{"id":106,"date":"2025-06-24T14:49:35","date_gmt":"2025-06-24T06:49:35","guid":{"rendered":"http:\/\/1.14.207.80\/?p=106"},"modified":"2025-06-24T14:50:12","modified_gmt":"2025-06-24T06:50:12","slug":"linux%e5%9f%ba%e7%a1%80%ef%bc%88shell%e8%84%9a%e6%9c%ac%e8%bf%9b%e9%98%b6%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.zhangjianjia.xyz\/index.php\/2025\/06\/24\/linux%e5%9f%ba%e7%a1%80%ef%bc%88shell%e8%84%9a%e6%9c%ac%e8%bf%9b%e9%98%b6%ef%bc%89\/","title":{"rendered":"Linux\u57fa\u7840\uff08SHELL\u811a\u672c\u8fdb\u9636\uff09"},"content":{"rendered":"\n

Shell \u811a\u672c\u7f16\u7a0b\uff1a\u5faa\u73af\u4e0e\u51fd\u6570<\/h1>\n

\u4e00\u3001while \u5faa\u73af<\/h2>\n

\u5728 Linux shell \u811a\u672c\u4e2d\uff0cwhile \u5faa\u73af\u662f\u4e00\u79cd\u57fa\u672c\u7684\u63a7\u5236\u6d41\u7ed3\u6784\uff0c\u5b83\u5141\u8bb8\u91cd\u590d\u6267\u884c\u4e00\u6bb5\u4ee3\u7801\uff0c\u76f4\u5230\u6307\u5b9a\u7684\u6761\u4ef6\u4e0d\u518d\u6ee1\u8db3\u4e3a\u6b62\u3002\u9002\u7528\u4e8e\u4e8b\u5148\u4e0d\u77e5\u9053\u9700\u8981\u5faa\u73af\u591a\u5c11\u6b21\uff0c\u4f46\u77e5\u9053\u4f55\u65f6\u505c\u6b62\u7684\u60c5\u51b5\u3002<\/p>\n

\u57fa\u672c\u8bed\u6cd5<\/h3>\n
while [ \u6761\u4ef6\u8868\u8fbe\u5f0f ]\ndo\n  # \u6267\u884c\u547d\u4ee4\ndone\n<\/code><\/pre>\n
\u793a\u4f8b<\/h3>\n
\u793a\u4f8b 1\uff1a\u6253\u5370\u6570\u5b57 1 \u5230 5<\/h4>\n
#!\/bin\/bash\ncounter=1\nwhile [ $counter -le 5 ]\ndo\n  echo "The number is $counter"\n  ((counter++))\ndone\n<\/code><\/pre>\n
\u793a\u4f8b 2\uff1a\u8bfb\u53d6\u6587\u4ef6\u5185\u5bb9<\/h4>\n
#!\/bin\/bash\nwhile IFS= read -r line\ndo\n  echo "$line"\ndone < "filename.txt"\n<\/code><\/pre>\n
\u793a\u4f8b 3\uff1a\u65e0\u9650\u5faa\u73af<\/h4>\n
#!\/bin\/bash\nwhile true\ndo\n  echo "This is an infinite loop."\n  sleep 1\ndone\n<\/code><\/pre>\n
\u6ce8\u610f\u4e8b\u9879<\/h3>\n
    \n
  • \u786e\u4fdd\u6761\u4ef6\u8868\u8fbe\u5f0f\u903b\u8f91\u6b63\u786e\uff0c\u907f\u514d\u65e0\u9650\u5faa\u73af<\/li>\n
  • \u5904\u7406\u6587\u4ef6\u65f6\u4f7f\u7528 IFS=<\/code> \u548c -r<\/code> \u9009\u9879\u907f\u514d\u610f\u5916\u884c\u4e3a<\/li>\n
  • \u5728\u5faa\u73af\u4e2d\u9002\u5f53\u66f4\u65b0\u6761\u4ef6\u53d8\u91cf\uff0c\u786e\u4fdd\u5faa\u73af\u6700\u7ec8\u505c\u6b62<\/li>\n<\/ul>\n
    \u4e24\u79cd\u6b7b\u5faa\u73af\u5199\u6cd5<\/h3>\n
    # \u5199\u6cd5 1\nwhile true; do\n  # commands\ndone\n\n# \u5199\u6cd5 2\nwhile :; do\n  # commands\ndone\n<\/code><\/pre>\n
    while read \u8bed\u6cd5\uff08\u9010\u884c\u5904\u7406\uff09<\/h3>\n
