{"id":3484,"date":"2023-01-08T15:40:22","date_gmt":"2023-01-08T07:40:22","guid":{"rendered":"https:\/\/qaqaq.top\/?p=3484"},"modified":"2023-01-08T15:40:23","modified_gmt":"2023-01-08T07:40:23","slug":"linux%e7%b3%bb%e7%bb%9f%e7%8e%af%e5%a2%83%e4%b8%8bshell%e8%84%9a%e6%9c%ac%e5%bc%80%e5%8f%91%e9%80%89%e5%ad%a6","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=3484","title":{"rendered":"Linux\u7cfb\u7edf\u73af\u5883\u4e0bShell\u811a\u672c\u5f00\u53d1[\u9009\u5b66]"},"content":{"rendered":"\n

\u7b2c\u4e00\u8282 Shell\u7f16\u7a0b\u6982\u8ff0<\/h2>\n\n\n\n

Shell\u662f\u4e00\u4e2a\u547d\u4ee4\u884c\u89e3\u91ca\u5668\uff0c\u5b83\u63a5\u6536\u5e94\u7528\u7a0b\u5e8f\u6216\u7528\u6237\u7684\u547d\u4ee4\uff0c\u7136\u540e\u8c03\u7528\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u3002<\/p>\n\n\n\n

\"\"<\/div><\/figure>\n\n\n\n

Shell \u8fd9\u4e2a\u8bcd\u8fd8\u4ee3\u8868\u4e00\u4e2a\u529f\u80fd\u5f3a\u5927\u7684\u7f16\u7a0b\u8bed\u8a00\uff0c\u6613\u7f16\u5199\u3001\u6613\u8c03\u8bd5\u3001\u7075\u6d3b\u6027\u5f3a\u3002<\/p>\n\n\n\n

\u4e00\u3001Linux\u7cfb\u7edf\u63d0\u4f9b\u7684Shell\u89e3\u6790\u5668<\/h3>\n\n\n\n

\u6211\u4eec\u7f16\u5199\u7684Shell\u811a\u672c\u7a0b\u5e8f\uff0c\u9700\u8981\u7ecf\u8fc7Shell\u89e3\u6790\u5668\u7684\u89e3\u6790\uff0c\u624d\u80fd\u4ea4\u7ed9Linux\u7cfb\u7edf\u6267\u884c\u3002<\/p>\n\n\n\n

[root@hadoop101 ~]$ cat \/etc\/shells \n\/bin\/sh\n\/bin\/bash\n\/sbin\/nologin\n\/usr\/bin\/sh\n\/usr\/bin\/bash\n\/usr\/sbin\/nologin\n\/bin\/tcsh\n\/bin\/csh\n<\/code><\/pre>\n\n\n\n
\u5176\u4e2d\u6700\u5e38\u7528\u7684\u662f \/bin\/sh \u548c \/bin\/bash<\/p>\n\n\n\n
\u4e8c\u3001bash \u548c sh \u7684\u5173\u7cfb<\/h3>\n\n\n\n
[root@rich workspace]# ll \/bin\nlrwxrwxrwx. 1 root root 7 7\u6708   1 09:03 \/bin -> usr\/bin\n\n[root@apple w]# ll \/usr\/bin | grep bash$\n-rwxr-xr-x. 1 root root     964544 4\u6708  11 2018 bash\nlrwxrwxrwx. 1 root root          4 7\u6708   9 16:42 sh -> bash\n<\/code><\/pre>\n\n\n\n
sh\u662fbash\u7684\u8f6f\u94fe\u63a5<\/p>\n\n\n\n
\u4e09\u3001Linux\u9ed8\u8ba4\u7684\u89e3\u6790\u5668\u662fbash<\/h3>\n\n\n\n
[root@apple w]# echo $SHELL\n\/bin\/bash\n<\/code><\/pre>\n\n\n\n
\u56db\u3001Shell\u8bed\u6cd5\u603b\u8ff0<\/h3>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7b2c\u4e8c\u8282 Shell\u7f16\u7a0bHelloWorld<\/h2>\n\n\n\n
\u4e00\u3001\u521b\u5efa\u811a\u672c\u6587\u4ef6<\/h3>\n\n\n\n
\u901a\u5e38\u4ee5.sh\u4f5c\u4e3a\u6269\u5c55\u540d\uff0c\u8fd9\u4e0d\u662f\u4e00\u4e2a\u8bed\u6cd5\u5c42\u9762\u7684\u8981\u6c42\uff0c\u800c\u4ec5\u4ec5\u662f\u5927\u4f17\u7684\u4e60\u60ef\u3002<\/p>\n\n\n\n
\u4e8c\u3001\u811a\u672c\u5185\u5bb9<\/h3>\n\n\n\n
\u7b2c\u4e00\u884c\u6307\u5b9a\u5f53\u524d\u811a\u672c\u7684\u89e3\u6790\u5668\uff1a<\/p>\n\n\n\n
