{"id":150,"date":"2010-10-23T15:50:09","date_gmt":"2010-10-23T07:50:09","guid":{"rendered":"http:\/\/www.ipcpu.com\/?p=150"},"modified":"2010-10-23T15:50:09","modified_gmt":"2010-10-23T07:50:09","slug":"dev-null-2-1","status":"publish","type":"post","link":"https:\/\/c.ipcpu.com\/2010\/10\/dev-null-2-1\/","title":{"rendered":">\/dev\/null 2>&1\u548c&>\/dev\/null.\u7684\u533a\u522b\u95ee\u9898"},"content":{"rendered":"

bash\u73af\u5883\u4f5c\u4e86\u5982\u4e0b\u5b9e\u9a8c\uff1a<\/p>\n

[root@s253.ipcpu.com ~]# balabala
\n-bash: balabala: command not found
\n[root@s253.ipcpu.com ~]# balabala &> \/dev\/null
\n[root@s253.ipcpu.com ~]# balabala >\/dev\/null 2>&1
\n[root@s253.ipcpu.com ~]# balabala > \/dev\/null 2>&1
\n[root@s253.ipcpu.com ~]#<\/p>\n

\u4e24\u6761\u547d\u4ee4\u7b49\u4ef7\u3002<\/p>\n

\u7f51\u53cb\u7ed9\u51faksh\u548cbash\u5bf9\u6bd4
\n\/home\/lee#echo $0
\n-ksh
\n\/home\/lee#ls abc >\/dev\/null 2>&1
\n\/home\/lee#ls abc &>\/dev\/null<\/span>
\nls: abc: \u6ca1\u6709\u90a3\u4e2a\u6587\u4ef6\u6216\u76ee\u5f55
\n[1] 1524
\n[1] + Done (1)???????????? ls \u2013color=tty abc
\n\/home\/lee#bash
\n\/home\/lee#echo $0
\nbash
\n\/home\/lee#ls abc >\/dev\/null 2>&1
\n\/home\/lee#ls abc &>\/dev\/null<\/span>
\n\u663e\u7136\u5728ksh\u5c31\u4e0d\u4e00\u6837\u4e86\uff0c\u6240\u4ee5\u63a8\u8350\u4f7f\u7528>\/dev\/null 2>&1<\/strong><\/p>\n

\u53c2\u8003\u8d44\u6599\uff1a
\nhttp:\/\/bbs.chinaunix.net\/viewthread.php?tid=610827<\/a><\/p>\n

\u540e\u8bb0\uff1a<\/p>\n

2>&1 \u548c &>? \u7684\u89e3\u91ca<\/p>\n

Linux\u7684IO\u8f93\u5165\u8f93\u51fa\u6709\u4e09\u7c7b<\/p>\n

Standard Input????? \u4ee3\u7801 0
\nStandard Output? \u4ee3\u7801? 1
\nStandard Error???? \u4ee3\u7801 2<\/p>\n

ls thereisno 1> out.txt? \u6807\u51c6\u8f93\u51fa\u91cd\u5b9a\u5411? \u4e5f\u53ef\u4ee5\u4e0d\u52a01\u5199\u6210 ls thereisno > out.txt<\/p>\n

?ls thereisno 2> out.txt? \u6807\u51c6\u9519\u8bef\u91cd\u5b9a\u5411<\/p>\n

?ls thereisno > out.txt? 2>&1? \u628a\u9519\u8bef\u5b9a\u5411\u5230\u6807\u51c6\u8f93\u51fa\uff0c\u7136\u540e\u7edf\u4e00\u91cd\u5b9a\u5411<\/p>\n

?ls thereisno &> out.txt? \u6240\u6709IO\u91cd\u5b9a\u5411(&>\u4e2d\u7684&\u53ef\u4ee5\u4ee3\u8868\u4efb\u610f\uff0c0\uff0c1\uff0c2\uff0c3\u2026\u2026)<\/p>\n

\u8f6c\u8f7d\u8bf7\u6ce8\u660e\uff1aIPCPU-\u7f51\u7edc\u4e4b\u8def<\/a> » >\/dev\/null 2>&1\u548c&>\/dev\/null.\u7684\u533a\u522b\u95ee\u9898<\/a><\/p>","protected":false},"excerpt":{"rendered":"

bash\u73af\u5883\u4f5c\u4e86\u5982\u4e0b\u5b9e\u9a8c\uff1a [root@s253.ipcpu.com ~]# balabala -bash: balabala: command not found [root@s253.ipcpu.com ~]# balabala &> \/dev\/null [root@s253.ipcpu.com ~]# balabala >\/dev\/null 2>&1 [root@s253.ipcpu.com ~]# balabala > \/dev\/null 2>&1 [root@s253.ipcpu.com ~]# \u4e24\u6761\u547d\u4ee4\u7b49\u4ef7\u3002 \u7f51\u53cb\u7ed9\u51faksh\u548cbash\u5bf9\u6bd4 \/home\/lee#echo $0 -ksh \/home\/lee#ls abc >\/dev\/null 2>&1 \/home\/lee#ls abc &>\/dev\/null ls: abc: \u6ca1\u6709\u90a3\u4e2a\u6587\u4ef6\u6216\u76ee\u5f55 [1] 1524 [1] + Done (1)???????????? ls \u2013color=tty abc \/home\/lee#bash \/home\/lee#echo $0 bash […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[13],"tags":[],"_links":{"self":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/150"}],"collection":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/comments?post=150"}],"version-history":[{"count":0,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/150\/revisions"}],"wp:attachment":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/media?parent=150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/categories?post=150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/tags?post=150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}