nitaangaliaje Taarifa za Kifurushi?
Kwa mfano, ikiwa ungependa kuangalia habari ya kifurushi pamoja na maelezo mafupi sema (nambari ya toleo, angalia hesabu, saizi, saizi iliyosakinishwa, kitengo n.k). Tumia amri ndogo ya 'onyesha' kama inavyoonyeshwa hapa chini.
$ apt-cache show netcat
Package: netcat Priority: optional Section: universe/net Installed-Size: 30 Maintainer: Ubuntu Developers <[email > Original-Maintainer: Ruben Molina <[email > Architecture: all Version: 1.10-40 Depends: netcat-traditional (>= 1.10-39) Filename: pool/universe/n/netcat/netcat_1.10-40_all.deb Size: 3340 MD5sum: 37c303f02b260481fa4fc9fb8b2c1004 SHA1: 0371a3950d6967480985aa014fbb6fb898bcea3a SHA256: eeecb4c93f03f455d2c3f57b0a1e83b54dbeced0918ae563784e86a37bcc16c9 Description-en: TCP/IP swiss army knife -- transitional package This is a "dummy" package that depends on lenny's default version of netcat, to ease upgrades. It may be safely removed. Description-md5: 1353f8c1d079348417c2180319bdde09 Bugs: https://bugs.launchpad.net/ubuntu/+filebug Origin: Ubuntu
4. Je, Nitaangaliaje Vitegemezi vya Vifurushi Maalum?
Tumia amri ndogo ya 'showpkg' kuangalia utegemezi wa vifurushi fulani vya programu. ikiwa vifurushi hivyo vya utegemezi vimewekwa au la. Kwa mfano, tumia amri ya 'showpkg' pamoja na jina la kifurushi.
$ apt-cache showpkg vsftpd
Package: vsftpd
Versions:
2.3.5-3ubuntu1 (/var/lib/apt/lists/in.archive.ubuntu.com_ubuntu_dists_quantal_main_binary-i386_Packages)
Description Language:
File: /var/lib/apt/lists/in.archive.ubuntu.com_ubuntu_dists_quantal_main_binary-i386_Packages
MD5: 81386f72ac91a5ea48f8db0b023f3f9b
Description Language: en
File: /var/lib/apt/lists/in.archive.ubuntu.com_ubuntu_dists_quantal_main_i18n_Translation-en
MD5: 81386f72ac91a5ea48f8db0b023f3f9b
Reverse Depends:
ubumirror,vsftpd
harden-servers,vsftpd
Dependencies:
2.3.5-3ubuntu1 - debconf (18 0.5) debconf-2.0 (0 (null)) upstart-job (0 (null)) libc6 (2 2.15) libcap2 (2 2.10) libpam0g (2 0.99.7.1) libssl1.0.0 (2 1.0.0) libwrap0 (2 7.6-4~) adduser (0 (null)) libpam-modules (0 (null)) netbase (0 (null)) logrotate (0 (null)) ftp-server (0 (null)) ftp-server (0 (null))
Provides:
2.3.5-3ubuntu1 - ftp-server
Reverse Provides:5. Je, Nitaangaliaje takwimu za Akiba
Amri ndogo ya 'takwimu' itaonyesha takwimu za jumla kuhusu kache. Kwa mfano, amri ifuatayo itaonyesha Jumla ya majina ya vifurushi ni idadi ya vifurushi vilivyopatikana kwenye kashe.
$ apt-cache stats
Total package names: 51868 (1,037 k) Total package structures: 51868 (2,490 k) Normal packages: 39505 Pure virtual packages: 602 Single virtual packages: 3819 Mixed virtual packages: 1052 Missing: 6890 Total distinct versions: 43015 (2,753 k) Total distinct descriptions: 81048 (1,945 k) Total dependencies: 252299 (7,064 k) Total ver/file relations: 45567 (729 k) Total Desc/File relations: 81048 (1,297 k) Total Provides mappings: 8228 (165 k) Total globbed strings: 286 (3,518 ) Total dependency version space: 1,145 k Total slack space: 62.6 k Total space accounted for: 13.3 M
6. Jinsi ya Kusasisha Vifurushi vya Mfumo
Amri ya ‘sasisha’ inatumika kusawazisha upya faili za faharasa za kifurushi kutoka kwa vyanzo vyake vilivyoainishwa katika faili ya /etc/apt/sources.list. Amri ya sasisho ilichukua vifurushi kutoka kwa maeneo yao na kusasisha vifurushi hadi toleo jipya zaidi.
