transform command: cat

core/src/main/java/com/taobao/arthas/core/command/basic1000/CatCommand.java

@@ -5,6 +5,7 @@ import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.List;
 
+import com.taobao.arthas.core.command.model.CatModel;
 import com.alibaba.arthas.deps.org.slf4j.Logger;
 import com.alibaba.arthas.deps.org.slf4j.LoggerFactory;
 import com.taobao.arthas.core.shell.cli.Completion;
@@ -24,6 +25,8 @@ public class CatCommand extends AnnotatedCommand {
     private static final Logger logger = LoggerFactory.getLogger(CatCommand.class);
     private List<String> files;
     private String encoding;
+    private Integer sizeLimit = 128 * 1024;
+    private int maxSizeLimit = 8 * 1024 * 1024;
 
     @Argument(argName = "files", index = 0)
     @Description("files")
@@ -37,37 +40,43 @@ public class CatCommand extends AnnotatedCommand {
         this.encoding = encoding;
     }
 
+    @Option(shortName = "M", longName = "sizeLimit")
+    @Description("Upper size limit in bytes for the result (128 * 1024 by default, the maximum value is 8 * 1024 * 1024)")
+    public void setSizeLimit(Integer sizeLimit) {
+        this.sizeLimit = sizeLimit;
+    }
+
     @Override
     public void process(CommandProcess process) {
+        if (!verifyOptions(process)) {
+            return;
+        }
+
         for (String file : files) {
             File f = new File(file);
             if (!f.exists()) {
-                process.write("cat " + file + ": No such file or directory\n");
-                process.end();
+                process.end(-1, "cat " + file + ": No such file or directory");
                 return;
             }
             if (f.isDirectory()) {
-                process.write("cat " + file + ": Is a directory\n");
-                process.end();
+                process.end(-1, "cat " + file + ": Is a directory");
                 return;
             }
         }
 
         for (String file : files) {
             File f = new File(file);
-            if (f.length() > 1024 * 1024 * 8) {
-                process.write("cat " + file + ": Is to large, size: " + f.length() + '\n');
-                process.end();
+            if (f.length() > sizeLimit) {
+                process.end(-1, "cat " + file + ": Is too large, size: " + f.length());
                 return;
             }
             try {
                 String fileToString = FileUtils.readFileToString(f,
-                                encoding == null ? Charset.defaultCharset() : Charset.forName(encoding));
-                process.write(fileToString);
+                        encoding == null ? Charset.defaultCharset() : Charset.forName(encoding));
+                process.appendResult(new CatModel(file, fileToString));
             } catch (IOException e) {
                 logger.error("cat read file error. name: " + file, e);
-                process.write("cat read file error: " + e.getMessage() + '\n');
-                process.end(1);
+                process.end(1, "cat read file error: " + e.getMessage());
                 return;
             }
         }
@@ -75,6 +84,22 @@ public class CatCommand extends AnnotatedCommand {
         process.end();
     }
 
+    private boolean verifyOptions(CommandProcess process) {
+        if (sizeLimit > maxSizeLimit) {
+            process.end(-1, "sizeLimit cannot be large than: " + maxSizeLimit);
+            return false;
+        }
+
+        //目前不支持过滤，限制http请求执行的文件大小
+        int maxSizeLimitOfHttp = 128 * 1024;
+        boolean isHttpApiRequest = !process.session().isTty();
+        if (isHttpApiRequest && sizeLimit > maxSizeLimitOfHttp) {
+            process.end(-1, "When executing commands with http, sizeLimit cannot be large than: " + maxSizeLimitOfHttp);
+            return false;
+        }
+        return true;
+    }
+
     @Override
     public void complete(Completion completion) {
         if (!CompletionUtils.completeFilePath(completion)) {

core/src/main/java/com/taobao/arthas/core/command/model/CatModel.java

@@ -0,0 +1,49 @@
+package com.taobao.arthas.core.command.model;
+
+/**
+ * Result model for CatCommand
+ * @author gongdewei 2020/5/11
+ */
+public class CatModel extends ResultModel implements Countable {
+
+    private String file;
+    private String content;
+
+    public CatModel() {
+    }
+
+    public CatModel(String file, String content) {
+        this.file = file;
+        this.content = content;
+    }
+
+    @Override
+    public String getType() {
+        return "cat";
+    }
+
+    public String getFile() {
+        return file;
+    }
+
+    public void setFile(String file) {
+        this.file = file;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    @Override
+    public int size() {
+        if (content != null) {
+            //粗略计算行数作为item size
+            return content.length()/100 + 1;
+        }
+        return 0;
+    }
+}

core/src/main/java/com/taobao/arthas/core/command/view/CatView.java

@@ -0,0 +1,17 @@
+package com.taobao.arthas.core.command.view;
+
+import com.taobao.arthas.core.command.model.CatModel;
+import com.taobao.arthas.core.shell.command.CommandProcess;
+
+/**
+ * Result view for CatCommand
+ * @author gongdewei 2020/5/11
+ */
+public class CatView extends ResultView<CatModel> {
+
+    @Override
+    public void draw(CommandProcess process, CatModel result) {
+        process.write(result.getContent()).write("\n");
+    }
+
+}

core/src/main/java/com/taobao/arthas/core/command/view/ResultViewResolver.java

@@ -38,6 +38,7 @@ public class ResultViewResolver {
             registerView(new HelpModel(), new HelpView());
             //registerView(new HistoryModel(), new HistoryView());
             registerView(new EchoModel(), new EchoView());
+            registerView(new CatModel(), new CatView());
         } catch (Throwable e) {
             logger.error("register result view failed", e);
         }