#!\/bin\/bash\n<\/code><\/pre>\n\n\n\n
\u5b9e\u73b0\u5177\u4f53\u529f\u80fd\uff1a<\/p>\n\n\n\n
echo \"hello world\"\n<\/code><\/pre>\n\n\n\n
\u5728Shell\u811a\u672c\u4e2d\uff0c#\u5f00\u5934\u7684\u90fd\u662f\u6ce8\u91ca\u3002#!\/bin\/bash\u76f8\u5f53\u4e8e\u5c31\u662f\u6ce8\u91ca\u5f62\u5f0f\u51fa\u73b0\u7684\u4e00\u4e2a\u56fa\u5b9a\u683c\u5f0f\uff0c\u544a\u8bc9Linux\u7cfb\u7edf\uff0c\u5f53\u524d\u4f7f\u7528\/bin\/bash\u89e3\u6790\u5668\u3002<\/p>\n\n\n\n
\u4e09\u3001Shell\u811a\u672c\u7684\u8fd0\u884c\u65b9\u5f0f<\/h3>\n\n\n\n
\u547d\u4ee4\u540d<\/th>\u5728\u5f53\u524d\u8fdb\u7a0b\u8fd0\u884c\u811a\u672c<\/th>\u65b0\u5efa\u5b50\u8fdb\u7a0b\u8fd0\u884c\u811a\u672c<\/th><\/tr><\/thead>
source<\/td>\u221a<\/td><\/td><\/tr>
.<\/td>\u221a<\/td><\/td><\/tr>
sh<\/td><\/td>\u221a<\/td><\/tr>
bash<\/td><\/td>\u221a<\/td><\/tr>
chmod +x\u540e\u76f4\u63a5\u8fd0\u884c<\/td><\/td>\u221a<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u5176\u4e2d\u201c.\u201d\u662fsource\u7684\u53e6\u4e00\u79cd\u5199\u6cd5\u3002\u5728\u5f53\u524d\u8fdb\u7a0b\u4e2d\u53d1\u5e03\u7684\u5168\u5c40\u53d8\u91cf\u53ef\u4ee5\u5728\u5f53\u524d\u8fdb\u7a0b\u7684\u5176\u4ed6\u811a\u672c\u4e2d\u7ee7\u7eed\u6cbf\u7528\uff0c\u4e5f\u53ef\u4ee5\u5728\u5b50\u8fdb\u7a0b\u4e2d\u4f7f\u7528\uff1b\u4f46\u662f\u5b50\u8fdb\u7a0bexport\u53d1\u5e03\u7684\u53d8\u91cf\u4ec5\u9650\u4e8e\u5b50\u8fdb\u7a0b\u5185\u90e8\u4f7f\u7528\u3002<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4ece\u4e0a\u9762\u8fdb\u7a0b\u6811\u4e2d\u80fd\u591f\u770b\u5230\uff0csh\u3001bash\u3001\u76f4\u63a5\u8fd0\u884c\u8fd9\u4e09\u79cd\u65b9\u5f0f\u786e\u5b9e\u662f\u5f00\u8f9f\u65b0\u7684\u5b50\u8fdb\u7a0b\u8fd0\u884c\u811a\u672c\u4e2d\u7684\u4ee3\u7801\u3002<\/p>\n\n\n\n
\u987a\u4fbf\u4e00\u63d0\uff1a\u5f53\u6211\u4eec\u7ed9\u4e00\u4e2a\u811a\u672c\u6587\u4ef6\u901a\u8fc7chmod\u547d\u4ee4+x\u64cd\u4f5c\u9644\u52a0\u4e86\u6267\u884c\u6743\u9650\uff0c\u6b64\u65f6\u9700\u8981\u901a\u8fc7\u8def\u5f84\u8bbf\u95ee\u5230\u8fd9\u4e2a\u6587\u4ef6\uff0c\u5426\u5219\u5c31\u5fc5\u987b\u52a0\u5165PATH\u73af\u5883\u53d8\u91cf\u3002\u4e0d\u4ee5\u8def\u5f84\u7684\u5f62\u5f0f\u8c03\u7528\uff0c\u5c31\u4f1a\u770b\u5230\u4e0b\u9762\u9519\u8bef\u63d0\u793a\uff1a<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u6b64\u65f6\u8981\u4e48\u628a\u811a\u672c\u6587\u4ef6\u6240\u5728\u76ee\u5f55\u6dfb\u52a0\u5230PATH\u73af\u5883\u53d8\u91cf\u4e2d\uff0c\u8981\u4e48\u901a\u8fc7\u8def\u5f84\u8bbf\u95ee\u548c\u8c03\u7528\uff1a<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u7b2c\u4e09\u8282 \u53d8\u91cf<\/h2>\n\n\n\n
\u4e00\u3001\u7cfb\u7edf\u9884\u5b9a\u4e49\u53d8\u91cf<\/h3>\n\n\n\n
\u5e38\u7528\u7cfb\u7edf\u53d8\u91cf\u5305\u62ec\uff1aUSER\u3001HOME\u3001PWD\u3001SHELL\u7b49\uff0c\u53ef\u4ee5\u4f7f\u7528echo\u547d\u4ee4\u8f93\u51fa\u5b83\u4eec\u7684\u503c\u3002<\/p>\n\n\n\n
