rclone/fs/glob.go
Nick Craig-Wood a91bcaaeb0 Implement rsync like include and exclude - fixes #27
* Implement include/exclude
  * Implement rsync compatible file globbing
  * Implement command line filtering flags
    * --delete-excluded - Delete files on dest excluded from sync
    * --filter - Add a file-filtering rule
    * --filter-from - Read filtering patterns from a file
    * --exclude - Exclude files matching pattern
    * --exclude-from - Read exclude patterns from file
    * --include - Include files matching pattern
    * --include-from - Read include patterns from file
    * --files-from - Read list of source-file nam
    * --min-size - Don't transfer any file smaller than this in k or suffix k|M|G
    * --max-size - Don't transfer any file larger than this in k or suffix k|M|G
  * Document
2015-09-28 19:18:21 +01:00

117 lines
2.3 KiB
Go

// rsync style glob parser
package fs
import (
"bytes"
"fmt"
"regexp"
"strings"
)
// globToRegexp converts an rsync style glob to a regexp
//
// documented in filtering.md
func globToRegexp(glob string) (*regexp.Regexp, error) {
var re bytes.Buffer
if strings.HasPrefix(glob, "/") {
glob = glob[1:]
_, _ = re.WriteRune('^')
} else {
_, _ = re.WriteString("(^|/)")
}
consecutiveStars := 0
insertStars := func() error {
if consecutiveStars > 0 {
switch consecutiveStars {
case 1:
_, _ = re.WriteString(`[^/]*`)
case 2:
_, _ = re.WriteString(`.*`)
default:
return fmt.Errorf("too many stars in %q", glob)
}
}
consecutiveStars = 0
return nil
}
inBraces := false
inBrackets := 0
slashed := false
for _, c := range glob {
if slashed {
_, _ = re.WriteRune(c)
slashed = false
continue
}
if c != '*' {
err := insertStars()
if err != nil {
return nil, err
}
}
if inBrackets > 0 {
_, _ = re.WriteRune(c)
if c == '[' {
inBrackets++
}
if c == ']' {
inBrackets--
}
continue
}
switch c {
case '\\':
_, _ = re.WriteRune(c)
slashed = true
case '*':
consecutiveStars++
case '?':
_, _ = re.WriteString(`[^/]`)
case '[':
_, _ = re.WriteRune(c)
inBrackets++
case ']':
return nil, fmt.Errorf("mismatched ']' in glob %q", glob)
case '{':
if inBraces {
return nil, fmt.Errorf("can't nest '{' '}' in glob %q", glob)
}
inBraces = true
_, _ = re.WriteRune('(')
case '}':
if !inBraces {
return nil, fmt.Errorf("mismatched '{' and '}' in glob %q", glob)
}
_, _ = re.WriteRune(')')
inBraces = false
case ',':
if inBraces {
_, _ = re.WriteRune('|')
} else {
_, _ = re.WriteRune(c)
}
case '.', '+', '(', ')', '|', '^', '$': // regexp meta characters not dealt with above
_, _ = re.WriteRune('\\')
_, _ = re.WriteRune(c)
default:
_, _ = re.WriteRune(c)
}
}
err := insertStars()
if err != nil {
return nil, err
}
if inBrackets > 0 {
return nil, fmt.Errorf("mismatched '[' and ']' in glob %q", glob)
}
if inBraces {
return nil, fmt.Errorf("mismatched '{' and '}' in glob %q", glob)
}
_, _ = re.WriteRune('$')
result, err := regexp.Compile(re.String())
if err != nil {
return nil, fmt.Errorf("Bad glob pattern %q: %v (%q)", glob, err, re.String())
}
return result, nil
}