$ sudo apt-get update
[sudo] password for tecmint: Ign http://security.ubuntu.com quantal-security InRelease Get:1 http://security.ubuntu.com quantal-security Release.gpg [933 B] Get:2 http://security.ubuntu.com quantal-security Release [49.6 kB] Ign http://in.archive.ubuntu.com quantal InRelease Ign http://in.archive.ubuntu.com quantal-updates InRelease Get:3 http://repo.varnish-cache.org precise InRelease [13.7 kB] Ign http://in.archive.ubuntu.com quantal-backports InRelease Hit http://in.archive.ubuntu.com quantal Release.gpg Get:4 http://security.ubuntu.com quantal-security/main Sources [34.8 kB] Get:5 http://in.archive.ubuntu.com quantal-updates Release.gpg [933 B] ...
7. Jinsi ya Kuboresha Vifurushi vya Programu
Amri ya 'sasisha' inatumika kuboresha vifurushi vyote vya programu vilivyosakinishwa kwenye mfumo. Chini ya hali yoyote vifurushi vilivyosakinishwa kwa sasa haviondolewi au vifurushi ambavyo havijasakinishwa wala kurejeshwa na kusakinishwa ili kukidhi utegemezi wa uboreshaji.
$ sudo apt-get upgrade
Reading package lists... Done Building dependency tree Reading state information... Done The following packages have been kept back: linux-headers-generic linux-image-generic wine1.5 wine1.5-i386 The following packages will be upgraded: activity-log-manager-common activity-log-manager-control-center adium-theme-ubuntu alacarte alsa-base app-install-data-partner appmenu-gtk appmenu-gtk3 apport apport-gtk apt apt-transport-https apt-utils aptdaemon aptdaemon-data at-spi2-core bamfdaemon base-files bind9-host ...
Hata hivyo, ikiwa unataka kuboresha, bila kujali kama vifurushi vya programu vitaongezwa au kuondolewa ili kutimiza utegemezi, tumia amri ndogo ya 'dist-upgrade'.
$ sudo apt-get dist-upgrade
8. Je, ninawezaje Kusakinisha au Kuboresha Vifurushi Maalum?
Amri ndogo ya 'sakinisha' inafuatiliwa na kifurushi kimoja au zaidi unataka usakinishaji au uboreshaji.
$ sudo apt-get install netcat
Reading package lists... Done Building dependency tree Reading state information... Done The following extra packages will be installed: netcat-traditional The following NEW packages will be installed: netcat netcat-traditional 0 upgraded, 2 newly installed, 0 to remove and 328 not upgraded. Need to get 67.1 kB of archives. After this operation, 186 kB of additional disk space will be used. Do you want to continue [Y/n]? y Get:1 http://in.archive.ubuntu.com/ubuntu/ quantal/universe netcat-traditional i386 1.10-40 [63.8 kB] Get:2 http://in.archive.ubuntu.com/ubuntu/ quantal/universe netcat all 1.10-40 [3,340 B] Fetched 67.1 kB in 1s (37.5 kB/s) Selecting previously unselected package netcat-traditional. (Reading database ... 216118 files and directories currently installed.) Unpacking netcat-traditional (from .../netcat-traditional_1.10-40_i386.deb) ... Selecting previously unselected package netcat. Unpacking netcat (from .../netcat_1.10-40_all.deb) ... Processing triggers for man-db ... Setting up netcat-traditional (1.10-40) ... Setting up netcat (1.10-40) ...
9. Ninawezaje Kusakinisha Vifurushi Vingi?
Unaweza kuongeza zaidi ya jina la kifurushi kimoja pamoja na amri ili kusakinisha vifurushi vingi kwa wakati mmoja. Kwa mfano, amri ifuatayo itasakinisha vifurushi 'goaccess'.
$ sudo apt-get install nethogs goaccess
Reading package lists... Done Building dependency tree Reading state information... Done goaccess is already the newest version. nethogs is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 328 not upgraded.
10. Jinsi ya Kusakinisha Vifurushi Kadhaa kwa kutumia Wildcard
Kwa msaada wa kujieleza mara kwa mara unaweza kuongeza vifurushi kadhaa na kamba moja. Kwa mfano, tunatumia * wildcard kusakinisha vifurushi kadhaa ambavyo vina mfuatano wa ‘*name*‘, jina litakuwa ‘jina la kifurushi’.
