{"id":430,"date":"2021-07-28T18:24:24","date_gmt":"2021-07-28T10:24:24","guid":{"rendered":"https:\/\/egonlin.com\/?p=430"},"modified":"2021-07-30T10:27:12","modified_gmt":"2021-07-30T02:27:12","slug":"shell%e8%a7%a3%e9%87%8a%e5%99%a8%e4%ba%a4%e4%ba%92%e5%bc%8f%e7%8e%af%e5%a2%83","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=430","title":{"rendered":"shell\u89e3\u91ca\u5668\u4ea4\u4e92\u5f0f\u73af\u5883"},"content":{"rendered":"

shell\u89e3\u91ca\u5668\u4ea4\u4e92\u5f0f\u73af\u5883<\/h1>\n

\u4e00 \u4ea4\u4e92\u5f0f\u73af\u5883\u4ecb\u7ecd<\/h2>\n

\u542f\u52a8\u64cd\u4f5c\u7cfb\u7edf\u540e\uff0clinux\u7cfb\u7edf\u4f1a\u9ed8\u8ba4\u63d0\u4f9b5\u4e2a\u64cd\u4f5c\u7ec8\u7aef\uff08multics=\u300bunix=\u300b\u3002\u3002\u3002=\u300blinux\uff09\uff0c\u53ef\u4ee5\u7528Ctrl + Alt + Fn(n=1,2,3,4,5...)<\/code>\u5feb\u6377\u952e\u5207\u6362\uff0c\u6211\u4eec\u8fdb\u5165\u4efb\u610f\u7ec8\u7aef\u540e\u8f93\u5165\u8d26\u53f7\u5bc6\u7801\u767b\u5f55\u7528\u6237\u540e\uff0c\u5c31\u4f1a\u6267\u884c\u8be5\u7528\u6237\u5728\/etc\/passwd\u6587\u4ef6\u4e2d\u6307\u5b9a\u7684\u89e3\u91ca\u5668\u7a0b\u5e8f\uff0c\u7136\u540e\u8fdb\u5165\u89e3\u91ca\u5668\u7684\u4ea4\u4e92\u5f0f\u73af\u5883<\/p>\n

[root@localhost ~]# head -1 \/etc\/passwd\nroot:x:0:0:root:\/root:\/bin\/bash  # \u6700\u540e\u4e00\u4e2a\u5b57\u6bb5\u5c31\u662f\u6307\u5b9a\u7684\u89e3\u91ca\u5668\u7a0b\u5e8f<\/code><\/pre>\n
\u4f55\u4e3a\u4ea4\u4e92\u5f0f\u73af\u5883\uff1f\uff1f\uff1f<\/p>\n
1\u3001\u6211\u4eec\u4e3a\u89e3\u91ca\u5668\u8f93\u5165\u6307\u4ee4\uff0c\u89e3\u91ca\u5668\u89e3\u91ca\u6267\u884c\uff08\u8c03\u7528\u64cd\u4f5c\u7cfb\u7edf\u63a5\u53e3\u6267\u884c\uff09\u7136\u540e\u540e\u7ed9\u6211\u4eec\u8fd4\u56de\u7ed3\u679c\uff0c\u8fd9\u5c31\u53eb\u4ea4\u4e92\n\n2\u3001\u8fdb\u5165\u89e3\u91ca\u5668\u4ea4\u4e92\u5f0f\u73af\u5883\u540e\u666e\u901a\u7528\u6237\u7684\u63d0\u793a\u7b26\u662f$,\u7ba1\u7406\u7528\u6237\u662f#\n\n3\u3001shell\u547d\u4ee4\u7684\u57fa\u672c\u683c\u5f0f\/\u8bed\u6cd5\u683c\u5f0f\uff1a\u547d\u4ee4 \u9009\u9879 \u53c2\u6570<\/code><\/pre>\n
\u4e8c \u547d\u4ee4\u4f18\u5148\u7ea7\u4ece\u9ad8\u5230\u4f4e<\/h2>\n
==> alias\n\u3000\u3000==> Compound Commands\n\u3000\u3000\u3000\u3000==> function\n\u3000\u3000\u3000\u3000\u3000\u3000==> build_in\n\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000==> hash\n\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000==> $PATH\n\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000==> error: command not found\n\n#1\u3001alias\u522b\u540d\n\u53ef\u4ee5\u7528alias\u67e5\u770b\n\u53ef\u4ee5\u7528\u547d\u4ee4\u6765\u5236\u4f5c\uff1aalias \u522b\u540d="\u547d\u4ee4 \u9009\u9879 \u53c2\u6570"\n\n#2\u3001Compound