\u4e8c\u3001\u4f7f\u7528set\u547d\u4ee4\u67e5\u770b<\/h3>\n\n\n\n
ABRT_DEBUG_LOG=\/dev\/null\nBASH=\/bin\/bash\nBASHOPTS=checkwinsize:cmdhist:expand_aliases:extglob:extquote:force_fignore:histappend:interactive_comments:login_shell:progcomp:promptvars:sourcepath\nBASH_ALIASES=()\nBASH_ARGC=()\nBASH_ARGV=()\n\u2026\u2026\n<\/code><\/pre>\n\n\n\n
\u4e09\u3001\u81ea\u5b9a\u4e49\u53d8\u91cf<\/h3>\n\n\n\n
1\u3001\u57fa\u672c\u8bed\u6cd5<\/h4>\n\n\n\n
\u2460\u5b9a\u4e49\u53d8\u91cf<\/h5>\n\n\n\n
USER_NAME=tom\n<\/code><\/pre>\n\n\n\n
\u2461\u5f15\u7528\u53d8\u91cf<\/h5>\n\n\n\n
#!\/bin\/bash\n# \u58f0\u660e\u53d8\u91cf\u7684\u540c\u65f6\u8d4b\u503c\nMR_FENG=shuai\n\n# \u6253\u5370\u53d8\u91cf\uff0c\u4f7f\u7528$\u53d8\u91cf\u540d\u65b9\u5f0f\u6765\u5f15\u7528\necho $MR_FENG\n\n# \u5f15\u7528\u672a\u58f0\u660e\u3001\u672a\u521d\u59cb\u5316\u7684\u53d8\u91cf\uff0c\u6ca1\u6709\u4efb\u4f55\u6253\u5370\u7684\u5185\u5bb9\u3002\u6ca1\u6709\u62a5\u9519\necho $GOOD\n<\/code><\/pre>\n\n\n\n
\u2462\u64a4\u9500\u53d8\u91cf<\/h5>\n\n\n\n
unset \u53d8\u91cf\u540d<\/p>\n\n\n\n
[root@apple ~]# USER_NAME=tom\n[root@apple ~]# echo $USER_NAME\ntom\n[root@apple ~]# unset USER_NAME\n[root@apple ~]# echo $USER_NAME\n<\/code><\/pre>\n\n\n\n
\u2463\u58f0\u660e\u5e38\u91cf<\/h5>\n\n\n\n
[root@apple ~]# readonly COMPANY_NAME=atguigu\n[root@apple ~]# echo $COMPANY_NAME\natguigu\n[root@apple ~]# COMPANY_NAME=uuu\n-bash: COMPANY_NAME: \u53ea\u8bfb\u53d8\u91cf\n[root@apple ~]# unset COMPANY_NAME\n-bash: unset: COMPANY_NAME: \u65e0\u6cd5\u53cd\u8bbe\u5b9a: \u53ea\u8bfb variable\n<\/code><\/pre>\n\n\n\n
\u4e0d\u80fd\u4fee\u6539\uff0c\u4e0d\u80fd\u64a4\u9500<\/p>\n\n\n\n
2\u3001\u8bed\u6cd5\u89c4\u5219<\/h4>\n\n\n\n
    \n
  • \u53d8\u91cf\u540d\u79f0\u53ef\u4ee5\u7531\u5b57\u6bcd\u3001\u6570\u5b57\u548c\u4e0b\u5212\u7ebf\u7ec4\u6210\uff0c\u4f46\u662f\u4e0d\u80fd\u4ee5\u6570\u5b57\u5f00\u5934\uff0c\u73af\u5883\u53d8\u91cf\u540d\u5efa\u8bae\u5927\u5199\u3002<\/li>\n\n\n\n
  • \u7b49\u53f7\u4e24\u4fa7\u4e0d\u80fd\u6709\u7a7a\u683c\uff0c\u884d\u751f\u89c4\u5219\u5c31\u662f\u53d8\u91cf\u58f0\u660e\u65f6\u5fc5\u987b\u521d\u59cb\u5316<\/li>\n\n\n\n
  • \u5728bash\u4e2d\uff0c\u53d8\u91cf\u9ed8\u8ba4\u7c7b\u578b\u90fd\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u65e0\u6cd5\u76f4\u63a5\u8fdb\u884c\u6570\u503c\u8fd0\u7b97\u3002<\/li>\n\n\n\n
  • \u53d8\u91cf\u7684\u503c\u5982\u679c\u6709\u7a7a\u683c\uff0c\u9700\u8981\u4f7f\u7528\u53cc\u5f15\u53f7\u6216\u5355\u5f15\u53f7\u62ec\u8d77\u6765\u3002<\/li>\n\n\n\n
  • \u53d8\u91cf\u540d\u533a\u5206\u5927\u5c0f\u5199\u3002<\/li>\n<\/ul>\n\n\n\n
    \u56db\u3001\u7279\u6b8a\u53d8\u91cf<\/h3>\n\n\n\n
