{"id":1905,"date":"2012-08-04T13:00:00","date_gmt":"2012-08-04T05:00:00","guid":{"rendered":""},"modified":"2013-11-21T18:29:28","modified_gmt":"2013-11-21T10:29:28","slug":"shell-%e5%ad%97%e7%ac%a6%e4%b8%b2%e6%93%8d%e4%bd%9c%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/kyle.ai\/blog\/1905.html","title":{"rendered":"shell \u5b57\u7b26\u4e32\u64cd\u4f5c\u8be6\u89e3"},"content":{"rendered":"

\u4e00\u3001\u5224\u65ad\u8bfb\u53d6\u5b57\u7b26\u4e32\u503c<\/p>\n

\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u8868\u8fbe\u5f0f<\/th>\n\u542b\u4e49<\/th>\n<\/tr>\n<\/thead>\n
${var}<\/td>\n\u53d8\u91cfvar\u7684\u503c, \u4e0e$var\u76f8\u540c<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${var-DEFAULT}<\/td>\n\u5982\u679cvar\u6ca1\u6709\u88ab\u58f0\u660e, \u90a3\u4e48\u5c31\u4ee5$DEFAULT\u4f5c\u4e3a\u5176\u503c *<\/td>\n<\/tr>\n
${var:-DEFAULT}<\/td>\n\u5982\u679cvar\u6ca1\u6709\u88ab\u58f0\u660e, \u6216\u8005\u5176\u503c\u4e3a\u7a7a, \u90a3\u4e48\u5c31\u4ee5$DEFAULT\u4f5c\u4e3a\u5176\u503c *<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${var=DEFAULT}<\/td>\n\u5982\u679cvar\u6ca1\u6709\u88ab\u58f0\u660e, \u90a3\u4e48\u5c31\u4ee5$DEFAULT\u4f5c\u4e3a\u5176\u503c *<\/td>\n<\/tr>\n
${var:=DEFAULT}<\/td>\n\u5982\u679cvar\u6ca1\u6709\u88ab\u58f0\u660e, \u6216\u8005\u5176\u503c\u4e3a\u7a7a, \u90a3\u4e48\u5c31\u4ee5$DEFAULT\u4f5c\u4e3a\u5176\u503c *<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${var+OTHER}<\/td>\n\u5982\u679cvar\u58f0\u660e\u4e86, \u90a3\u4e48\u5176\u503c\u5c31\u662f$OTHER, \u5426\u5219\u5c31\u4e3anull\u5b57\u7b26\u4e32<\/td>\n<\/tr>\n
${var:+OTHER}<\/td>\n\u5982\u679cvar\u88ab\u8bbe\u7f6e\u4e86, \u90a3\u4e48\u5176\u503c\u5c31\u662f$OTHER, \u5426\u5219\u5c31\u4e3anull\u5b57\u7b26\u4e32<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${var?ERR_MSG}<\/td>\n\u5982\u679cvar\u6ca1\u88ab\u58f0\u660e, \u90a3\u4e48\u5c31\u6253\u5370$ERR_MSG *<\/td>\n<\/tr>\n
${var:?ERR_MSG}<\/td>\n\u5982\u679cvar\u6ca1\u88ab\u8bbe\u7f6e, \u90a3\u4e48\u5c31\u6253\u5370$ERR_MSG *<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${!varprefix*}<\/td>\n\u5339\u914d\u4e4b\u524d\u6240\u6709\u4ee5varprefix\u5f00\u5934\u8fdb\u884c\u58f0\u660e\u7684\u53d8\u91cf<\/td>\n<\/tr>\n
${!varprefix@}<\/td>\n\u5339\u914d\u4e4b\u524d\u6240\u6709\u4ee5varprefix\u5f00\u5934\u8fdb\u884c\u58f0\u660e\u7684\u53d8\u91cf<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4e8c\u3001\u5b57\u7b26\u4e32\u64cd\u4f5c\uff08\u957f\u5ea6\uff0c\u8bfb\u53d6\uff0c\u66ff\u6362\uff09<\/p>\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u8868\u8fbe\u5f0f<\/th>\n\u542b\u4e49<\/th>\n<\/tr>\n<\/thead>\n
${#string}<\/td>\n$string\u7684\u957f\u5ea6<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${string:position}<\/td>\n\u5728$string\u4e2d, \u4ece\u4f4d\u7f6e$position\u5f00\u59cb\u63d0\u53d6\u5b50\u4e32<\/td>\n<\/tr>\n
${string:position:length}<\/td>\n\u5728$string\u4e2d, \u4ece\u4f4d\u7f6e$position\u5f00\u59cb\u63d0\u53d6\u957f\u5ea6\u4e3a$length\u7684\u5b50\u4e32<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${string#substring}<\/td>\n\u4ece\u53d8\u91cf$string\u7684\u5f00\u5934, \u5220\u9664\u6700\u77ed\u5339\u914d$substring\u7684\u5b50\u4e32<\/td>\n<\/tr>\n
${string##substring}<\/td>\n\u4ece\u53d8\u91cf$string\u7684\u5f00\u5934, \u5220\u9664\u6700\u957f\u5339\u914d$substring\u7684\u5b50\u4e32<\/td>\n<\/tr>\n
${string%substring}<\/td>\n\u4ece\u53d8\u91cf$string\u7684\u7ed3\u5c3e, \u5220\u9664\u6700\u77ed\u5339\u914d$substring\u7684\u5b50\u4e32<\/td>\n<\/tr>\n
${string%%substring}<\/td>\n\u4ece\u53d8\u91cf$string\u7684\u7ed3\u5c3e, \u5220\u9664\u6700\u957f\u5339\u914d$substring\u7684\u5b50\u4e32<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n
${string\/substring\/replacement}<\/td>\n\u4f7f\u7528$replacement, \u6765\u4ee3\u66ff\u7b2c\u4e00\u4e2a\u5339\u914d\u7684$substring<\/td>\n<\/tr>\n
${string\/\/substring\/replacement}<\/td>\n\u4f7f\u7528$replacement, \u4ee3\u66ff\u6240\u6709\u5339\u914d\u7684$substring<\/td>\n<\/tr>\n
${string\/#substring\/replacement}<\/td>\n\u5982\u679c$string\u7684\u524d\u7f00\u5339\u914d$substring, \u90a3\u4e48\u5c31\u7528$replacement\u6765\u4ee3\u66ff\u5339\u914d\u5230\u7684$substring<\/td>\n<\/tr>\n
${string\/%substring\/replacement}<\/td>\n\u5982\u679c$string\u7684\u540e\u7f00\u5339\u914d$substring, \u90a3\u4e48\u5c31\u7528$replacement\u6765\u4ee3\u66ff\u5339\u914d\u5230\u7684$substring<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

\u4e00\u3001\u5224\u65ad\u8bfb\u53d6\u5b57\u7b26\u4e32\u503c \u8868\u8fbe\u5f0f \u542b\u4e49 ${var} \u53d8\u91cfvar\u7684\u503c, \u4e0e$var\u76f8\u540c ${var-DEFAULT […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-1905","post","type-post","status-publish","format-standard","hentry","category-skill"],"_links":{"self":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/1905","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/comments?post=1905"}],"version-history":[{"count":1,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/1905\/revisions"}],"predecessor-version":[{"id":5022,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/posts\/1905\/revisions\/5022"}],"wp:attachment":[{"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/media?parent=1905"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/categories?post=1905"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kyle.ai\/blog\/wp-json\/wp\/v2\/tags?post=1905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}