Commands\u590d\u5408\u547d\u4ee4\n\u590d\u5408\u547d\u4ee4\u6307\u7684\u662f\u80fd\u591f\u5c06\u4e00\u7ec4\u547d\u4ee4\u5c01\u88c5\u5230\u4e00\u4e2a\u4ee3\u7801\u5757\u91cc\u7684\u547d\u4ee4\uff0c\u4f8b\u5982if\u3001for\u3001while\u7b49\n\n#3\u3001function\u51fd\u6570\n\n#4\u3001build in\u5185\u5efa\u547d\u4ee4\n\u53ef\u4ee5\u7528type\u67e5\u770b\uff0c\u6216\u8005\u7528man builtin\n[root@egon ~]# type cd\ncd \u662f shell \u5185\u5d4c\n\n#5\u3001hash\n\u5f53\u522b\u540d\u548c\u5185\u90e8\u547d\u4ee4\u90fd\u641c\u5230\u4e0d\u5230\u547d\u4ee4\u65f6\uff0c\u4f1a\u68c0\u7d22$PATH\u4e2d\u7684\u8def\u5f84\n[root@egon ~]# sed -n 's\/:\/\\n\/gp' <<< $PATH\n\/usr\/local\/sbin\n\/usr\/local\/bin\n\/usr\/sbin\n\/usr\/bin\n\/root\/bin\n\n\u4f46\u662f$PATH\u4e2d\u5305\u542b\u7684\u8def\u5f84\u592a\u591a\u4e86\uff0c\u800c\u4e14\u6bcf\u4e2a\u8def\u5f84\u4e2d\u7684\u53ef\u6267\u884c\u6587\u4ef6\u4e5f\u5f88\u591a\n\u5982\u679c\u6bcf\u6b21\u90fd\u8981\u641c\u7d22\u6bcf\u4e2a\u8def\u5f84\u4e0b\u7684\u6240\u6709\u53ef\u6267\u884c\u6587\u4ef6,\u663e\u7136\u662f\u4e0d\u660e\u667a\u7684\n\u4e3a\u4e86\u51cf\u5c11$PATH\u7684\u641c\u7d22,\u4e0a\u4e00\u6b21\u641c\u7d22\u7684\u5185\u5bb9\u80fd\u591f\u88ab\u4e0b\u4e00\u6b21\u6267\u884c\u91cd\u7528\nbash\u5bf9\u4ece$PATH\u4e2d\u641c\u7d22\u5f97\u51fa\u7684\u5916\u90e8\u547d\u4ee4\u5efa\u7acb\u4e00\u4e2ahash\u8868,\u7528\u4e8e\u7f13\u5b58\n\u8fd9\u4e2a\u7f13\u5b58\u662f\u4f1a\u8bdd\u7ea7\u522b\u72ec\u7acb\u62e5\u6709\u7684.\u4e0d\u53ef\u4ee5\u5bf9\u5176\u4ed6\u7ec8\u7aef\u5171\u4eab,\u56e0\u4e3a\u6bcf\u4e2a\u7528\u6237\u7684$PATH\u53ef\u80fd\u4e0d\u540c\n[root@egon ~]# hostname  # \u6267\u884c\u4e00\u6b21$PATH\u4e2d\u7684\u547d\u4ee4\uff0clinux\u7cfb\u7edf\u5c31\u4f1a\u5c06\u5176\u7f13\u5b58\u8d77\u6765\negon.xxx.com\n[root@egon ~]# hash      # \u53ef\u4ee5\u67e5\u770bhash\u8868\u7684\u7f13\u5b58\n\u547d\u4e2d  \u547d\u4ee4\n   2    \/usr\/bin\/hostname\n   1    \/usr\/bin\/sed\n   2    \/usr\/bin\/man\n   1    \/usr\/bin\/ls\n[root@egon ~]# hash -r   # \u4e5f\u53ef\u4ee5\u6e05\u7a7a\u6389\n[root@egon ~]# hash\nhash: \u54c8\u5e0c\u8868\u4e3a\u7a7a\n\n#6\u3001$PATH\n\u7565\n\n==========================\u4f18\u5148\u7ea7\u9a8c\u8bc1======================\n===========alias > Compound Commands > function=========\n#(1) \u8bbe\u7f6e\n[root@egon ~]# alias if="ls -l"\n[root@egon ~]# function if(){\n> echo "123"\n> }\n\n#(2) \u9a8c\u8bc1alias\u7684\u4f18\u5148\u7ea7\u6700\u9ad8\n[root@egon ~]# if  \n\u603b\u7528\u91cf 12\n-rw-r--r-x. 1 root root 44 8\u6708  13 19:36 1.sh\n-rw-r--r-x. 1 root root 44 8\u6708  13 19:36 2.sh\n-rw-r--r-x. 1 root root 44 8\u6708  13 19:37 3.sh\n\n#(3) \u53d6\u6d88\u522b\u540d\uff0c\u9a8c\u8bc1\u590d\u5408\u547d\u4ee4\u4f18\u5148\u7ea7>function\n[root@egon ~]# unalias if \n[root@egon ~]# if  # \u6267\u884c\u7684\u662f\u590d\u5408\u547d\u4ee4\u800c\u4e0d\u662f\u51fd\u6570\n> \n\n===========function > buitin=========\n#(1) \u8bbe\u7f6e\n[root@egon ~]# function cd(){\n> echo "\u81ea\u5b9a\u4e49\u51fd\u6570cd"\n> }\n[root@egon ~]# \n[root@egon ~]# type cd\ncd \u662f\u51fd\u6570\ncd () \n{ \n    echo "\u81ea\u5b9a\u4e49\u51fd\u6570cd"\n}\n#(2) \u9a8c\u8bc1\n[root@egon ~]# cd  # \u6267\u884c\u7684\u662f\u51fd\u6570\n\u81ea\u5b9a\u4e49\u51fd\u6570cd\n\n===========buitin > hash > $PATH=========\n#\uff081\uff09\u6700\u5f00\u59cbhash\u8868\u5185\u662f\u6ca1\u6709\u4efb\u4f55\u547d\u4ee4\u7684,\u4f18\u5148\u7ea7:builtin > $PATH\n[root@egon ~]# unset cd\n[root@egon ~]# type cd\ncd \u662f shell \u5185\u5d4c\n[root@egon ~]# cat \/usr\/bin\/cd\n#!\/bin\/sh\necho "\u8fd9\u662fPATH\u5185\u7684\u4e00\u4e2acd\u811a\u672c"\n[root@egon ~]# chmod +x \/usr\/bin\/cd\n[root@egon ~]# cd # \u6267\u884c\u7684\u662f\u5185\u7f6e\u547d\u4ee4\uff0c\u800c\u4e0d\u662f$PATH\u4e0b\u7684\u811a\u672ccd\n\n[root@egon ~]# cp \/usr\/bin\/cd \/usr\/bin\/hahaha\n[root@egon ~]# hahaha \n\u8fd9\u662fPATH\u5185\u7684\u4e00\u4e2acd\u811a\u672c\n[root@egon ~]# \n\n#\uff082\uff09\u540e\u6765hash\u8868\u4e2d\u6709\u547d\u4ee4\uff0c\u4f46\u5b83\u7f13\u5b58\u7684\u662f$PATH\u4e2d\u7684\u547d\u4ee4\uff0c\u8bf4\u767d\u4e86\uff0c\u4e0e$PATH\u90fd\u662f\u4e00\u6837\u7684\u4e1c\u897f\uff0c\u5185\u7f6e\u547d\u4ee4\u7684\u4f18\u5148\u7ea7\u80af\u5b9a\u9ad8\u4e8ehash\n\n# (3) \u4f18\u5148\u7ea7hash>$PATH\n[root@egon ~]# hash -r\n[root@egon ~]# hostname\negon.xxx.com\n[root@egon ~]# hash \n\u547d\u4e2d  \u547d\u4ee4\n   1    \/usr\/bin\/hostname\n[root@egon ~]# hostname\negon.xxx.com\n[root@egon ~]# hash  # \u7f13\u5b58\u547d\u4e2d2\u6b21\n\u547d\u4e2d  \u547d\u4ee4\n   2    \/usr\/bin\/hostname<\/code><\/pre>\n
\u4e09 bash\u7684\u7279\u6027<\/h2>\n
<\/p>
<\/div>
\u67e5\u770b\u66f4\u591a<\/h2>
\u8054\u7cfb\u7ba1\u7406\u5458\u5fae\u4fe1tutu19192010\uff0c\u6ce8\u518c\u8d26\u53f7<\/p>\n<\/div>
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Register<\/a><\/div>
Forgotten username or password?<\/a><\/div>
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<\/div>","protected":false},"excerpt":{"rendered":"
shell\u89e3\u91ca\u5668\u4ea4\u4e92\u5f0f\u73af\u5883 \u4e00 \u4ea4\u4e92\u5f0f\u73af\u5883\u4ecb\u7ecd \u542f\u52a8\u64cd\u4f5c\u7cfb\u7edf\u540e\uff0clinux\u7cfb\u7edf\u4f1a\u9ed8\u8ba4\u63d0\u4f9b5\u4e2a\u64cd\u4f5c\u7ec8\u7aef\uff08mult […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[74],"tags":[21,19,75,22,20],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/430"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=430"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/430\/revisions"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=430"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=430"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=430"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}