    while read \u53d8\u91cf; do\n  # \u5904\u7406\u903b\u8f91\ndone\n<\/code><\/pre>\n
    \n
    \u4e8c\u3001until \u5faa\u73af<\/h2>\n
    until \u5faa\u73af\u6301\u7eed\u6267\u884c\u5faa\u73af\u4f53\u5185\u7684\u4ee3\u7801\uff0c\u76f4\u5230\u7ed9\u5b9a\u6761\u4ef6\u4e3a\u771f\u65f6\u505c\u6b62\uff08\u4e0e while \u5faa\u73af\u76f8\u53cd\uff09\u3002<\/p>\n
    \u5b9a\u4e49\u4e0e\u7279\u70b9<\/h3>\n
      \n
    • \u5b9a\u4e49<\/strong>\uff1a\u6301\u7eed\u6267\u884c\u76f4\u5230\u6761\u4ef6\u4e3a\u771f<\/li>\n
    • \u7279\u70b9<\/strong>\uff1a\n
        \n
      • \u65e0\u9700\u77e5\u9053\u5177\u4f53\u5faa\u73af\u6b21\u6570<\/li>\n
      • \u5f53\u6761\u4ef6\u6ee1\u8db3\u65f6\u81ea\u52a8\u505c\u6b62<\/li>\n
      • \u5728 Ruby\u3001Bash \u7b49\u8bed\u8a00\u4e2d\u5e7f\u6cdb\u5e94\u7528<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
        \u8bed\u6cd5\u7ed3\u6784<\/h3>\n
        # \u683c\u5f0f 1\nuntil [ condition ]\ndo\n  # \u6267\u884c\u7684\u547d\u4ee4\ndone\n\n# \u683c\u5f0f 2\nuntil (( condition ))\ndo\n  # \u6267\u884c\u7684\u547d\u4ee4\ndone\n<\/code><\/pre>\n
        \u5de5\u4f5c\u539f\u7406<\/h3>\n
          \n
        1. \u6bcf\u6b21\u8fed\u4ee3\u5f00\u59cb\u65f6\u68c0\u67e5\u6761\u4ef6<\/li>\n
        2. \u6761\u4ef6\u4e3a\u5047\uff08\u8fd4\u56de 0\uff09\u65f6\u6267\u884c\u5faa\u73af\u4f53<\/li>\n
        3. \u6761\u4ef6\u4e3a\u771f\uff08\u8fd4\u56de\u975e 0\uff09\u65f6\u9000\u51fa\u5faa\u73af<\/li>\n<\/ol>\n
          \u793a\u4f8b<\/h3>\n
          \u793a\u4f8b 1\uff1a\u6253\u5370\u6570\u5b57 1 \u5230 5<\/h4>\n
          #!\/bin\/bash\ncount=1\nuntil [ $count -gt 5 ]\ndo\n  echo "Count: $count"\n  ((count++))\ndone\n<\/code><\/pre>\n
          \u793a\u4f8b 2\uff1a\u8ba1\u7b97 1 \u5230 100 \u7684\u603b\u548c<\/h4>\n
          #!\/bin\/bash\nall_sum=0\ni=1\nuntil ((i>100))\ndo\n  let all_sum+=i\n  let i++\ndone\necho "\u6240\u6709\u6570\u636e\u4e4b\u548c: $all_sum"\n<\/code><\/pre>\n
          \u793a\u4f8b 3\uff1a\u7b49\u5f85\u6587\u4ef6\u88ab\u521b\u5efa<\/h4>\n
          #!\/bin\/bash\nuntil [ -f \/tmp\/somefile ]\ndo\n  echo "Waiting for file to be created..."\n  sleep 2\ndone\necho "File created!"\n<\/code><\/pre>\n
          \u6ce8\u610f\u4e8b\u9879<\/h3>\n
            \n
          • \u786e\u4fdd\u9000\u51fa\u6761\u4ef6\u6b63\u786e\u4e14\u6700\u7ec8\u53ef\u8fbe<\/li>\n
          • \u4fdd\u6301\u5faa\u73af\u4f53\u7b80\u5355\uff0c\u907f\u514d\u8fc7\u5ea6\u5d4c\u5957<\/li>\n
          • \u65e0\u9650\u5faa\u73af\u9700\u786e\u4fdd\u6709\u9000\u51fa\u673a\u5236<\/li>\n<\/ul>\n
            1 \u52a0\u5230 100 \u7684\u51e0\u79cd\u5199\u6cd5<\/h3>\n
