java编写shell命令解析规则

梦里梦外; 2022-09-07 12:10 89阅读 0赞

因业务需求，要对shell命令添加一个白名单，因此需要对shell进行一个简单的解析，代码跑了两天基本满足现阶段要求，代码如下：

public static void main(String[] args) { 
    		System.out.println(checkCmd("zgrep oHQwN0ZYayuTyNZHAosTKc7uP6vk $logpath | grep -o \"cmd=[^ ]*\" | sort | uniq -c".trim()));
    	}
    
        public static boolean checkCmd(String grep) { 
    		List<List<String>> unitList = new ArrayList<>();
    		List<String> tokenList = new ArrayList<>();
    		boolean flag = false;
    		char punc = '~';
    		StringBuilder sb = new StringBuilder();
    		int pre = 0, i;
    		for (i = 0; i < grep.length() && pre < grep.length(); i++) { 
    			char c = grep.charAt(i);
    			if (flag) { 
    				if (c == punc) { 
    					flag = false;
    					tokenList.add(grep.substring(pre + 1, i));
    					pre = i + 1;
    				}
    			} else { 
    				if (c == ' ' || c == '|') { 
    					tokenList.add(grep.substring(pre, i));
    					pre = i + 1;
    					if (c == '|') { 
    						unitList.add(new ArrayList<>(tokenList));
    						tokenList.clear();
    					}
    				} else if ((c == '\'' || c == '"') && !flag) { 
    					flag = true;
    					punc = c;
    				}
    			}
    		}
    		if (pre < grep.length()) { 
    			tokenList.add(grep.substring(pre, i));
    			unitList.add(new ArrayList<>(tokenList));
    		}
    		//拿到白名单
    		List<String> wightTokenList = Utils.getTokenWightList();
    		for (List<String> list : unitList) { 
    			List<String> tokens = list.stream().filter(s -> !s.trim().equals("")).collect(Collectors.toList());
    			if (!wightTokenList.contains(tokens.get(0)) || !legalPath(tokens)) { 
    				return false;
    			}
    		}
    		return true;
        }
    
    	private static boolean legalPath(List<String> tokens) { 
    		if (tokens.get(0).equals("less") || tokens.get(0).equals("cat") || tokens.get(0).equals("nl")) { 
    			String last = tokens.get(tokens.size() - 1);
    			if (last.indexOf("/") > -1) { 
    				return false;
    			}
    		}
    		return true;
    	}