    1\u3001$n<\/h4>\n\n\n\n
    n\u662f\u6570\u5b57\uff0c$0\u4ee3\u8868\u5f53\u524d\u811a\u672c\u540d\u79f0\u3002\u4ece1\u5f00\u59cb\u8868\u793a\u811a\u672c\u63a5\u6536\u5230\u7684\u7b2cn\u4e2a\u53c2\u6570\u3002\u4ece{10}\u5f00\u59cb\u6570\u5b57\u9700\u8981\u4f7f\u7528{}\u62ec\u8d77\u6765\u3002<\/p>\n\n\n\n
    [root@hadoop101 datas]$ touch parameter.sh \n[root@hadoop101 datas]$ vim parameter.sh\n\n#!\/bin\/bash\necho \"$0  $1   $2\"\n\n[root@hadoop101 datas]$ chmod 777 parameter.sh\n\n[root@hadoop101 datas]$ .\/parameter.sh cls  xz\n.\/parameter.sh  cls   xz\n<\/code><\/pre>\n\n\n\n
    2\u3001$#<\/h4>\n\n\n\n
    \u8fd4\u56de\u8f93\u5165\u53c2\u6570\u7684\u4e2a\u6570<\/p>\n\n\n\n
    [root@hadoop101 datas]$ vim parameter.sh\n\n#!\/bin\/bash\necho \"$0  $1   $2\"\necho $#\n\n[root@hadoop101 datas]$ chmod 777 parameter.sh\n\n[root@hadoop101 datas]$ .\/parameter.sh cls  xz\nparameter.sh cls xz \n2\n<\/code><\/pre>\n\n\n\n
    3\u3001*\u548c@<\/h4>\n\n\n\n
    \u90fd\u80fd\u591f\u8fd4\u56de\u5168\u90e8\u53c2\u6570\uff0c\u53ea\u6709\u5728\u5faa\u73af\u4e2d\u4e14\u653e\u5728\u5f15\u53f7\u4e2d\u80fd\u591f\u4f53\u73b0\u51fa\u5b83\u4eec\u7684\u533a\u522b\u3002<\/p>\n\n\n\n
    [root@hadoop101 datas]$ vim parameter.sh\n\n#!\/bin\/bash\necho \"$0  $1   $2\"\necho $#\necho $*\necho $@\n\n[root@hadoop101 datas]$ bash parameter.sh 1 2 3\nparameter.sh  1   2\n3\n1 2 3\n1 2 3\n<\/code><\/pre>\n\n\n\n
    4\u3001$?<\/h4>\n\n\n\n
    \u8fd4\u56de\u4e0a\u4e00\u6761\u547d\u4ee4\u7684\u6267\u884c\u7ed3\u679c\u3002<\/p>\n\n\n\n
      \n
    • \u6761\u4ef6\u5224\u65ad\u8bed\u53e5\n
        \n
      • \u8fd4\u56de 0 \u8868\u793a true<\/li>\n\n\n\n
      • \u8fd4\u56de 1 \u8868\u793a false<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • \u666e\u901a\u8bed\u53e5\n
          \n
        • \u8fd4\u56de 0 \u8868\u793a\u6210\u529f<\/li>\n\n\n\n
        • \u8fd4\u56de\u975e 0 \u6570\u8868\u793a\u5931\u8d25<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
          #!\/bin\/bash\n# \u628a\u8fd0\u884c\u5f53\u524d\u811a\u672c\u7684\u7a0b\u5e8f\u540d\u79f0\u8f93\u51fa\necho \"\u8fd0\u884c\u5f53\u811a\u672c\u7684\u7a0b\u5e8f\u540d\u79f0\uff1a$0\"\n\n# \u628a\u8fd0\u884c\u5f53\u524d\u811a\u672c\u65f6\u4f20\u5165\u7684\u53c2\u6570\u8f93\u51fa\necho \"\u7b2c\u4e00\u4e2a\u53c2\u6570\uff1a$1\"\necho \"\u7b2c\u4e8c\u4e2a\u53c2\u6570\uff1a$2\"\necho \"\u7b2c\u4e09\u4e2a\u53c2\u6570\uff1a$3\"\n\n# \u6570\u5b57\u662f\u4e24\u4f4d\u6570\u65f6\u9700\u8981\u5e26\u4e0a\u5927\u62ec\u53f7\necho \"\u7b2c\u5341\u4e2a\u53c2\u6570\uff1a${10}\"\n\n# \u8f93\u51fa\u4f20\u5165\u53c2\u6570\u7684\u4e2a\u6570\necho \"\u4f20\u5165\u53c2\u6570\u7684\u4e2a\u6570\uff1a$#\"\n\n# \u8f93\u51fa\u5168\u90e8\u53c2\u6570\necho \"\u5168\u90e8\u53c2\u6570\u5217\u8868\uff1a$*\"\necho \"\u5168\u90e8\u53c2\u6570\u5217\u8868\uff1a$@\"\n\n# \u8f93\u51fa\u4e0a\u4e00\u6761\u547d\u4ee4\u6267\u884c\u7684\u7ed3\u679c\necho \"\u4e0a\u4e00\u6b65\u64cd\u4f5c\uff1a$?\"\n\n# \u4eba\u4e3a\u5236\u9020\u4e00\u4e2a\u95ee\u9898\nshuai\n\necho \"\u4e0a\u4e00\u6b65\u64cd\u4f5c\uff1a$?\"\n\n<\/code><\/pre>\n\n\n\n