            # \u5199\u6cd5 1 (until)\nsum=0; i=1; until ((i>100)); do ((sum+=i)); ((i++)); done; echo $sum\n\n# \u5199\u6cd5 2 (while)\nsum=0; i=1; while ((i<=100)); do ((sum+=i)); ((i++)); done; echo $sum\n\n# \u5199\u6cd5 3 (for)\nsum=0; for ((i=1;i<=100;i++)); do ((sum+=i)); done; echo $sum\n<\/code><\/pre>\n
            \n
            \u4e09\u3001\u5faa\u73af\u4e2d\u65ad\u8bed\u53e5<\/h2>\n
            1. break \u547d\u4ee4<\/h3>\n
            \u7acb\u5373\u9000\u51fa\u6574\u4e2a\u5faa\u73af<\/p>\n
            for i in {1..10}; do\n  if [ $i -eq 5 ]; then\n    break\n  fi\n  echo "i is $i"\ndone\n<\/code><\/pre>\n
            2. continue \u547d\u4ee4<\/h3>\n
            \u8df3\u8fc7\u5f53\u524d\u8fed\u4ee3\uff0c\u7ee7\u7eed\u4e0b\u4e00\u6b21<\/p>\n
            for i in {1..10}; do\n  if [ $((i % 2)) -eq 0 ]; then\n    continue\n  fi\n  echo "Odd number: $i"\ndone\n<\/code><\/pre>\n
            3. exit \u547d\u4ee4<\/h3>\n
            \u9000\u51fa\u6574\u4e2a\u811a\u672c\uff08\u614e\u7528\uff09<\/p>\n
            for i in {1..10}; do\n  if [ $i -eq 5 ]; then\n    exit 0\n  fi\n  echo "i is $i"\ndone\n<\/code><\/pre>\n
            4. \u6761\u4ef6\u5224\u65ad<\/h3>\n
            \u914d\u5408 if \u8bed\u53e5\u63a7\u5236\u6d41\u7a0b<\/p>\n
            5. return \u547d\u4ee4\uff08\u51fd\u6570\u5185\u90e8\uff09<\/h3>\n
            \u9000\u51fa\u5f53\u524d\u51fd\u6570<\/p>\n
            my_function() {\n  for i in {1..10}; do\n    if [ $i -eq 5 ]; then\n      return 0\n    fi\n    echo "i is $i"\n  done\n}\n<\/code><\/pre>\n
            \n
            \u56db\u3001shift \u547d\u4ee4<\/h2>\n
            \u8c03\u6574\u4f4d\u7f6e\u53c2\u6570\u7684\u4f4d\u7f6e\uff0c\u6bcf\u6b21\u6267\u884c\u5411\u5de6\u79fb\u52a8\u53c2\u6570<\/p>\n
            \u57fa\u672c\u7528\u6cd5<\/h3>\n
            #!\/bin\/bash\necho "Original arguments: $@"\nshift\necho "After one shift: $@"\n<\/code><\/pre>\n
            \u5e26\u53c2\u6570\u7684 shift<\/h3>\n
            #!\/bin\/bash\necho "Original arguments: $@"\nshift 2\necho "After two shifts: $@"\n<\/code><\/pre>\n
            \u5faa\u73af\u4e2d\u4f7f\u7528 shift<\/h3>\n
            #!\/bin\/bash\nwhile [ $# -gt 0 ]; do\n  echo "Argument: $1"\n  shift\ndone\n<\/code><\/pre>\n
            \n
            \u4e94\u3001select \u8bed\u53e5<\/h2>\n
            \u63d0\u4f9b\u7b80\u5355\u7684\u83dc\u5355\u7cfb\u7edf\u4f9b\u7528\u6237\u9009\u62e9<\/p>\n
            \u57fa\u672c\u8bed\u6cd5<\/h3>\n
            select \u53d8\u91cf in \u9009\u9879\u5217\u8868\ndo\n  case $\u53d8\u91cf in\n    # \u5904\u7406\u903b\u8f91\n  esac\ndone\n<\/code><\/pre>\n
