1 files changed, 314 insertions, 0 deletions
diff --git a/vendor/github.com/openshift/imagebuilder/shell_parser.go b/vendor/github.com/openshift/imagebuilder/shell_parser.go
new file mode 100644
index 000000000..65f1db6dc
--- /dev/null
+++ b/vendor/github.com/openshift/imagebuilder/shell_parser.go
@@ -0,0 +1,314 @@
+package imagebuilder
+
+// This will take a single word and an array of env variables and
+// process all quotes (" and ') as well as $xxx and ${xxx} env variable
+// tokens.  Tries to mimic bash shell process.
+// It doesn't support all flavors of ${xx:...} formats but new ones can
+// be added by adding code to the "special ${} format processing" section
+
+import (
+	"fmt"
+	"strings"
+	"text/scanner"
+	"unicode"
+)
+
+type shellWord struct {
+	word    string
+	scanner scanner.Scanner
+	envs    []string
+	pos     int
+}
+
+// ProcessWord will use the 'env' list of environment variables,
+// and replace any env var references in 'word'.
+func ProcessWord(word string, env []string) (string, error) {
+	sw := &shellWord{
+		word: word,
+		envs: env,
+		pos:  0,
+	}
+	sw.scanner.Init(strings.NewReader(word))
+	word, _, err := sw.process()
+	return word, err
+}
+
+// ProcessWords will use the 'env' list of environment variables,
+// and replace any env var references in 'word' then it will also
+// return a slice of strings which represents the 'word'
+// split up based on spaces - taking into account quotes.  Note that
+// this splitting is done **after** the env var substitutions are done.
+// Note, each one is trimmed to remove leading and trailing spaces (unless
+// they are quoted", but ProcessWord retains spaces between words.
+func ProcessWords(word string, env []string) ([]string, error) {
+	sw := &shellWord{
+		word: word,
+		envs: env,
+		pos:  0,
+	}
+	sw.scanner.Init(strings.NewReader(word))
+	_, words, err := sw.process()
+	return words, err
+}
+
+func (sw *shellWord) process() (string, []string, error) {
+	return sw.processStopOn(scanner.EOF)
+}
+
+type wordsStruct struct {
+	word   string
+	words  []string
+	inWord bool
+}
+
+func (w *wordsStruct) addChar(ch rune) {
+	if unicode.IsSpace(ch) && w.inWord {
+		if len(w.word) != 0 {
+			w.words = append(w.words, w.word)
+			w.word = ""
+			w.inWord = false
+		}
+	} else if !unicode.IsSpace(ch) {
+		w.addRawChar(ch)
+	}
+}
+
+func (w *wordsStruct) addRawChar(ch rune) {
+	w.word += string(ch)
+	w.inWord = true
+}
+
+func (w *wordsStruct) addString(str string) {
+	var scan scanner.Scanner
+	scan.Init(strings.NewReader(str))
+	for scan.Peek() != scanner.EOF {
+		w.addChar(scan.Next())
+	}
+}
+
+func (w *wordsStruct) addRawString(str string) {
+	w.word += str
+	w.inWord = true
+}
+
+func (w *wordsStruct) getWords() []string {
+	if len(w.word) > 0 {
+		w.words = append(w.words, w.word)
+
+		// Just in case we're called again by mistake
+		w.word = ""
+		w.inWord = false
+	}
+	return w.words
+}
+
+// Process the word, starting at 'pos', and stop when we get to the
+// end of the word or the 'stopChar' character
+func (sw *shellWord) processStopOn(stopChar rune) (string, []string, error) {
+	var result string
+	var words wordsStruct
+
+	var charFuncMapping = map[rune]func() (string, error){
+		'\'': sw.processSingleQuote,
+		'"':  sw.processDoubleQuote,
+		'$':  sw.processDollar,
+	}
+
+	for sw.scanner.Peek() != scanner.EOF {
+		ch := sw.scanner.Peek()
+
+		if stopChar != scanner.EOF && ch == stopChar {
+			sw.scanner.Next()
+			break
+		}
+		if fn, ok := charFuncMapping[ch]; ok {
+			// Call special processing func for certain chars
+			tmp, err := fn()
+			if err != nil {
+				return "", []string{}, err
+			}
+			result += tmp
+
+			if ch == rune('$') {
+				words.addString(tmp)
+			} else {
