{"id":63869,"date":"2025-04-29T11:35:52","date_gmt":"2025-04-29T03:35:52","guid":{"rendered":"https:\/\/fwq.ai\/blog\/63869\/"},"modified":"2025-04-29T11:35:52","modified_gmt":"2025-04-29T03:35:52","slug":"linux-shell%e5%91%bd%e4%bb%a4if%e6%80%8e%e4%b9%88%e5%86%99-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/63869\/","title":{"rendered":"linux\u00a0shell\u547d\u4ee4if\u600e\u4e48\u5199"},"content":{"rendered":"<blockquote><p>\n  linux shell \u4e2d\u7684 if \u547d\u4ee4\u901a\u8fc7\u68c0\u67e5\u6761\u4ef6\u6765\u6267\u884c\u7279\u5b9a\u547d\u4ee4\u3002\u6761\u4ef6\u53ef\u4ee5\u662f\u6587\u4ef6\u5b58\u5728\u3001\u5b57\u7b26\u4e32\u6bd4\u8f83\u6216\u5e03\u5c14\u8868\u8fbe\u5f0f\u3002\u5982\u679c\u6761\u4ef6\u4e3a\u771f\uff0c\u5219\u6267\u884c then \u540e\u9762\u7684\u547d\u4ee4\uff1b\u5426\u5219\uff0c\u6267\u884c fi \u540e\u9762\u7684\u547d\u4ee4\u3002\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202406\/27\/2024062701492619471.jpg\" class=\"aligncenter\" title=\"linux\u00a0shell\u547d\u4ee4if\u600e\u4e48\u5199\u63d2\u56fe\" alt=\"linux\u00a0shell\u547d\u4ee4if\u600e\u4e48\u5199\u63d2\u56fe\" \/><\/p>\n<p><strong>Linux Shell \u547d\u4ee4 if \u7684\u7528\u6cd5<\/strong><\/p>\n<p><strong>if \u8bed\u53e5\u7684\u8bed\u6cd5<\/strong><\/p>\n<p>`if [ \u6761\u4ef6 ]; then<br \/> \u547d\u4ee4 <br \/>fi`<\/p>\n<p>\u5176\u4e2d\uff1a<\/p>\n<ul>\n<li>[ \u6761\u4ef6 ]\uff1a\u8981\u68c0\u67e5\u7684\u6761\u4ef6\u3002<\/li>\n<li>then\uff1a\u5982\u679c\u6761\u4ef6\u4e3a\u771f\uff0c\u5219\u6267\u884c\u7684\u547d\u4ee4\u3002<\/li>\n<li>fi\uff1a\u7ed3\u675f if \u8bed\u53e5\u3002<\/li>\n<\/ul>\n<p><strong>\u6761\u4ef6<\/strong><\/p>\n<p>\u6761\u4ef6\u53ef\u4ee5\u662f\u6bd4\u8f83\u8fd0\u7b97\u7b26\u3001\u5b57\u7b26\u4e32\u6bd4\u8f83\u6216\u5e03\u5c14\u8868\u8fbe\u5f0f\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u89c1\u7684\u6761\u4ef6\uff1a<\/p>\n<ul>\n<li>[ -f \u6587\u4ef6 ]\uff1a\u5982\u679c\u6587\u4ef6\u5b58\u5728\uff0c\u5219\u4e3a\u771f\u3002<\/li>\n<li>[ &#8220;$\u53d8\u91cf&#8221; != &#8220;&#8221; ]\uff1a\u5982\u679c\u53d8\u91cf\u4e0d\u4e3a\u7a7a\uff0c\u5219\u4e3a\u771f\u3002<\/li>\n<li>[ &#8220;$\u53d8\u91cf1&#8221; = &#8220;$\u53d8\u91cf2&#8221; ]\uff1a\u5982\u679c\u53d8\u91cf 1 \u7b49\u4e8e\u53d8\u91cf 2\uff0c\u5219\u4e3a\u771f\u3002<\/li>\n<li>[ &#8220;$\u6761\u4ef61&#8221; -eq &#8220;$\u6761\u4ef62&#8221; ]\uff1a\u5982\u679c\u6761\u4ef6 1 \u7b49\u4e8e\u6761\u4ef6 2\uff0c\u5219\u4e3a\u771f\u3002<\/li>\n<\/ul>\n<p><strong>\u547d\u4ee4<\/strong><\/p>\n<p>if \u8bed\u53e5\u4e2d\u53ef\u4ee5\u6267\u884c\u4efb\u4f55 Shell \u547d\u4ee4\u3002\u901a\u5e38\uff0c\u8fd9\u4e9b\u547d\u4ee4\u7528\u4e8e\u6839\u636e\u6761\u4ef6\u6267\u884c\u7279\u5b9a\u64cd\u4f5c\uff0c\u4f8b\u5982\u8f93\u51fa\u6d88\u606f\u3001\u9000\u51fa\u811a\u672c\u6216\u8c03\u7528\u5176\u4ed6\u547d\u4ee4\u3002<\/p>\n<p><strong>\u5b9e\u4f8b<\/strong><\/p>\n<p>\u4ee5\u4e0b\u5b9e\u4f8b\u4f7f\u7528 