          \u7b2c\u56db\u8282 \u8868\u8fbe\u5f0f<\/h2>\n\n\n\n
          ((\u8868\u8fbe\u5f0f))\u6216[\u8868\u8fbe\u5f0f]<\/p>\n\n\n\n
          [root@apple ~]# echo $((20+30))\n50\n[root@apple ~]# echo $(((15+15)*2))\n60\n[root@apple ~]# echo $[(15+15)*2]\n60\n<\/code><\/pre>\n\n\n\n
          \u7b2c\u4e94\u8282 \u6761\u4ef6\u5224\u65ad<\/h2>\n\n\n\n
          \u4e00\u3001\u57fa\u672c\u8bed\u6cd5<\/h3>\n\n\n\n
            \n
          • \u5199\u6cd51\uff1atest condition<\/li>\n\n\n\n
          • \u5199\u6cd52\uff1a[ condition ]\n
              \n
            • \u6ce8\u610f condition \u524d\u540e\u6709\u7a7a\u683c<\/li>\n\n\n\n
            • \u7a7a\u5b57\u7b26\u4e32\u89c6\u4e3a false\uff0c\u975e\u7a7a\u5b57\u7b26\u4e32\u89c6\u4e3a true<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n
              \u4e8c\u3001\u5e38\u7528\u6761\u4ef6\u5224\u65ad<\/h3>\n\n\n\n
              \u6570\u636e\u7c7b\u578b<\/th>\u5199\u6cd5<\/th>\u5355\u8bcd<\/th>\u542b\u4e49<\/th><\/tr><\/thead>
              \u6570\u503c<\/td>-lt<\/td>less than<\/td>\u5c0f\u4e8e<\/td><\/tr>
              \u6570\u503c<\/td>-le<\/td>less equal<\/td>\u5c0f\u4e8e\u7b49\u4e8e<\/td><\/tr>
              \u6570\u503c<\/td>-eq<\/td>equal<\/td>\u7b49\u4e8e<\/td><\/tr>
              \u6570\u503c<\/td>-gt<\/td>greater than<\/td>\u5927\u4e8e<\/td><\/tr>
              \u6570\u503c<\/td>-ge<\/td>greater equal<\/td>\u5927\u4e8e\u7b49\u4e8e<\/td><\/tr>
              \u6570\u503c<\/td>-ne<\/td>not equal<\/td>\u4e0d\u7b49\u4e8e<\/td><\/tr>
              \u6587\u4ef6<\/td>-r<\/td>read<\/td>\u5224\u65ad\u5f53\u524d\u7528\u6237\u662f\u5426\u53ef\u4ee5\u8bfb\u53d6\u8be5\u6587\u4ef6<\/td><\/tr>
              \u6587\u4ef6<\/td>-w<\/td>write<\/td>\u5224\u65ad\u5f53\u524d\u7528\u6237\u662f\u5426\u53ef\u4ee5\u4fee\u6539\u8be5\u6587\u4ef6<\/td><\/tr>
              \u6587\u4ef6<\/td>-x<\/td>execute<\/td>\u5224\u65ad\u5f53\u524d\u7528\u6237\u5bf9\u8be5\u6587\u4ef6\u662f\u5426\u6709\u6267\u884c\u6743\u9650<\/td><\/tr>
              \u6587\u4ef6<\/td>-f<\/td>file<\/td>\u5224\u65ad\u5f53\u524d\u6587\u4ef6\u662f\u5426\u5b58\u5728\u5e76\u4e14\u662f\u4e00\u4e2a\u5e38\u89c4\u7684\u6587\u4ef6<\/td><\/tr>
              \u6587\u4ef6<\/td>-e<\/td>existence<\/td>\u5224\u65ad\u6587\u4ef6\u662f\u5426\u5b58\u5728<\/td><\/tr>
              \u6587\u4ef6<\/td>-d<\/td>directory<\/td>\u5224\u65ad\u662f\u5426\u5b58\u5728\u5e76\u4e14\u662f\u4e00\u4e2a\u76ee\u5f55<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