            \u793a\u4f8b<\/h3>\n
            #!\/bin\/bash\nPS3="\u8bf7\u9009\u62e9\u4e00\u4e2a\u9009\u9879: "\necho "\u83dc\u5355:"\nselect var in "\u9009\u98791" "\u9009\u98792" "\u9009\u98793" "\u9000\u51fa"\ndo\n  case $var in\n    "\u9009\u98791") echo "\u4f60\u9009\u62e9\u4e86\u9009\u98791" ;;\n    "\u9009\u98792") echo "\u4f60\u9009\u62e9\u4e86\u9009\u98792" ;;\n    "\u9009\u98793") echo "\u4f60\u9009\u62e9\u4e86\u9009\u98793" ;;\n    "\u9000\u51fa") echo "\u9000\u51fa\u9009\u62e9"; break ;;\n    *) echo "\u65e0\u6548\u7684\u9009\u62e9\uff0c\u8bf7\u91cd\u8bd5" ;;\n  esac\ndone\n<\/code><\/pre>\n
            \n
            \u516d\u3001\u51fd\u6570<\/h2>\n
            \u5c06\u547d\u4ee4\u5e8f\u5217\u5c01\u88c5\u4e3a\u53ef\u91cd\u7528\u4ee3\u7801\u5757<\/p>\n
            \u5b9a\u4e49\u65b9\u5f0f<\/h3>\n
            \u65b9\u5f0f 1\uff08\u63a8\u8350\uff09<\/h4>\n
            function_name() {\n  # \u51fd\u6570\u4f53\n  command1\n  command2\n}\n<\/code><\/pre>\n
            \u65b9\u5f0f 2\uff08\u7b80\u6d01\uff09<\/h4>\n
            function_name() { command1; command2; ...; }\n<\/code><\/pre>\n
            \u65b9\u5f0f 3\uff08POSIX \u6807\u51c6\uff09<\/h4>\n
            function_name {\n  command1\n  command2\n}\n<\/code><\/pre>\n
            \u51fd\u6570\u8c03\u7528<\/h3>\n
            function_name arg1 arg2 ...\n<\/code><\/pre>\n
            \u51fd\u6570\u8c03\u7528\u8def\u5f84\u5199\u6cd5<\/h3>\n
            # \u83b7\u53d6\u9879\u76ee\u6839\u8def\u5f84\nproject_root=$(pwd)\n# \u8c03\u7528\u76f8\u5bf9\u8def\u5f84\u811a\u672c\nsource "${project_root}\/path\/to\/script.sh"\n<\/code><\/pre>\n
            \u793a\u4f8b<\/h3>\n
            add_numbers() {\n  local num1=$1\n  local num2=$2\n  local sum=$((num1 + num2))\n  echo "The sum is: $sum"\n}\nadd_numbers 5 10  # \u8f93\u51fa: The sum is: 15\n<\/code><\/pre>\n
            \u6ce8\u610f\u4e8b\u9879<\/h3>\n
              \n
            1. \u4f7f\u7528 local<\/code> \u58f0\u660e\u5c40\u90e8\u53d8\u91cf<\/li>\n
            2. \u9ed8\u8ba4\u901a\u8fc7\u6807\u51c6\u8f93\u51fa\u8fd4\u56de\u7ed3\u679c<\/li>\n
            3. \u652f\u6301\u9012\u5f52\uff08\u6ce8\u610f\u6df1\u5ea6\u9650\u5236\uff09<\/li>\n
            4. \u4f7f\u7528 source<\/code> \u6216 .<\/code> \u5bfc\u5165\u51fd\u6570\u5e93<\/li>\n<\/ol>\n
              \n
              \u4e03\u3001local \u5173\u952e\u5b57<\/h2>\n
              \u58f0\u660e\u51fd\u6570\u5185\u90e8\u7684\u5c40\u90e8\u53d8\u91cf<\/p>\n
              \u793a\u4f8b<\/h3>\n
