{"id":705,"date":"2020-01-12T02:30:53","date_gmt":"2020-01-12T02:30:53","guid":{"rendered":"http:\/\/www.recologypower.com:9080\/?p=705"},"modified":"2020-01-12T02:30:54","modified_gmt":"2020-01-12T02:30:54","slug":"linuxdd%e5%91%bd%e4%bb%a4%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"http:\/\/www.recologypower.com:9080\/?p=705","title":{"rendered":"[Linux]dd\u547d\u4ee4\u8be6\u89e3"},"content":{"rendered":"\n<p> d \u662f Linux\/UNIX \u4e0b\u7684\u4e00\u4e2a\u975e\u5e38\u6709\u7528\u7684\u547d\u4ee4\uff0c\u4f5c\u7528\u662f\u7528\u6307\u5b9a\u5927\u5c0f\u7684\u5757\u62f7\u8d1d\u4e00\u4e2a\u6587\u4ef6\uff0c\u5e76\u5728\u62f7\u8d1d\u7684\u540c\u65f6\u8fdb\u884c\u6307\u5b9a\u7684\u8f6c\u6362\u3002<br>\u540d\u79f0: dd<br>\u4f7f\u7528\u6743\u9650: \u6240\u6709\u4f7f\u7528\u8005dd \u8fd9\u4e2a\u6307\u4ee4\u5728 manual \u91cc\u7684\u5b9a\u4e49\u662f convert and copy a file<br>\u4f7f\u7528\u65b9\u5f0f:<br>dd [option]<br>\u5982\u679c\u4f60\u60f3\u8981\u5728\u7ebf\u770b manual, \u53ef\u4ee5\u8bd5\u8bd5: <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>dd \u2013help<\/code><\/pre>\n\n\n\n<p> \u6216\u662f <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>info dd<\/code><\/pre>\n\n\n\n<p> \u5982\u679c\u4f60\u60f3\u8981\u770b\u770b\u8fd9\u4e2a\u7248\u672c\u5982\u4f55: <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>dd \u2013version<\/code><\/pre>\n\n\n\n<p> \u8f93\u5165\u6216\u8f93\u51fa <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>dd if=[STDIN] of=[STDOUT]<\/code><\/pre>\n\n\n\n<p> \u5f3a\u8feb\u8f93\u5165\u6216\u8f93\u51fa\u7684Size\u4e3a\u591a\u5c11Bytes <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>bs: dd -ibs=[BYTE] -obs=[SIZE]<\/code><\/pre>\n\n\n\n<p> \u5f3a\u8feb\u4e00\u6b21\u53ea\u505a\u591a\u5c11\u4e2a Bytes <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>cbs=BYTES<\/code><\/pre>\n\n\n\n<p> \u8df3\u8fc7\u4e00\u6bb5\u4ee5\u540e\u624d\u8f93\u51fa <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>seek=BLOCKS<\/code><\/pre>\n\n\n\n<p> \u8df3\u8fc7\u4e00\u6bb5\u4ee5\u540e\u624d\u8f93\u5165 <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>skip=BLOCKS<\/code><\/pre>\n\n\n\n<ul><li>\u8bed\u6cd5\uff1add [\u9009\u9879]<\/li><li>if =\u8f93\u5165\u6587\u4ef6\uff08\u6216\u8bbe\u5907\u540d\u79f0\uff09\u3002<\/li><li>of =\u8f93\u51fa\u6587\u4ef6\uff08\u6216\u8bbe\u5907\u540d\u79f0\uff09\u3002<\/li><li>ibs = bytes \u4e00\u6b21\u8bfb\u53d6bytes\u5b57\u8282\uff0c\u5373\u8bfb\u5165\u7f13\u51b2\u533a\u7684\u5b57\u8282\u6570\u3002<\/li><li>skip = blocks \u8df3\u8fc7\u8bfb\u5165\u7f13\u51b2\u533a\u5f00\u5934\u7684ibs*blocks\u5757\u3002<\/li><li>obs = bytes \u4e00\u6b21\u5199\u5165bytes\u5b57\u8282\uff0c\u5373\u5199\u5165\u7f13\u51b2\u533a\u7684\u5b57\u8282\u6570\u3002<\/li><li>bs = bytes \u540c\u65f6\u8bbe\u7f6e\u8bfb\/\u5199\u7f13\u51b2\u533a\u7684\u5b57\u8282\u6570\uff08\u7b49\u4e8e\u8bbe\u7f6eibs\u548cobs\uff09\u3002<\/li><li>cbs = byte \u4e00\u6b21\u8f6c\u6362bytes\u5b57\u8282\u3002<\/li><li>count=blocks \u53ea\u62f7\u8d1d\u8f93\u5165\u7684blocks\u5757\u3002<\/li><li>conv = ASCII \u628aEBCDIC\u7801\u8f6c\u6362\u4e3aASCIl\u7801\u3002<\/li><li>conv = ebcdic \u628aASCIl\u7801\u8f6c\u6362\u4e3aEBCDIC\u7801\u3002<\/li><li>conv = ibm \u628aASCIl\u7801\u8f6c\u6362\u4e3aalternate EBCDIC\u7801\u3002<\/li><li>conv = block \u628a\u53d8\u52a8\u4f4d\u8f6c\u6362\u6210\u56fa\u5b9a\u5b57\u7b26\u3002<\/li><li>conv = ublock \u628a\u56fa\u5b9a\u4f4d\u8f6c\u6362\u6210\u53d8\u52a8\u4f4d\u3002<\/li><li>conv = ucase \u628a\u5b57\u6bcd\u7531\u5c0f\u5199\u8f6c\u6362\u4e3a\u5927\u5199\u3002<\/li><li>conv = lcase \u628a\u5b57\u6bcd\u7531\u5927\u5199\u8f6c\u6362\u4e3a\u5c0f\u5199\u3002<\/li><li>conv = notrunc \u4e0d\u622a\u77ed\u8f93\u51fa\u6587\u4ef6\u3002<\/li><li>conv = swab \u4ea4\u6362\u6bcf\u4e00\u5bf9\u8f93\u5165\u5b57\u8282\u3002<\/li><li>conv = noerror \u51fa\u9519\u65f6\u4e0d\u505c\u6b62\u5904\u7406\u3002<\/li><li>conv = sync \u628a\u6bcf\u4e2a\u8f93\u5165\u8bb0\u5f55\u7684\u5927\u5c0f\u90fd\u8c03\u5230ibs\u7684\u5927\u5c0f\uff08\u7528NUL\u586b\u5145\uff09\u3002<\/li><\/ul>\n\n\n\n<p> \u4f8b1\uff1a\u8981\u628a\u4e00\u5f20\u8f6f\u76d8\u7684\u5185\u5bb9\u62f7\u8d1d\u5230\u53e6\u4e00\u5f20\u8f6f\u76d8\u4e0a\uff0c\u5229\u7528\/tmp\u4f5c\u4e3a\u4e34\u65f6\u5b58\u50a8\u533a\u3002\u628a\u6e90\u76d8\u63d2\u5165\u9a71\u52a8\u5668\u4e2d\uff0c\u8f93\u5165\u4e0b\u8ff0\u547d\u4ee4\uff1a <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>$ dd if =\/dev\/fd0 of = \/tmp\/tmpfile<\/code><\/pre>\n\n\n\n<p> \u62f7\u8d1d\u5b8c\u6210\u540e\uff0c\u5c06\u6e90\u76d8\u4ece\u9a71\u52a8\u5668\u4e2d\u53d6\u51fa\uff0c\u628a\u76ee\u6807\u76d8\u63d2\u5165\uff0c\u8f93\u5165\u547d\u4ee4\uff1a <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>$ dd if = \/tmp\/tmpfile of =\/dev\/fd0<\/code><\/pre>\n\n\n\n<p> \u8f6f\u76d8\u62f7\u8d1d\u5b8c\u6210\u540e\uff0c\u5e94\u8be5\u5c06\u4e34\u65f6\u6587\u4ef6\u5220\u9664\uff1a <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>$ rm \/tmp\/tmpfile<\/code><\/pre>\n\n\n\n<p> \u4f8b2\uff1a\u628anet.i\u8fd9\u4e2a\u6587\u4ef6\u5199\u5165\u8f6f\u76d8\u4e2d\uff0c\u5e76\u8bbe\u5b9a\u8bfb\/\u5199\u7f13\u51b2\u533a\u7684\u6570\u76ee\u3002<br>\uff08\u6ce8\u610f\uff1a\u8f6f\u76d8\u4e2d\u7684\u5185\u5bb9\u4f1a\u88ab\u5b8c\u5168\u8986\u76d6\u6389\uff09 <\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">$ dd if = net.i of = \/dev\/fd0 bs = 16384<\/pre>\n\n\n\n<p> \u4f8b3\uff1a\u5c06\u6587\u4ef6sfile\u62f7\u8d1d\u5230\u6587\u4ef6 dfile\u4e2d\u3002 <\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">$ dd if=sfile of=dfile<\/pre>\n\n\n\n<p> \u4f8b4\uff1a\u521b\u5efa\u4e00\u4e2a100M\u7684\u7a7a\u6587\u4ef6 <\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">dd if=\/dev\/zero of=hello.txt bs=100M count=1<\/pre>\n\n\n\n<ul><li>============================================<\/li><li>\/dev\/null\uff0c\u5916\u53f7\u53eb\u65e0\u5e95\u6d1e\uff0c\u4f60\u53ef\u4ee5\u5411\u5b83\u8f93\u51fa\u4efb\u4f55\u6570\u636e\uff0c\u5b83\u901a\u5403\uff0c\u5e76\u4e14\u4e0d\u4f1a\u6491\u7740\uff01<\/li><li>\/dev\/zero,\u662f\u4e00\u4e2a\u8f93\u5165\u8bbe\u5907\uff0c\u4f60\u53ef\u4f60\u7528\u5b83\u6765\u521d\u59cb\u5316\u6587\u4ef6\u3002<\/li><li>\/dev\/null\u2014\u2014\u5b83\u662f\u7a7a\u8bbe\u5907\uff0c\u4e5f\u79f0\u4e3a\u4f4d\u6876\uff08bit bucket\uff09\u3002\u4efb\u4f55\u5199\u5165\u5b83\u7684\u8f93\u51fa\u90fd\u4f1a\u88ab\u629b\u5f03\u3002\u5982\u679c\u4e0d\u60f3\u8ba9\u6d88\u606f\u4ee5\u6807\u51c6\u8f93\u51fa\u663e\u793a\u6216\u5199\u5165\u6587\u4ef6\uff0c\u90a3\u4e48\u53ef\u4ee5\u5c06\u6d88\u606f\u91cd\u5b9a\u5411\u5230\u4f4d\u6876\u3002<\/li><li>\/dev\/zero\u2014\u2014\u8be5\u8bbe\u5907\u65e0\u7a77\u5c3d\u5730\u63d0\u4f9b0\uff0c\u53ef\u4ee5\u4f7f\u7528\u4efb\u4f55\u4f60\u9700\u8981\u7684\u6570\u76ee\u2014\u2014\u8bbe\u5907\u63d0\u4f9b\u7684\u8981\u591a\u7684\u591a\u3002\u4ed6\u53ef\u4ee5\u7528\u4e8e\u5411\u8bbe\u5907\u6216\u6587\u4ef6\u5199\u5165\u5b57\u7b26\u4e320\u3002<\/li><\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>$ dd if=\/dev\/zero of=.\/test.txt bs=1k count=1\n$ ls -l\ntotal 4\n-rw-r\u2013r\u2013 1 oracle dba 1024 Jul 15 16:56 test.txt<\/code><\/pre>\n\n\n\n<p> eg: <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>$ find \/ -name access_log 2>\/dev\/null<\/code><\/pre>\n\n\n\n<p> \u521b\u5efa\u7279\u5b9a\u5927\u5c0f\u6587\u4ef6\u6700\u7b80\u5355\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 dd \u547d\u4ee4\u3002 <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>dd if=\u201cinputFileName\u201d of=\u201doutFileName\u201d bs=\u201d\u5757\u5927\u5c0f\u201d count=\u201c\u5757\u4e2a\u6570\u201d<\/code><\/pre>\n\n\n\n<p>\n\u5757\u5927\u5c0f\u53ef\u4ee5\u4f7f\u7528\u5404\u79cd\u8ba1\u91cf\u5355\u4f4d<br>\u5b57\u8282(1B) \u2013 c \u5b57(2B) \u2013 w<br>\u5757(512B) \u2013 b \u5343\u5b57\u8282(1024B) \u2013 k<br>\u5146\u5b57\u8282(1024K) \u2013 M \u5409\u5b57\u8282(1024M) \u2013 G<\/p>\n\n\n\n<p>\u4f8b\uff1a <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>dd if=\/dev\/zero of=test.file bs=1M count=10<\/code><\/pre>\n\n\n\n<p> \u5728\u5f53\u524d\u6587\u4ef6\u5939\u4e0b\u521b\u5efa\u4e00\u4e2a\u5927\u5c0f\u4e3a10M\u7684\u6587\u4ef6test.file \u5185\u5bb9\u5168\u4e3a0<br>\/dev\/zero \u662f\u4e00\u4e2a\u5b57\u7b26\u8bbe\u5907\uff0c\u5b83\u4f1a\u4e0d\u65ad\u8fd4\u56de0\u503c\u5b57\u8282\uff08\/0\uff09.