              \u53ef\u4ee5\u53c2\u8003\u4e0b\u9762\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
              #!\/bin\/bash\n\n# \u6761\u4ef6\u5224\u65ad\u8868\u8fbe\u5f0f\u5199\u6cd5\u4e00\uff1atest\ntest 10 -gt 7\n\n# \u4f7f\u7528$?\u83b7\u53d6\u4e0a\u4e00\u6761\u8bed\u53e5\u7684\u6267\u884c\u7ed3\u679c\necho $?\n\n# \u4f7f\u7528$?\u83b7\u53d6\u4e0a\u4e00\u6761\u8bed\u53e5\u7684\u6267\u884c\u7ed3\u679c\ntest 10 -lt 7\necho $?\n\n# \u6761\u4ef6\u5224\u65ad\u8868\u8fbe\u5f0f\u5199\u6cd5\u4e8c\uff1a[ condition ]\n# \u6ce8\u610f\uff1acondition\u4e24\u8fb9\u8981\u6709\u7a7a\u683c\n[ 10 -gt 7 ]\necho $?\n\n[ 10 -lt 7 ]\necho $?\n\n# \u4e13\u95e8\u9488\u5bf9\u6587\u4ef6\u8fdb\u884c\u64cd\u4f5c\u7684\u8fd0\u7b97\u7b26\n[ -e aaa.txt ]\necho $?\n\n[ -r aaa.txt ]\necho $?\n\n[ -w aaa.txt ]\necho $?\n<\/code><\/pre>\n\n\n\n
              \u7b2c\u516d\u8282 \u6d41\u7a0b\u63a7\u5236<\/h2>\n\n\n\n
              \u4e00\u3001\u4e09\u76ee\u8fd0\u7b97\u7b26<\/h3>\n\n\n\n
              [root@apple w]# [ 10 -gt 5 ] && echo \"10\u5927\u4e8e5\" || echo \"10\u5c0f\u4e8e5\"\n10\u5927\u4e8e5\n<\/code><\/pre>\n\n\n\n
              \u4e8c\u3001if\u5224\u65ad<\/h3>\n\n\n\n
              \u6ce8\u610f\uff1aif\u540e\u9762\u6709\u7a7a\u683c<\/p>\n\n\n\n
              1\u3001\u5355if<\/h4>\n\n\n\n
              if [ 10 -gt 5 ]\nthen\necho \"10\u5927\u4e8e5\"\nfi\n\n<\/code><\/pre>\n\n\n\n
              2\u3001if…else<\/h4>\n\n\n\n
              if [ 10 -gt 5 ]\nthen\necho \"10\u5927\u4e8e5\"\nelse\necho \"10\u5c0f\u4e8e5\"\nfi\n<\/code><\/pre>\n\n\n\n
              3\u3001if…elif<\/h4>\n\n\n\n
              if [ 10 -gt 5 ]\nthen\necho \"10\u5927\u4e8e5\"\nelif [ 10 -lt 5 ]\nthen\necho \"10\u5c0f\u4e8e5\"\nelse\necho \"10\u7b49\u4e8e5\"\nfi\n<\/code><\/pre>\n\n\n\n
              \u4e09\u3001case\u5224\u65ad<\/h3>\n\n\n\n
              AGE=10\ncase $AGE in\n\"10\")\necho 10\n;;\n\"20\")\necho 20\n;;\n*)\necho other\n;;\nesac\n<\/code><\/pre>\n\n\n\n
              \"\"<\/div><\/figure>\n\n\n\n
              \u56db\u3001for\u5faa\u73af<\/h3>\n\n\n\n
              1\u3001\u5e38\u89c4\u7528\u6cd5<\/h4>\n\n\n\n
              for (( i=1;i<=10;i++ ))\ndo\necho $i\ndone\n<\/code><\/pre>\n\n\n\n
              2\u3001\u904d\u5386\u5916\u90e8\u6570\u636e<\/h4>\n\n\n\n
              #!\/bin\/bash\n# \u5982\u679c\u9700\u8981\u4f7f\u7528\u5916\u90e8\u6570\u636e\uff0c\u5219\u9700\u8981\u628a\u5916\u90e8\u6570\u636e\u8d4b\u503c\u7ed9\u4e00\u4e2a\u53d8\u91cf\uff0c\u4e0d\u80fd\u5728for\u8bed\u53e5\u4e2d\u76f4\u63a5\u4f7f\u7528\nlen=$1\n\nfor (( i=1;i<=len;i++ ))\n\n# \u4ecedo\u5173\u952e\u5b57\u5f00\u59cb\u662f\u5faa\u73af\u4f53\u5f00\u59cb\ndo\n\necho $i;\n\n# \u5230done\u5173\u952e\u5b57\u4e3a\u6b62\u662f\u5faa\u73af\u4f53\u7ed3\u675f\ndone\n<\/code><\/pre>\n\n\n\n