              #!\/bin\/bash\nglobal_var="Global variable"\n\nmy_function() {\n  local local_var="Local variable"\n  echo "Inside function: $global_var, $local_var"\n}\n\nmy_function\necho "Outside function: $global_var"\n# $local_var \u5728\u6b64\u4e0d\u53ef\u8bbf\u95ee\n<\/code><\/pre>\n
              \u6ce8\u610f<\/h3>\n
                \n
              • \u53ea\u80fd\u5728\u51fd\u6570\u5185\u90e8\u4f7f\u7528<\/li>\n
              • \u53d8\u91cf\u4f5c\u7528\u57df\u4ec5\u9650\u4e8e\u51fd\u6570\u5185<\/li>\n
              • \u907f\u514d\u547d\u540d\u51b2\u7a81\uff0c\u63d0\u9ad8\u53ef\u7ef4\u62a4\u6027<\/li>\n<\/ul>\n
                \n
                \u516b\u3001return \u547d\u4ee4<\/h2>\n
                \u4ece\u51fd\u6570\u8fd4\u56de\u72b6\u6001\u7801\uff080=\u6210\u529f\uff0c\u975e0=\u9519\u8bef\uff09<\/p>\n
                \u4e0e exit \u7684\u533a\u522b<\/h3>\n\n\n\n\n\n\n
                \u547d\u4ee4<\/th>\n\u4f5c\u7528\u57df<\/th>\n\u6548\u679c<\/th>\n<\/tr>\n<\/thead>\n
                return<\/td>\n\u51fd\u6570\u5185\u90e8<\/td>\n\u4ec5\u9000\u51fa\u5f53\u524d\u51fd\u6570<\/td>\n<\/tr>\n
                exit<\/td>\n\u811a\u672c\u4efb\u610f\u4f4d\u7f6e<\/td>\n\u9000\u51fa\u6574\u4e2a\u811a\u672c\u6267\u884c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
                \u793a\u4f8b<\/h3>\n
                check_file_exists() {\n  local file_path="$1"\n  if [ -e "$file_path" ]; then\n    return 0  # \u6587\u4ef6\u5b58\u5728\n  else\n    return 1  # \u6587\u4ef6\u4e0d\u5b58\u5728\n  fi\n}\n\ncheck_file_exists "\/path\/to\/file"\nif [ $? -eq 0 ]; then\n  echo "File exists"\nelse\n  echo "File not found"\nfi<\/code><\/pre>\n<\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[3],"tags":[],"class_list":["post-106","post","type-post","status-publish","format-standard","hentry","category-linux"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/posts\/106","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/comments?post=106"}],"version-history":[{"count":2,"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/posts\/106\/revisions"}],"predecessor-version":[{"id":108,"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/posts\/106\/revisions\/108"}],"wp:attachment":[{"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/media?parent=106"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/categories?post=106"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangjianjia.xyz\/index.php\/wp-json\/wp\/v2\/tags?post=106"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}