$ sudo apt-get install '*name*'
11. Jinsi ya kusakinisha Vifurushi bila Kuboresha
Kutumia amri ndogo ya '-no-upgrade' kutazuia vifurushi vilivyosakinishwa tayari kusasishwa.
$ sudo apt-get install packageName --no-upgrade
Reading package lists... Done Building dependency tree Reading state information... Done Skipping vsftpd, it is already installed and upgrade is not set. 0 upgraded, 0 newly installed, 0 to remove and 328 not upgraded.
12. Jinsi ya Kuboresha Vifurushi Maalum pekee
Amri ya ‘–only-upgrade‘ haisakinishi vifurushi vipya bali inaboresha tu vifurushi vilivyosakinishwa na kulemaza usakinishaji mpya wa vifurushi.
$ sudo apt-get install packageName --only-upgrade
Reading package lists... Done Building dependency tree Reading state information... Done vsftpd is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 328 not upgraded.
13. Je, nitasakinishaje Toleo Maalum la Kifurushi?
Wacha tuseme ungependa kusakinisha toleo maalum la vifurushi, tumia tu ‘=’ na jina la kifurushi na uongeze toleo unalotaka.
$ sudo apt-get install vsftpd=2.3.5-3ubuntu1
Reading package lists... Done Building dependency tree Reading state information... Done vsftpd is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 328 not upgraded.
14. Je, Nitaondoaje Vifurushi Bila Usanidi
Kuondoa vifurushi vya programu bila kuondoa faili zao za usanidi (kwa kutumia tena usanidi sawa baadaye). Tumia amri ya 'ondoa' kama inavyoonyeshwa.
$ sudo apt-get remove vsftpd
[sudo] password for tecmint: Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: vsftpd 0 upgraded, 0 newly installed, 1 to remove and 328 not upgraded. After this operation, 364 kB disk space will be freed. Do you want to continue [Y/n]? y (Reading database ... 216156 files and directories currently installed.) Removing vsftpd ... vsftpd stop/waiting Processing triggers for ureadahead ... Processing triggers for man-db ...
15. Je, Ninawezaje Kuondoa Vifurushi Kabisa
Ili kuondoa vifurushi vya programu ikijumuisha faili zao za usanidi, tumia amri ndogo ya 'purge' kama inavyoonyeshwa hapa chini.
$ sudo apt-get purge vsftpd
Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: vsftpd* 0 upgraded, 0 newly installed, 1 to remove and 328 not upgraded. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 216107 files and directories currently installed.) Removing vsftpd ... Purging configuration files for vsftpd ... Processing triggers for ureadahead ...
Vinginevyo, unaweza kuchanganya amri zote mbili pamoja kama inavyoonyeshwa hapa chini.
$ sudo apt-get remove --purge vsftpd
Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: vsftpd* 0 upgraded, 0 newly installed, 1 to remove and 328 not upgraded. After this operation, 364 kB disk space will be freed. Do you want to continue [Y/n]? y (Reading database ... 216156 files and directories currently installed.) Removing vsftpd ... vsftpd stop/waiting Purging configuration files for vsftpd ... Processing triggers for ureadahead ... Processing triggers for man-db ...
16. Ninawezaje Kusafisha Nafasi ya Diski
Amri ya 'safisha' inatumiwa kuweka nafasi ya diski kwa kusafisha (zilizopakuliwa) faili za .deb (furushi) kutoka kwa hazina ya ndani.
$ sudo apt-get clean
17. Ninawezaje Kupakua Msimbo wa Chanzo Pekee wa Kifurushi
Ili kupakua msimbo wa chanzo pekee wa kifurushi fulani, tumia chaguo ‘-pakua-pekee chanzo’ na ‘jina la kifurushi’ kama inavyoonyeshwa.
$ sudo apt-get --download-only source vsftpd
Reading package lists... Done Building dependency tree Reading state information... Done Need to get 220 kB of source archives. Get:1 http://in.archive.ubuntu.com/ubuntu/ quantal/main vsftpd 2.3.5-3ubuntu1 (dsc) [1,883 B] Get:2 http://in.archive.ubuntu.com/ubuntu/ quantal/main vsftpd 2.3.5-3ubuntu1 (tar) [188 kB] Get:3 http://in.archive.ubuntu.com/ubuntu/ quantal/main vsftpd 2.3.5-3ubuntu1 (diff) [30.5 kB] Fetched 220 kB in 4s (49.1 kB/s) Download complete and in download only mode
18. Ninawezaje Kupakua na Kufungua Kifurushi
Ili kupakua na kufungua msimbo wa chanzo wa kifurushi kwenye saraka maalum, chapa amri ifuatayo.
