1 // Copyright 2009 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // Simple file i/o and string manipulation, to avoid
6 // depending on strconv and bufio and strings.
23 func (f *file) close() { f.file.Close() }
25 func (f *file) getLineFromData() (s string, ok bool) {
28 for i = 0; i < len(data); i++ {
35 copy(data[0:], data[i:])
40 if f.atEOF && len(f.data) > 0 {
41 // EOF, return all we have
49 func (f *file) readLine() (s string, ok bool) {
50 if s, ok = f.getLineFromData(); ok {
53 if len(f.data) < cap(f.data) {
55 n, err := io.ReadFull(f.file, f.data[ln:cap(f.data)])
57 f.data = f.data[0 : ln+n]
59 if err == io.EOF || err == io.ErrUnexpectedEOF {
63 s, ok = f.getLineFromData()
67 func open(name string) (*file, error) {
68 fd, err := os.Open(name)
72 return &file{fd, make([]byte, 0, 64*1024), false}, nil
75 func stat(name string) (mtime time.Time, size int64, err error) {
76 st, err := os.Stat(name)
78 return time.Time{}, 0, err
80 return st.ModTime(), st.Size(), nil
83 // Count occurrences in s of any bytes in t.
84 func countAnyByte(s string, t string) int {
86 for i := 0; i < len(s); i++ {
87 if bytealg.IndexByteString(t, s[i]) >= 0 {
94 // Split s at any bytes in t.
95 func splitAtBytes(s string, t string) []string {
96 a := make([]string, 1+countAnyByte(s, t))
99 for i := 0; i < len(s); i++ {
100 if bytealg.IndexByteString(t, s[i]) >= 0 {
115 func getFields(s string) []string { return splitAtBytes(s, " \r\t\n") }
117 // Bigger than we need, not too big to worry about overflow
120 // Decimal to integer.
121 // Returns number, characters consumed, success.
122 func dtoi(s string) (n int, i int, ok bool) {
124 for i = 0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
125 n = n*10 + int(s[i]-'0')
136 // Hexadecimal to integer.
137 // Returns number, characters consumed, success.
138 func xtoi(s string) (n int, i int, ok bool) {
140 for i = 0; i < len(s); i++ {
141 if '0' <= s[i] && s[i] <= '9' {
144 } else if 'a' <= s[i] && s[i] <= 'f' {
146 n += int(s[i]-'a') + 10
147 } else if 'A' <= s[i] && s[i] <= 'F' {
149 n += int(s[i]-'A') + 10
163 // xtoi2 converts the next two hex digits of s into a byte.
164 // If s is longer than 2 bytes then the third byte must be e.
165 // If the first two bytes of s are not hex digits or the third byte
166 // does not match e, false is returned.
167 func xtoi2(s string, e byte) (byte, bool) {
168 if len(s) > 2 && s[2] != e {
171 n, ei, ok := xtoi(s[:2])
172 return byte(n), ok && ei == 2
175 // Convert integer to decimal string.
176 func itoa(val int) string {
178 return "-" + uitoa(uint(-val))
180 return uitoa(uint(val))
183 // Convert unsigned integer to decimal string.
184 func uitoa(val uint) string {
185 if val == 0 { // avoid string allocation
188 var buf [20]byte // big enough for 64bit value base 10
192 buf[i] = byte('0' + val - q*10)
197 buf[i] = byte('0' + val)
198 return string(buf[i:])
201 // Convert i to a hexadecimal string. Leading zeros are not printed.
202 func appendHex(dst []byte, i uint32) []byte {
204 return append(dst, '0')
206 for j := 7; j >= 0; j-- {
209 dst = append(dst, hexDigit[v&0xf])
215 // Number of occurrences of b in s.
216 func count(s string, b byte) int {
218 for i := 0; i < len(s); i++ {
226 // Index of rightmost occurrence of b in s.
227 func last(s string, b byte) int {
229 for i--; i >= 0; i-- {
237 // lowerASCIIBytes makes x ASCII lowercase in-place.
238 func lowerASCIIBytes(x []byte) {
239 for i, b := range x {
240 if 'A' <= b && b <= 'Z' {
246 // lowerASCII returns the ASCII lowercase version of b.
247 func lowerASCII(b byte) byte {
248 if 'A' <= b && b <= 'Z' {
249 return b + ('a' - 'A')
254 // trimSpace returns x without any leading or trailing ASCII whitespace.
255 func trimSpace(x []byte) []byte {
256 for len(x) > 0 && isSpace(x[0]) {
259 for len(x) > 0 && isSpace(x[len(x)-1]) {
265 // isSpace reports whether b is an ASCII space character.
266 func isSpace(b byte) bool {
267 return b == ' ' || b == '\t' || b == '\n' || b == '\r'
270 // removeComment returns line, removing any '#' byte and any following
272 func removeComment(line []byte) []byte {
273 if i := bytealg.IndexByte(line, '#'); i != -1 {
279 // foreachLine runs fn on each line of x.
280 // Each line (except for possibly the last) ends in '\n'.
281 // It returns the first non-nil error returned by fn.
282 func foreachLine(x []byte, fn func(line []byte) error) error {
284 nl := bytealg.IndexByte(x, '\n')
290 if err := fn(line); err != nil {
297 // foreachField runs fn on each non-empty run of non-space bytes in x.
298 // It returns the first non-nil error returned by fn.
299 func foreachField(x []byte, fn func(field []byte) error) error {
302 sp := bytealg.IndexByte(x, ' ')
306 if field := trimSpace(x[:sp]); len(field) > 0 {
307 if err := fn(field); err != nil {
311 x = trimSpace(x[sp+1:])
316 // stringsHasSuffix is strings.HasSuffix. It reports whether s ends in
318 func stringsHasSuffix(s, suffix string) bool {
319 return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
322 // stringsHasSuffixFold reports whether s ends in suffix,
323 // ASCII-case-insensitively.
324 func stringsHasSuffixFold(s, suffix string) bool {
325 return len(s) >= len(suffix) && stringsEqualFold(s[len(s)-len(suffix):], suffix)
328 // stringsHasPrefix is strings.HasPrefix. It reports whether s begins with prefix.
329 func stringsHasPrefix(s, prefix string) bool {
330 return len(s) >= len(prefix) && s[:len(prefix)] == prefix
333 // stringsEqualFold is strings.EqualFold, ASCII only. It reports whether s and t
334 // are equal, ASCII-case-insensitively.
335 func stringsEqualFold(s, t string) bool {
336 if len(s) != len(t) {
339 for i := 0; i < len(s); i++ {
340 if lowerASCII(s[i]) != lowerASCII(t[i]) {
347 func readFull(r io.Reader) (all []byte, err error) {
348 buf := make([]byte, 1024)
350 n, err := r.Read(buf)
351 all = append(all, buf[:n]...)
361 // goDebugString returns the value of the named GODEBUG key.
362 // GODEBUG is of the form "key=val,key2=val2"
363 func goDebugString(key string) string {
364 s := os.Getenv("GODEBUG")
365 for i := 0; i < len(s)-len(key)-1; i++ {
366 if i > 0 && s[i-1] != ',' {
369 afterKey := s[i+len(key):]
370 if afterKey[0] != '=' || s[i:i+len(key)] != key {
374 for i, b := range val {