Initial commit

This moved from here: https://github.com/brejoc/misc/blob/a69909e3dc15e3df140c0a744d833687eca83bcd/SUSE/bscdiff.go

Author: brejoc

.gitignore

@@ -10,3 +10,6 @@
 
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
+
+# Generated binary
+bscdiff

bscdiff.go

@@ -0,0 +1,177 @@
+// bscdiff compares bsc, issue and CVE numbers from a source changelog, to a
+// target changelog. Missing numbers are then printed with their occurrence
+// in the source changelog.
+//
+// Usage: bscdiff <source_file> <target_file>
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+	"sort"
+)
+
+type searchResult struct {
+	line  int
+	match []string
+	text  string
+}
+
+var regexStrings []string
+
+func main() {
+	// These are the regex-strings that will be used later on.
+	regexStrings = []string{
+		`bsc#\d*`,
+		`U#\d*`,
+		`(CVE-(1999|2\d{3})-(0\d{2}[1-9]|[1-9]\d{3,}))`}
+
+	args := os.Args
+
+	if len(args) > 1 && (args[1] == "-h" || args[1] == "--help") {
+		fmt.Println("bscdiff compares bsc, issue and CVE numbers from a source changelog, ")
+		fmt.Println("to a target changelog. Missing numbers are then printed with their ")
+		fmt.Println("occurrence in the source changelog")
+		fmt.Println()
+		fmt.Println(fmt.Sprintf("usage: %s <source_file> <target_file>\n", args[0]))
+		os.Exit(0)
+	}
+
+	if len(args) < 3 {
+		fmt.Fprintf(os.Stderr, "usage: %s <source_file> <target_file>", args[0])
+		os.Exit(1)
+	}
+
+	// Check if files are actually there… and files.
+	for _, file := range os.Args[1:3] {
+		if !fileExists(file) {
+			fmt.Fprintf(os.Stderr, "%s does not exist!", file)
+			os.Exit(1)
+		}
+	}
+
+	searchResults1 := scanFile(args[1])
+	searchResults2 := scanFile(args[2])
+	missingBscs := findMissingBsc(searchResults1, searchResults2)
+	prettyPrintMissingBscs(searchResults1, missingBscs)
+}
+
+// Outputs the missing BSC numbers in a useful format.
+func prettyPrintMissingBscs(searchResults1 []searchResult, missingBscs []string) {
+	sort.Strings(missingBscs)
+	for _, bsc := range missingBscs {
+		for _, searchResult := range searchResults1 {
+			searchPos := sort.SearchStrings(searchResult.match, bsc)
+			if searchPos < len(searchResult.match) && searchResult.match[searchPos] == bsc {
+				fmt.Println(fmt.Sprintf("%d: %s -> %s",
+					searchResult.line,
+					bsc,
+					searchResult.text))
+			}
+		}
+	}
+}
+
+// Returns a list of BSC numbers, that are missing from the second changelog file.
+func findMissingBsc(changelog1 []searchResult, changelog2 []searchResult) []string {
+	bscList1 := getBscs(changelog1)
+	bscList2 := getBscs(changelog2)
+	sort.Strings(bscList1)
+	sort.Strings(bscList2)
+
+	var missingBscs []string
+	for _, bsc := range bscList1 {
+		searchPos := sort.SearchStrings(bscList2, bsc)
+		if searchPos < len(bscList2) && bscList2[searchPos] == bsc {
+			// found it
+		} else {
+			missingBscs = append(missingBscs, bsc)
+		}
+	}
+	return removeDuplicates(missingBscs)
+}
+
+// Extracts the BSC numbers from the search results and returns them as an array.
+func getBscs(res []searchResult) []string {
+	var bsc []string
+	for _, v := range res {
+		for _, value := range v.match {
+			bsc = append(bsc, value)
+		}
+	}
+	return bsc
+}
+
+// Scans the file for bsc, CVE and issue numbers and returns the search results.
+func scanFile(pathToFile string) []searchResult {
+	var regexes []*regexp.Regexp
+	// creating the regexes with the regex-strings from main().
+	for _, regexString := range regexStrings {
+		var re, _ = regexp.Compile(regexString)
+		regexes = append(regexes, re)
+	}
+	lines, err := scanLines(pathToFile)
+	if err != nil {
+		panic(err)
+	}
+	var searchResults []searchResult
+	for i, line := range lines {
+		for _, re := range regexes {
+			results := re.FindAllString(line, -1)
+			if len(results) > 0 {
+				res := searchResult{
+					line:  i + 1,
+					match: results,
+					text:  line}
+				searchResults = append(searchResults, res)
+			}
+		}
+	}
+	return searchResults
+}
+
+// Returns the given file as an array of lines.
+func scanLines(path string) ([]string, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	scanner := bufio.NewScanner(file)
+	scanner.Split(bufio.ScanLines)
+	var lines []string
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+	return lines, nil
+}
+
+// Removes duplicates form an array.
+func removeDuplicates(s []string) []string {
+	m := make(map[string]bool)
+	for _, item := range s {
+		if _, ok := m[item]; ok {
+			// duplicate item
+		} else {
+			m[item] = true
+		}
+	}
+	var result []string
+	for item := range m {
+		result = append(result, item)
+	}
+	return result
+}
+
+// fileExists checks if a file exists and is not a directory before we
+// try using it to prevent further errors.
+func fileExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return !info.IsDir()
+}