Added validate-xml sub-command

Author: skx

Diff for: README.md

@@ -294,6 +294,11 @@ Extract URLs from the named files, or STDIN.  URLs are parsed naively with a sim
 Validate JSON files for correctness and syntax-errors.
 
 
+## validate-xml
+
+Validate XML files for correctness and syntax-errors.
+
+
 ## validate-yaml
 
 Validate YAML files for correctness and syntax-errors.

Diff for: cmd_validate_xml.go

@@ -0,0 +1,192 @@
+package main
+
+import (
+	"bytes"
+	"encoding/xml"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+// Structure for our options and state.
+type validateXMLCommand struct {
+
+	// comma-separated list of files to exclude, as set by the
+	// command-line flag.
+	exclude string
+
+	// an array of patterns to exclude, calculated from the
+	// exclude setting above.
+	excluded []string
+
+	// Should we report on what we're testing.
+	verbose bool
+}
+
+// identReader is a hack which allows us to ignore character-conversion
+// issues, depending on the encoded-characterset of the XML input.
+//
+// We use this because we care little for the attributes/values, instead
+// wanting to check for tag-validity.
+func identReader(encoding string, input io.Reader) (io.Reader, error) {
+	return input, nil
+}
+
+// Arguments adds per-command args to the object.
+func (vx *validateXMLCommand) Arguments(f *flag.FlagSet) {
+	f.BoolVar(&vx.verbose, "verbose", false, "Should we be verbose")
+	f.StringVar(&vx.exclude, "exclude", "", "Comma-separated list of patterns to exclude files from the check")
+
+}
+
+// Info returns the name of this subcommand.
+func (vx *validateXMLCommand) Info() (string, string) {
+	return "validate-xml", `Validate all XML files for syntax.
+
+Details:
+
+This command allows you to validate XML files, by default searching
+recursively beneath the current directory for all files which match
+the pattern '*.xml'.
+
+If you prefer you may specify a number of directories or files:
+
+- Any file specified will be checked.
+- Any directory specified will be recursively scanned for matching files.
+  - Files that do not have a '.xml' suffix will be ignored.
+
+Example:
+
+    $ sysbox validate-xml -verbose file1.xml file2.xml ..
+    $ sysbox validate-xml -exclude=foo /dir/1/path /file/1/path ..
+`
+}
+
+// Validate a single file
+func (vx *validateXMLCommand) validateFile(path string) error {
+
+	// Exclude this file? Based on the supplied list though?
+	for _, ex := range vx.excluded {
+		if strings.Contains(path, ex) {
+			if vx.verbose {
+				fmt.Printf("SKIPPED\t%s - matched '%s'\n", path, ex)
+			}
+			return nil
+		}
+	}
+
+	// Read the file-contents
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	// Store the results here.
+	var result interface{}
+
+	// Decode into the results, taking care that we
+	// wire up some magic to avoid caring about the
+	// encoding/character-set issues.
+	r := bytes.NewReader(data)
+	decoder := xml.NewDecoder(r)
+	decoder.CharsetReader = identReader
+	err = decoder.Decode(&result)
+
+	// Show the error if there was one, but otherwise only show
+	// the success if running verbosely.
+	if err != nil {
+		fmt.Printf("ERROR\t%s - %s\n", path, err.Error())
+	} else {
+		if vx.verbose {
+			fmt.Printf("OK\t%s\n", path)
+		}
+	}
+	return err
+}
+
+// Execute is invoked if the user specifies `validate-xml` as the subcommand.
+func (vx *validateXMLCommand) Execute(args []string) int {
+
+	// Did we find at least one file with an error?
+	failed := false
+
+	// Create our array of excluded patterns if something
+	// should be excluded.
+	if vx.exclude != "" {
+		vx.excluded = strings.Split(vx.exclude, ",")
+	}
+
+	// Add a fake argument if nothing is present, because we
+	// want to process the current directory (recursively) by default.
+	if len(args) < 1 {
+		args = append(args, ".")
+	}
+
+	// We can handle file/directory names as arguments.  If a
+	// directory is specified then we process it recursively.
+	//
+	// We'll start by building up a list of all the files to test,
+	// before we begin the process of testing.  We'll make sure
+	// our list is unique to cut down on any unnecessary I/O.
+	todo := make(map[string]bool)
+
+	// For each argument ..
+	for _, arg := range args {
+
+		// Check that it actually exists.
+		info, err := os.Stat(arg)
+		if os.IsNotExist(err) {
+			fmt.Printf("The path does not exist: %s\n", arg)
+			continue
+		}
+
+		// Error?
+		if err != nil {
+			fmt.Printf("Failed to stat(%s): %s\n", arg, err.Error())
+			continue
+		}
+
+		// A directory?
+		if info.Mode().IsDir() {
+
+			// Find suitable entries in the directory
+			files, err := FindFiles(arg, []string{".xml"})
+			if err != nil {
+				fmt.Printf("Error finding files in %s: %s\n", arg, err.Error())
+				continue
+			}
+
+			// Then record each one.
+			for _, ent := range files {
+				todo[ent] = true
+			}
+		} else {
+
+			// OK the entry we were given is just a file,
+			// so we'll save the path away.
+			todo[arg] = true
+		}
+	}
+
+	//
+	// Now we have a list of files to process.
+	//
+	for file := range todo {
+
+		// Run the validation, and note the result
+		err := vx.validateFile(file)
+		if err != nil {
+			failed = true
+		}
+	}
+
+	// Setup a suitable exit-code
+	if failed {
+		return 1
+	}
+
+	return 0
+}

Diff for: main.go

@@ -54,6 +54,7 @@ func main() {
 	subcommands.Register(&treeCommand{})
 	subcommands.Register(&urlsCommand{})
 	subcommands.Register(&validateJSONCommand{})
+	subcommands.Register(&validateXMLCommand{})
 	subcommands.Register(&validateYAMLCommand{})
 	subcommands.Register(&withLockCommand{})