gg/main.go

311 lines
6.5 KiB
Go

/*
gg is a recursive grep written in Go, with some shortcuts for everyday use.
*/
package main
import (
"bytes"
"errors"
"fmt"
"os"
"path/filepath"
"regexp"
"strings"
"unicode"
"unicode/utf8"
"github.com/spf13/cobra"
"golang.org/x/sys/unix"
)
// TODO:
// - bold of escaped output doesn't work
// - binary file detection
// - long-line / minified-file detection
// - ignore files by extension (or glob?)
func main() {
if err := rootCmd.Execute(); err != nil {
os.Exit(1)
}
}
var rootCmd = &cobra.Command{
Use: "gg pattern [path1 [path2 …]]",
Short: "gg is a recursive grep",
Long: `gg is a recursive grep. Given a regexp (or fixed pattern) it will search for
the pattern recursively in the current working directory. It will print a
coloured header per file along with the matching line and pattern.
It is possible to scan specific files or directories, rather than the default
current working directory. To do this, simply specify the path(s) as arguments
following the pattern.
It is possible to scan for multiple patterns using the -e (or -Q) argument,
which can be repeated multiple times. -e specifies a regular expression and
-Q a fixed pattern. When using either flag, any non-flag arguments are treated
as paths to scan.
Search defaults to case-sensitive but the -i flag may be passed to make regular
expression searches case-insensitive. Alternatively, the "(?i)" construct may be
added to a regular expression to make that specific expression case insensitive.
Fixed pattern matches are always case-sensitive.`,
RunE: run,
}
var (
searchRegexp []string
regexps []*regexp.Regexp
searchFixed []string
searchBytes [][]byte
searchPath []string
ignoreList []string
ignoreMap map[string]struct{}
ignoreCase bool
noColour bool
display *Display
matchedAny bool
)
func init() {
rootCmd.Flags().StringSliceVarP(&searchRegexp, "grep", "e", nil, "pattern to match (regular expression)")
rootCmd.Flags().StringSliceVarP(&searchFixed, "fixed", "Q", nil, "pattern to match (fixed string)")
rootCmd.Flags().StringSliceVarP(&ignoreList, "exclude", "x", []string{".git"}, "files/directories to exclude")
rootCmd.Flags().BoolVarP(&ignoreCase, "ignore-case", "i", false, "make all searches case insensitive")
rootCmd.Flags().BoolVarP(&noColour, "no-colour", "C", false, "disable colour output")
}
func run(c *cobra.Command, args []string) error {
display = NewDisplay(noColour)
if len(searchRegexp) == 0 && len(searchFixed) == 0 {
if len(args) == 0 {
return errors.New("no pattern specified")
}
searchRegexp = append(searchRegexp, args[0])
args = args[1:]
}
searchPath = args
if len(searchPath) == 0 {
searchPath = append(searchPath, ".")
}
ignoreMap = make(map[string]struct{}, len(ignoreList))
for _, i := range ignoreList {
ignoreMap[i] = struct{}{}
}
for _, r := range searchRegexp {
if ignoreCase {
r = "(?i)" + r
}
re, err := regexp.Compile(r)
if err != nil {
return err
}
regexps = append(regexps, re)
}
for _, s := range searchFixed {
searchBytes = append(searchBytes, []byte(s))
}
var errs []error
for _, path := range searchPath {
if err := search(path); err != nil {
errs = append(errs, err)
}
}
return errors.Join(errs...)
}
func recurse(path string) error {
d, err := os.ReadDir(path)
if err != nil {
return err
}
var errs []error
for _, de := range d {
name := de.Name()
fullPath := filepath.Join(path, name)
if _, ignored := ignoreMap[name]; ignored {
continue
}
if err := search(fullPath); err != nil {
errs = append(errs, err)
}
}
return errors.Join(errs...)
}
func search(path string) error {
st, err := os.Stat(path)
if err != nil {
return err
}
switch {
case st.IsDir():
return recurse(path)
case !st.Mode().IsRegular(),
st.Size() == 0:
return nil
}
f, err := os.Open(path)
if err != nil {
return err
}
defer f.Close()
fullData, err := unix.Mmap(int(f.Fd()), 0, int(st.Size()), unix.PROT_READ, unix.MAP_PRIVATE)
if err != nil {
return err
}
defer unix.Munmap(fullData)
var printedHeader bool
var (
data = fullData
lineNum int
b, b2 strings.Builder
)
for len(data) > 0 {
eol := bytes.IndexByte(data, '\n')
lineNum++
var line []byte
if eol == -1 {
line = data
data = nil
} else {
line = data[:eol]
data = data[eol+1:]
}
if len(line) == 0 {
continue
}
loc := matches(line)
if loc == nil {
continue
}
if !printedHeader {
printedHeader = true
if !matchedAny {
matchedAny = true
} else {
fmt.Println("")
}
fmt.Println(display.Filename(path))
}
b.Reset()
fmt.Fprintf(&b, "%4d: ", display.LineNumber(lineNum))
if loc[0] < 128 {
escape(&b, line[0:loc[0]])
} else {
start := loc[0] - 128
for i := 0; i < 5; i++ {
if utf8.RuneStart(line[start]) {
break
}
start++
}
b.WriteString(display.TruncatedBytes(start).String())
b.WriteString(display.TruncatedMarker().String())
escape(&b, line[start:loc[0]])
}
if loc[1]-loc[0] < 128 {
b2.Reset()
escape(&b2, line[loc[0]:loc[1]])
b.WriteString(display.Match(b2.String()).String())
if loc[1]+128 > len(line) {
escape(&b, line[loc[1]:])
} else {
end := loc[1] + 128
for i := 0; i < 5; i++ {
if utf8.RuneStart(line[end]) {
break
}
end--
}
escape(&b, line[loc[1]:end])
b.WriteString(display.TruncatedBytes(len(line) - end).String())
b.WriteString(display.TruncatedMarker().String())
}
} else {
end := loc[1]
for i := 0; i < 5; i++ {
if utf8.RuneStart(line[end]) {
break
}
end--
}
b2.Reset()
escape(&b2, line[loc[0]:end])
b.WriteString(display.Match(b2.String()).String())
b.WriteString(display.TruncatedMarker().String())
b.WriteString(display.TruncatedBytes(len(line) - end).String())
}
b.WriteRune('\n')
fmt.Print(b.String())
}
return nil
}
func matches(data []byte) (loc []int) {
for _, re := range regexps {
loc := re.FindIndex(data)
if loc != nil {
return loc
}
}
for _, s := range searchBytes {
pos := bytes.Index(data, s)
if pos != -1 {
return []int{pos, pos + len(s)}
}
}
return nil
}
func escape(b *strings.Builder, s []byte) {
for len(s) > 0 {
r, size := utf8.DecodeRune(s)
s = s[size:]
switch {
case r == utf8.RuneError && size == 1:
b.WriteString(display.BadUTF8Char().String())
case r == '\r':
b.WriteString(display.CarriageReturn().String())
case r == '\t',
unicode.IsPrint(r):
b.WriteRune(r)
default:
b.WriteString(display.UnprintableChar().String())
}
}
}