if \u8bed\u53e5\u68c0\u67e5\u6587\u4ef6\u662f\u5426\u5b58\u5728\uff1a<\/p>\n<pre>if [ -f \/tmp\/file.txt ]; then\n  echo \"\u6587\u4ef6\u5b58\u5728\"\nfi<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4ee5\u4e0b\u5b9e\u4f8b\u4f7f\u7528 if \u8bed\u53e5\u6839\u636e\u7528\u6237\u8f93\u5165\u6267\u884c\u4e0d\u540c\u64cd\u4f5c\uff1a<\/p>\n<pre>echo \"\u8f93\u5165\u6587\u4ef6\u540d\uff1a\"\nread filename\n\nif [ -f \"$filename\" ]; then\n  echo \"$filename \u6587\u4ef6\u5b58\u5728\"\nelse\n  echo \"$filename \u6587\u4ef6\u4e0d\u5b58\u5728\"\nfi<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f&nbsp;shell\u547d\u4ee4if\u600e\u4e48\u5199\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8FDCServers\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>linux shell \u4e2d\u7684 if \u547d\u4ee4\u901a\u8fc7\u68c0\u67e5\u6761\u4ef6\u6765\u6267\u884c\u7279\u5b9a\u547d\u4ee4\u3002\u6761\u4ef6\u53ef\u4ee5\u662f\u6587\u4ef6\u5b58\u5728\u3001\u5b57\u7b26\u4e32\u6bd4\u8f83\u6216\u5e03\u5c14\u8868\u8fbe\u5f0f\u3002\u5982\u679c\u6761\u4ef6\u4e3a\u771f\uff0c\u5219\u6267\u884c then \u540e\u9762\u7684\u547d\u4ee4\uff1b\u5426\u5219\uff0c\u6267\u884c fi \u540e\u9762\u7684\u547d\u4ee4\u3002 Linux Shell \u547d\u4ee4 if \u7684\u7528\u6cd5 if \u8bed\u53e5\u7684\u8bed\u6cd5 `if [ \u6761\u4ef6 ]; then \u547d\u4ee4 fi` \u5176\u4e2d\uff1a [ \u6761\u4ef6 ]\uff1a\u8981\u68c0\u67e5\u7684\u6761\u4ef6\u3002 then\uff1a\u5982\u679c\u6761\u4ef6\u4e3a\u771f\uff0c\u5219\u6267\u884c\u7684\u547d\u4ee4\u3002 fi\uff1a\u7ed3\u675f if \u8bed\u53e5\u3002 \u6761\u4ef6 \u6761\u4ef6\u53ef\u4ee5\u662f\u6bd4\u8f83\u8fd0\u7b97\u7b26\u3001\u5b57\u7b26\u4e32\u6bd4\u8f83\u6216\u5e03\u5c14\u8868\u8fbe\u5f0f\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u89c1\u7684\u6761\u4ef6\uff1a [ -f \u6587\u4ef6 ]\uff1a\u5982\u679c\u6587\u4ef6\u5b58\u5728\uff0c\u5219\u4e3a\u771f\u3002 [ &#8220;$\u53d8\u91cf&#8221; != &#8220;&#8221; ]\uff1a\u5982\u679c\u53d8\u91cf\u4e0d\u4e3a\u7a7a\uff0c\u5219\u4e3a\u771f\u3002 [ &#8220;$\u53d8\u91cf1&#8221; = &#8220;$\u53d8\u91cf2&#8221; ]\uff1a\u5982\u679c\u53d8\u91cf 1 \u7b49\u4e8e\u53d8\u91cf 2\uff0c\u5219\u4e3a\u771f\u3002 [ &#8220;$\u6761\u4ef61&#8221; -eq &#8220;$\u6761\u4ef62&#8221; ]\uff1a\u5982\u679c\u6761\u4ef6 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[],"class_list":["post-63869","post","type-post","status-publish","format-standard","hentry","category-os"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/63869","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=63869"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/63869\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=63869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=63869"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=63869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}