              3\u3001for…in\u5faa\u73af<\/h4>\n\n\n\n
              for i in $*\ndo\necho $i\ndone\n<\/code><\/pre>\n\n\n\n
              \u6ca1\u6709\u5f15\u53f7\u7684\u65f6\u5019*\u548c@\u4e00\u6837\uff0c\u52a0\u4e86\u5f15\u53f7\u5c31\u6709\u533a\u522b<\/p>\n\n\n\n
              for i in \"$*\"\ndo\necho $i\ndone\n<\/code><\/pre>\n\n\n\n
              \u4e0a\u9762\u4ee3\u7801\u8f93\u51fa\u7684\u7ed3\u679c\u662f\uff1a<\/p>\n\n\n\n
              [root@apple w]# sh shell42.sh a b c d e\na b c d e\n<\/code><\/pre>\n\n\n\n
              \u201c*\u201d\u6ca1\u6709\u6362\u884c\uff0c\u201c@\u201d\u6709\u6362\u884c<\/p>\n\n\n\n
              \u4e94\u3001while\u5faa\u73af<\/h3>\n\n\n\n
              s=0\ni=1\nwhile [ $i -le 100 ]\ndo\n        s=$[$s+$i]\n        i=$[$i+1]\ndone\n\necho $s\n<\/code><\/pre>\n\n\n\n
              \u7b2c\u4e03\u8282 \u51fd\u6570<\/h2>\n\n\n\n
              \u4e00\u3001\u6982\u8ff0<\/h3>\n\n\n\n
              Shell \u7f16\u7a0b\u4e2d\u7684\u51fd\u6570\u548c\u6211\u4eec\u4ee5\u524d\u719f\u6089\u7684\u51fd\u6570\u6700\u5927\u7684\u533a\u522b\u662f\uff1aShell \u7f16\u7a0b\u4e2d\u8981\u6c42\u51fd\u6570\u7684\u8fd4\u56de\u503c\u53ea\u80fd\u662f\u6574\u6570\u3002\u5e76\u4e14\u53ea\u80fd\u901a\u8fc7 $? \u65b9\u5f0f\u83b7\u5f97\u3002\u53ef\u4ee5\u663e\u793a\u52a0\uff1areturn \u8fd4\u56de\uff0c\u5982\u679c\u4e0d\u52a0\uff0c\u5c06\u4ee5\u6700\u540e\u4e00\u6761\u547d\u4ee4\u8fd0\u884c\u7ed3\u679c\uff0c\u4f5c\u4e3a\u8fd4\u56de\u503c\u3002return \u540e\u8ddf\u6570\u503c n(0-255)\u3002<\/p>\n\n\n\n
              # \u58f0\u660e\u51fd\u6570\nfunction sum() {\n    echo $[$1+$2]\n}\n\n# \u8c03\u7528\u51fd\u6570\nsum 10 20\n<\/code><\/pre>\n\n\n\n
              \u5728\u51fd\u6570\u4f53\u4e2d\uff0c$1\u3001$2\u7b49\u662f\u5bf9\u51fd\u6570\u53c2\u6570\u7684\u5f15\u7528\u3002<\/p>\n\n\n\n
              #!\/bin\/bash\n# \u58f0\u660e\u51fd\u6570\nfunction sum(){\n  # \u4f7f\u7528$1\u3001$2\u5f15\u7528\u51fd\u6570\u4f20\u5165\u7684\u53c2\u6570\n  return $[$1+$2]\n}\n\n# \u8c03\u7528\u51fd\u6570\uff0c\u4f20\u5165\u53c2\u6570\nsum 10 20\n\n# \u4f7f\u7528$?\u83b7\u53d6\u51fd\u6570\u6267\u884c\u7ed3\u679c\necho \"sum 10 20\u6267\u884c\u7684\u7ed3\u679c\u662f$?\"\n<\/code><\/pre>\n\n\n\n
              \u4e8c\u3001\u83b7\u53d6\u5916\u90e8\u6570\u636e<\/h3>\n\n\n\n
              1\u3001\u83b7\u53d6\u53c2\u6570<\/h4>\n\n\n\n
              \u8fd9\u4e2a\u524d\u9762\u8bf4\u8fc7\u4e86\uff0c\u901a\u8fc7$1\u30012\u7b49\u65b9\u5f0f\u83b7\u53d6\u51fd\u6570\u53c2\u6570\uff0c{10}\u5f00\u59cb\u9700\u8981\u4f7f\u7528\u5927\u62ec\u53f7\u3002<\/p>\n\n\n\n
              2\u3001\u4f7f\u7528read\u8bfb\u53d6\u7528\u6237\u8f93\u5165<\/h4>\n\n\n\n