<br>\u5982\u679c\u4e0d\u6307\u5b9a\u8f93\u5165\u53c2\u6570(if)\uff0c\u9ed8\u8ba4\u60c5\u51b5\u4f1a\u4ecestdin\u8bfb\u53d6\u8f93\u5165\u3002\u5982\u679c\u4e0d\u6307\u5b9a\u8f93\u51fa\u53c2\u6570(of)\uff0c\u9ed8\u8ba4\u60c5\u51b5\u4f1a\u5c06stdout\u4f5c\u4e3a\u8f93\u51fa\u3002<br>\u4e5f\u53ef\u7528 dd \u547d\u4ee4\u6765\u4f20\u8f93\u5927\u91cf\u6570\u636e\u6765\u6d4b\u8bd5\u5185\u5b58\u7684\u64cd\u4f5c\u901f\u5ea6\u3002 <\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">$ dd if=\/dev\/zero of=.\/testmm.file bs=10M count=10\n\n\u8bb0\u5f55\u4e8610+0 \u7684\u8bfb\u5165\n\u8bb0\u5f55\u4e8610+0 \u7684\u5199\u51fa\n104857600\u5b57\u8282(105 MB)\u5df2\u590d\u5236\uff0c0.577581 \u79d2\uff0c182 MB\/\u79d2\n\n$ ll -h |grep \u2018testmm.file\u2019\n-rw-rw-r\u2013. 1 itudu itudu 100M 7\u6708 16 18:14 testmm.file<\/pre>\n\n\n\n<p>\n\u6587\u4ef6\u7c7b\u578b\uff1a<br>\u4e00\u822c\u6587\u4ef6\uff1a \u2013<br>\u76ee\u5f55\u6587\u4ef6\uff1a d<br>\u5b57\u7b26\u8bbe\u5907\uff1a c<br>\u5757\u8bbe\u5907: b<br>\u94fe\u63a5\u6587\u4ef6\uff1a l<br>\u5957\u63a5\u5b57\u6587\u4ef6: s<br>\u7ba1\u9053\u6587\u4ef6\uff1a p<\/p>\n\n\n\n<p>\u76ee\u5f55\u7684\u8bfb\u3001\u5199\u3001\u6267\u884c\u6743\u9650\u610f\u4e49\uff1a<br>\u8bfb\u6743\u9650\uff1a\u5141\u8bb8\u8bfb\u53d6\u76ee\u5f55\u4e2d\u6587\u4ef6\u548c\u5b50\u76ee\u5f55\u7684\u5217\u8868<br>\u5199\u6743\u9650\uff1a\u5141\u8bb8\u5728\u76ee\u5f55\u4e2d\u65b0\u5efa\u548c\u5220\u9664\u6587\u4ef6\u6216\u5b50\u76ee\u5f55<br>\u6267\u884c\u6743\u9650\uff1a\u53ef\u4ee5\u8bbf\u95ee\u76ee\u5f55\u4e2d\u7684\u6587\u4ef6\u548c\u5b50\u76ee\u5f55\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"<div class=\"slide-text-bg2\">\n<h3>d \u662f Linux\/UNIX \u4e0b\u7684\u4e00\u4e2a\u975e<\/h3>\n<\/div>\n<div class=\"flex-btn-div\"><a href=\"http:\/\/www.recologypower.com:9080\/?p=705\" class=\"btn1 flex-btn\">\u9605\u8bfb\u66f4\u591a<\/a><\/div>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[39],"tags":[],"_links":{"self":[{"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=\/wp\/v2\/posts\/705"}],"collection":[{"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=705"}],"version-history":[{"count":1,"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=\/wp\/v2\/posts\/705\/revisions"}],"predecessor-version":[{"id":706,"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=\/wp\/v2\/posts\/705\/revisions\/706"}],"wp:attachment":[{"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=705"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=705"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.recologypower.com:9080\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=705"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}