+				words.addRawString(tmp)
+			}
+		} else {
+			// Not special, just add it to the result
+			ch = sw.scanner.Next()
+
+			if ch == '\\' {
+				// '\' escapes, except end of line
+
+				ch = sw.scanner.Next()
+
+				if ch == scanner.EOF {
+					break
+				}
+
+				words.addRawChar(ch)
+			} else {
+				words.addChar(ch)
+			}
+
+			result += string(ch)
+		}
+	}
+
+	return result, words.getWords(), nil
+}
+
+func (sw *shellWord) processSingleQuote() (string, error) {
+	// All chars between single quotes are taken as-is
+	// Note, you can't escape '
+	var result string
+
+	sw.scanner.Next()
+
+	for {
+		ch := sw.scanner.Next()
+		if ch == '\'' || ch == scanner.EOF {
+			break
+		}
+		result += string(ch)
+	}
+
+	return result, nil
+}
+
+func (sw *shellWord) processDoubleQuote() (string, error) {
+	// All chars up to the next " are taken as-is, even ', except any $ chars
+	// But you can escape " with a \
+	var result string
+
+	sw.scanner.Next()
+
+	for sw.scanner.Peek() != scanner.EOF {
+		ch := sw.scanner.Peek()
+		if ch == '"' {
+			sw.scanner.Next()
+			break
+		}
+		if ch == '$' {
+			tmp, err := sw.processDollar()
+			if err != nil {
+				return "", err
+			}
+			result += tmp
+		} else {
+			ch = sw.scanner.Next()
+			if ch == '\\' {
+				chNext := sw.scanner.Peek()
+
+				if chNext == scanner.EOF {
+					// Ignore \ at end of word
+					continue
+				}
+
+				if chNext == '"' || chNext == '$' {
+					// \" and \$ can be escaped, all other \'s are left as-is
+					ch = sw.scanner.Next()
+				}
+			}
+			result += string(ch)
+		}
+	}
+
+	return result, nil
+}
+
+func (sw *shellWord) processDollar() (string, error) {
+	sw.scanner.Next()
+	ch := sw.scanner.Peek()
+	if ch == '{' {
+		sw.scanner.Next()
+		name := sw.processName()
+		ch = sw.scanner.Peek()
+		if ch == '}' {
+			// Normal ${xx} case
+			sw.scanner.Next()
+			return sw.getEnv(name), nil
+		}
+		if ch == ':' {
+			// Special ${xx:...} format processing
+			// Yes it allows for recursive $'s in the ... spot
+
+			sw.scanner.Next() // skip over :
+			modifier := sw.scanner.Next()
+
+			word, _, err := sw.processStopOn('}')
+			if err != nil {
+				return "", err
+			}
+
+			// Grab the current value of the variable in question so we
+			// can use it to determine what to do based on the modifier
+			newValue := sw.getEnv(name)
+
+			switch modifier {
+			case '+':
+				if newValue != "" {
+					newValue = word
+				}
+				return newValue, nil
+
+			case '-':
+				if newValue == "" {
+					newValue = word
+				}
+				return newValue, nil
+
+			default:
+				return "", fmt.Errorf("Unsupported modifier (%c) in substitution: %s", modifier, sw.word)
+			}
+		}
+		return "", fmt.Errorf("Missing ':' in substitution: %s", sw.word)
+	}
+	// $xxx case
+	name := sw.processName()
+	if name == "" {
+		return "$", nil
+	}
+	return sw.getEnv(name), nil
+}
+
+func (sw *shellWord) processName() string {
+	// Read in a name (alphanumeric or _)
+	// If it starts with a numeric then just return $#
+	var name string
+
+	for sw.scanner.Peek() != scanner.EOF {
+		ch := sw.scanner.Peek()
+		if len(name) == 0 && unicode.IsDigit(ch) {
+			ch = sw.scanner.Next()
+			return string(ch)
+		}
+		if !unicode.IsLetter(ch) && !unicode.IsDigit(ch) && ch != '_' {
+			break
+		}
+		ch = sw.scanner.Next()
+		name += string(ch)
+	}
+
+	return name
+}
+
+func (sw *shellWord) getEnv(name string) string {
+	for _, env := range sw.envs {
+		i := strings.Index(env, "=")
+		if i < 0 {
+			if name == env {
+				// Should probably never get here, but just in case treat
+				// it like "var" and "var=" are the same
+				return ""
+			}
+			continue
+		}
+		if name != env[:i] {
+			continue
+		}
+		return env[i+1:]
+	}
+	return ""
+}