$ sudo apt-get source vsftpd
Reading package lists... Done Building dependency tree Reading state information... Done Need to get 220 kB of source archives. Get:1 http://in.archive.ubuntu.com/ubuntu/ quantal/main vsftpd 2.3.5-3ubuntu1 (dsc) [1,883 B] Get:2 http://in.archive.ubuntu.com/ubuntu/ quantal/main vsftpd 2.3.5-3ubuntu1 (tar) [188 kB] Get:3 http://in.archive.ubuntu.com/ubuntu/ quantal/main vsftpd 2.3.5-3ubuntu1 (diff) [30.5 kB] Fetched 220 kB in 1s (112 kB/s) gpgv: Signature made Thursday 24 May 2012 02:35:09 AM IST using RSA key ID 2C48EE4E gpgv: Can't check signature: public key not found dpkg-source: warning: failed to verify signature on ./vsftpd_2.3.5-3ubuntu1.dsc dpkg-source: info: extracting vsftpd in vsftpd-2.3.5 dpkg-source: info: unpacking vsftpd_2.3.5.orig.tar.gz dpkg-source: info: unpacking vsftpd_2.3.5-3ubuntu1.debian.tar.gz dpkg-source: info: applying 01-builddefs.patch dpkg-source: info: applying 02-config.patch dpkg-source: info: applying 03-db-doc.patch dpkg-source: info: applying 04-link-local.patch dpkg-source: info: applying 05-whitespaces.patch dpkg-source: info: applying 06-greedy.patch dpkg-source: info: applying 07-utf8.patch dpkg-source: info: applying 08-manpage.patch dpkg-source: info: applying 09-s390.patch dpkg-source: info: applying 10-remote-dos.patch dpkg-source: info: applying 11-alpha.patch dpkg-source: info: applying 09-disable-anonymous.patch dpkg-source: info: applying 12-ubuntu-use-snakeoil-ssl.patch
19. Ninawezaje Kupakua, Kufungua na Kukusanya Kifurushi
Unaweza pia kupakua, kufungua na kukusanya msimbo wa chanzo kwa wakati mmoja, kwa kutumia chaguo ‘–kusanya’ kama inavyoonyeshwa hapa chini.
$ sudo apt-get --compile source goaccess
[sudo] password for tecmint: Reading package lists... Done Building dependency tree Reading state information... Done Need to get 130 kB of source archives. Get:1 http://in.archive.ubuntu.com/ubuntu/ quantal/universe goaccess 1:0.5-1 (dsc) [1,120 B] Get:2 http://in.archive.ubuntu.com/ubuntu/ quantal/universe goaccess 1:0.5-1 (tar) [127 kB] Get:3 http://in.archive.ubuntu.com/ubuntu/ quantal/universe goaccess 1:0.5-1 (diff) [2,075 B] Fetched 130 kB in 1s (68.0 kB/s) gpgv: Signature made Tuesday 26 June 2012 09:38:24 AM IST using DSA key ID A9FD4821 gpgv: Can't check signature: public key not found dpkg-source: warning: failed to verify signature on ./goaccess_0.5-1.dsc dpkg-source: info: extracting goaccess in goaccess-0.5 dpkg-source: info: unpacking goaccess_0.5.orig.tar.gz dpkg-source: info: unpacking goaccess_0.5-1.debian.tar.gz dpkg-buildpackage: source package goaccess dpkg-buildpackage: source version 1:0.5-1 dpkg-buildpackage: source changed by Chris Taylor <[email > dpkg-buildpackage: host architecture i386 dpkg-source --before-build goaccess-0.5 dpkg-checkbuilddeps: Unmet build dependencies: debhelper (>= 9) autotools-dev libncurses5-dev libglib2.0-dev libgeoip-dev autoconf dpkg-buildpackage: warning: build dependencies/conflicts unsatisfied; aborting dpkg-buildpackage: warning: (Use -d flag to override.) ...
20. Ninawezaje Kupakua Kifurushi Bila Kusakinisha
Kwa kutumia chaguo la 'kupakua', unaweza kupakua kifurushi chochote bila kukisakinisha. Kwa mfano, amri ifuatayo itapakua tu kifurushi cha 'nethogs' kwenye saraka ya sasa ya kufanya kazi.
