{"id":1622,"date":"2023-04-18T17:39:11","date_gmt":"2023-04-18T09:39:11","guid":{"rendered":"http:\/\/175.24.184.226\/?p=1622"},"modified":"2023-04-18T17:39:11","modified_gmt":"2023-04-18T09:39:11","slug":"linux%e4%b8%ad%e7%9a%84%e3%80%81%e3%80%81%e3%80%81%e3%80%81%e3%80%81","status":"publish","type":"post","link":"\/?p=1622","title":{"rendered":"Linux\u4e2d\u7684&\u3001&&\u3001|\u3001||\u3001$?\u3001$#"},"content":{"rendered":"

1.\u547d\u4ee4\uff1a|
\n\u8868\u793a\u7ba1\u9053\uff0c\u4e0a\u4e00\u6761\u547d\u4ee4\u7684\u8f93\u51fa\uff0c\u4f5c\u4e3a\u4e0b\u4e00\u6761\u547d\u4ee4\u53c2\u6570\uff0c\u5982\uff1als | grep \u201caa\u201d\uff0c\u5728ls\u7684\u8f93\u51fa\u4e2d\u67e5\u627eaa\u5b57\u7b26\u4e32\u3002<\/p>\n

2.\u547d\u4ee4\uff1a||
\n\u8868\u793a\u4e0a\u4e00\u6761\u547d\u4ee4\u6267\u884c\u5931\u8d25\u540e\uff0c\u624d\u6267\u884c\u4e0b\u4e00\u6761\u547d\u4ee4\uff0c\u5982 cat nofile || echo \u201cfail\u201d<\/p>\n

3.\u547d\u4ee4\uff1a&
\n\u8868\u793a\u4efb\u52a1\u5728\u540e\u53f0\u6267\u884c\uff0c\u6267\u884c\u7a0b\u5e8f\u7684\u540e\u9762\u6dfb\u52a0&\uff0c\u8fd9\u6837\u5728\u7a0b\u5e8f\u6267\u884c\u65f6\u6211\u4eec\u4ecd\u7136\u53ef\u4ee5\u64cd\u4f5c\u63a7\u5236\u53f0\u3002\u5982\u8981\u5728\u540e\u53f0\u8fd0\u884credis-server,\u5219\u6709 redis-server &<\/p>\n

4.\u547d\u4ee4\uff1a&&
\n\u8868\u793a\u524d\u4e00\u6761\u547d\u4ee4\u6267\u884c\u6210\u529f\u65f6\uff0c\u624d\u6267\u884c\u540e\u4e00\u6761\u547d\u4ee4 \uff0c\u5982 echo '1\u2018 && echo \u20182\u2019<\/p>\n

5.$?\u548c$#
\n$?\u662f\u6267\u884c\u4e0a\u4e00\u6761\u6307\u4ee4\u7684\u8fd4\u56de\u503c\uff1b$#\u662f\u8c03\u7528shell\u811a\u672c\u4f20\u9012\u7684\u53c2\u6570\u4e2a\u6570\uff0c\u6ce8\u610f\u8fd9\u91cc\u7684\u53c2\u6570\u4e2a\u6570\u548cC\u8bed\u8a00main\u51fd\u6570\u4f20\u53c2\u7684\u533a\u522b\uff1b\u53ef\u4ee5\u53c2\u8003\u535a\u5ba2shell\u7a0b\u5e8f\u4f20\u53c2\u548cmain\u51fd\u6570\u4f20\u53c2\u7684\u533a\u522b_\u6b63\u5728\u8d77\u98de\u7684\u8717\u725b\u7684\u535a\u5ba2-CSDN\u535a\u5ba2<\/a>\u3002
\n\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014
\n\u7248\u6743\u58f0\u660e\uff1a\u672c\u6587\u4e3aCSDN\u535a\u4e3b\u300c\u6b63\u5728\u8d77\u98de\u7684\u8717\u725b\u300d\u7684\u539f\u521b\u6587\u7ae0\uff0c\u9075\u5faaCC 4.0 BY-SA\u7248\u6743\u534f\u8bae\uff0c\u8f6c\u8f7d\u8bf7\u9644\u4e0a\u539f\u6587\u51fa\u5904\u94fe\u63a5\u53ca\u672c\u58f0\u660e\u3002
\n\u539f\u6587\u94fe\u63a5\uff1ahttps:\/\/blog.csdn.net\/weixin_42031299\/article\/details\/120107370<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

1.\u547d\u4ee4\uff1a| \u8868\u793a\u7ba1\u9053\uff0c\u4e0a\u4e00\u6761\u547d\u4ee4\u7684\u8f93\u51fa\uff0c\u4f5c\u4e3a\u4e0b\u4e00\u6761\u547d\u4ee4\u53c2\u6570\uff0c\u5982\uff1als | grep \u201caa\u201d\uff0c\u5728ls\u7684\u8f93\u51fa\u4e2d\u67e5\u627eaa\u5b57\u7b26\u4e32\u3002 2.\u547d\u4ee4 \u2026 …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[14],"tags":[15,138],"_links":{"self":[{"href":"\/index.php?rest_route=\/wp\/v2\/posts\/1622"}],"collection":[{"href":"\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1622"}],"version-history":[{"count":1,"href":"\/index.php?rest_route=\/wp\/v2\/posts\/1622\/revisions"}],"predecessor-version":[{"id":1623,"href":"\/index.php?rest_route=\/wp\/v2\/posts\/1622\/revisions\/1623"}],"wp:attachment":[{"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1622"},{"taxonomy":"post_tag","embeddable":true,"href":"\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}