              read\u547d\u4ee4\u6709\u4e24\u4e2a\u5e38\u7528\u53c2\u6570<\/p>\n\n\n\n
                \n
              • -t\u7528\u4e8e\u6307\u5b9a\u8f93\u5165\u7b49\u5f85\u65f6\u95f4\uff0c\u5355\u4f4d\u662f\u79d2<\/li>\n\n\n\n
              • -p\u7528\u4e8e\u6307\u5b9a\u63d0\u793a\u6587\u5b57<\/li>\n<\/ul>\n\n\n\n
                read -t 10 -p \"please enter:\" NAME\necho $NAME\n<\/code><\/pre>\n\n\n\n
                \u4e09\u3001\u5c0f\u7ec3\u4e60<\/h3>\n\n\n\n
                #!\/bin\/bash\n# \u7528\u6237\u8f93\u5165\u6570\u5b57\uff0c\u5224\u65ad\u662f\u5426\u4e3a7\u7684\u500d\u6570\n# \u521d\u6b65\u8bfb\u53d6\u7528\u6237\u662f\u5426\u7ee7\u7eed\u73a9\u7684\u6307\u4ee4\nread -t 10 -p \"\u8bf7\u8f93\u5165\u6570\u5b57\u6307\u4ee4\uff080\u4ee3\u8868\u7ee7\u7eed\u73a9\uff0c1\u4ee3\u8868\u9000\u51fa\uff09\uff1a\" code\n\n# \u5faa\u73af\u8be2\u95ee\u7528\u6237\u662f\u5426\u7ee7\u7eed\u73a9\nwhile [ $code -ne 1 ]\n\n# \u8fdb\u5165\u5faa\u73af\u4f53\ndo\n\n# \u8bfb\u53d6\u7528\u6237\u8f93\u5165\u7684\u6570\u636e\nread -t 10 -p \"\u8bf7\u8f93\u5165\u6570\u5b57\uff1a\" number\n\n# \u5224\u65ad\u6570\u636e\u662f\u5426\u4e3a7\u7684\u6574\u6570\u500d\nif [ $[$number%7] -eq 0 ]\n\n# \u8fdb\u5165if\u5206\u652f\nthen\n# \u6267\u884cif\u5206\u652f\necho \"$number\u662f7\u7684\u500d\u6570\u3002\"\n# \u8fdb\u5165else\u5206\u652f\nelse\n# \u6267\u884celse\u5206\u652f\necho \"$number\u4e0d\u662f7\u7684\u500d\u6570\u3002\"\n# \u7ed3\u675fif\u7ed3\u6784\nfi\n\n# \u518d\u6b21\u8bfb\u53d6\u7528\u6237\u662f\u5426\u7ee7\u7eed\u73a9\u7684\u6307\u4ee4\nread -t 10 -p \"\u8bf7\u8f93\u5165\u6570\u5b57\u6307\u4ee4\uff080\u4ee3\u8868\u7ee7\u7eed\u73a9\uff0c1\u4ee3\u8868\u9000\u51fa\uff09\uff1a\" code\n\n# \u7ed3\u675f\u5faa\u73af\u4f53\ndone\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
                \u7b2c\u4e00\u8282 Shell\u7f16\u7a0b\u6982\u8ff0 Shell\u662f\u4e00\u4e2a\u547d\u4ee4\u884c\u89e3\u91ca\u5668\uff0c\u5b83\u63a5\u6536\u5e94\u7528\u7a0b\u5e8f\u6216\u7528\u6237\u7684\u547d\u4ee4\uff0c\u7136\u540e\u8c03\u7528\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u3002  […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[67],"tags":[51],"class_list":["post-3484","post","type-post","status-publish","format-standard","hentry","category-linux-code","tag-linux"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/3484"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3484"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/3484\/revisions"}],"predecessor-version":[{"id":3491,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/3484\/revisions\/3491"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3484"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}