$ sudo apt-get download nethogs
Get:1 Downloading nethogs 0.8.0-1 [27.1 kB] Fetched 27.1 kB in 3s (7,506 B/s)
21. Je, Nitaangaliaje Mabadiliko ya Logi ya Kifurushi?
Alama ya 'changelog' hupakua kumbukumbu ya mabadiliko ya kifurushi na inaonyesha toleo la kifurushi ambalo limesakinishwa.
$ sudo apt-get changelog vsftpd
vsftpd (2.3.5-3ubuntu1) quantal; urgency=low
* Merge from Debian testing (LP: #1003644). Remaining changes:
+ debian/vsftpd.upstart: migrate vsftpd to upstart.
+ Add apport hook (LP: #513978):
- debian/vsftpd.apport: Added.
- debian/control: Build-depends on dh-apport.
- debian/rules: Add --with apport.
+ Add debian/watch file.
+ debian/patches/09-disable-anonymous.patch: Disable anonymous login
by default. (LP: #528860)
* debian/patches/12-ubuntu-us-snakeoil-ssl.patch: Use snakeoil SSL
certificates and key.
-- Andres Rodriguez <[email > Wed, 23 May 2012 16:59:36 -0400
...22. Je, Nitaangaliaje Vitegemezi Vilivyovunjika?
Amri ya 'cheki' ni zana ya utambuzi. Ilitumika kusasisha kashe ya kifurushi na hundi ya utegemezi uliovunjika.
$ sudo apt-get check
[sudo] password for tecmint: Reading package lists... Done Building dependency tree Reading state information... Done
23. Je, Nitatafutaje na Kujenga Vitegemezi?
Amri hii ya 'build-dep' hutafuta hazina za ndani kwenye mfumo na kusakinisha vitegemezi vya ujenzi kwa kifurushi. Ikiwa kifurushi hakipo kwenye hazina ya ndani kitarudisha msimbo wa makosa.
$ sudo apt-get build-dep netcat
The following NEW packages will be installed: debhelper dh-apparmor html2text po-debconf quilt 0 upgraded, 5 newly installed, 0 to remove and 328 not upgraded. Need to get 1,219 kB of archives. After this operation, 2,592 kB of additional disk space will be used. Do you want to continue [Y/n]? y Get:1 http://in.archive.ubuntu.com/ubuntu/ quantal/main html2text i386 1.3.2a-15build1 [91.4 kB] Get:2 http://in.archive.ubuntu.com/ubuntu/ quantal/main po-debconf all 1.0.16+nmu2ubuntu1 [210 kB] Get:3 http://in.archive.ubuntu.com/ubuntu/ quantal/main dh-apparmor all 2.8.0-0ubuntu5 [9,846 B] Get:4 http://in.archive.ubuntu.com/ubuntu/ quantal/main debhelper all 9.20120608ubuntu1 [623 kB] Get:5 http://in.archive.ubuntu.com/ubuntu/ quantal/main quilt all 0.60-2 [285 kB] Fetched 1,219 kB in 4s (285 kB/s) ...
24. Ninawezaje Kusafisha Kiotomatiki Apt-Get Cache?
Amri ya 'autoclean' hufuta faili zote za .deb kutoka /var/cache/apt/archives ili kutoa kiasi kikubwa cha nafasi ya diski.
$ sudo apt-get autoclean
Reading package lists... Done Building dependency tree Reading state information... Done
25. Ninawezaje Kuondoa Vifurushi Vilivyosakinishwa Kiotomatiki?
Amri ndogo ya 'autoremove' inatumika kuondoa vifurushi kiotomatiki ambavyo hakika vilisakinishwa kutosheleza utegemezi wa vifurushi vingine na lakini sasa havihitajiki tena. Kwa mfano, amri ifuatayo itaondoa kifurushi kilichosanikishwa na utegemezi wake.
$ sudo apt-get autoremove vsftpd
Reading package lists... Done Building dependency tree Reading state information... Done Package 'vsftpd' is not installed, so not removed 0 upgraded, 0 newly installed, 0 to remove and 328 not upgraded.
Nimeshughulikia chaguzi nyingi zinazopatikana na apt-get na apt-cache amri, lakini bado kuna chaguzi zaidi zinazopatikana, unaweza kuziangalia kwa kutumia 'man apt-get' au 'man apt-cache' kutoka kwa terminal. Natumai umefurahiya kusoma nakala hii, Ikiwa nimekosa chochote na ungependa niongeze kwenye orodha. Tafadhali jisikie huru kutaja katika maoni hapa chini.
Soma Pia : Amri 20 Muhimu za Linux YUM kwa Usimamizi wa Kifurushi