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author | Gabriel A. Giovanini <mail@gabrielgio.me> | 2023-12-09 18:14:51 +0100 |
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committer | Gabriel A. Giovanini <mail@gabrielgio.me> | 2023-12-09 18:17:36 +0100 |
commit | 8049a4e0decd7b233cf2c2339ad0e57a0a029898 (patch) | |
tree | c28c8214a7f2482ad8d98c84ab68176029776fb8 /examples | |
download | pipe-8049a4e0decd7b233cf2c2339ad0e57a0a029898.tar.gz pipe-8049a4e0decd7b233cf2c2339ad0e57a0a029898.tar.bz2 pipe-8049a4e0decd7b233cf2c2339ad0e57a0a029898.zip |
Initial commit
Diffstat (limited to 'examples')
-rw-r--r-- | examples/countlines.go | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/examples/countlines.go b/examples/countlines.go new file mode 100644 index 0000000..000efa5 --- /dev/null +++ b/examples/countlines.go @@ -0,0 +1,135 @@ +package main + +import ( + "bufio" + "errors" + "flag" + "fmt" + "os" + "path/filepath" + "unicode/utf8" + + "git.sr.ht/~gabrielgio/pipe" +) + +var ( + InvalidInput = errors.New("It was given a file instead of a folder.") + ColorGreen = "\033[32m" + ColorRed = "\033[31m" + ColorReset = "\033[0m" +) + +type ( + NonTextError struct { + Filename string + } +) + +func NewNonTextError(filename string) *NonTextError { + return &NonTextError{Filename: filename} +} + +func (b *NonTextError) Error() string { + return fmt.Sprintf("Non text file %s", b.Filename) +} + +func main() { + err := run() + if err != nil { + fmt.Printf("Error on main process: %s", err.Error()) + } +} + +func run() error { + var ( + dir = flag.String("dir", "", "Folder to recursively search for files. Default: \"\"") + quiet = flag.Bool("quiet", false, "If true only outputs the result. Default: false") + nproc = flag.Int("nproc", 4, "Number of goroutines used to count. Default: 4") + ) + + flag.Parse() + + info, err := os.Stat(*dir) + if err != nil { + return err + } + + if !info.IsDir() { + return InvalidInput + } + + cerr := make(chan error) + go func(c <-chan error) { + for e := range c { + if !*quiet { + fmt.Printf("%sERROR%s: %s\n", ColorRed, ColorReset, e.Error()) + } + } + }(cerr) + + c := count(*dir, *nproc, cerr) + fmt.Printf("%sCOUNT%s: %d\n", ColorGreen, ColorReset, c) + + return nil +} + +func count(dir string, nproc int, cerr chan<- error) int { + cfiles := walkFolder(dir) + ccount := pipe.ProcWithError(cfiles, cerr, nproc, countLines) + return pipe.TailReduceWithError(ccount, cerr, sum, 0) +} + +func sum(acc, lines int) (int, error) { + return acc + lines, nil +} + +func countLines(filename string) (int, error) { + + file, err := os.Open(filename) + if err != nil { + return 0, err + } + + defer file.Close() + + fileScanner := bufio.NewScanner(file) + fileScanner.Split(bufio.ScanLines) + + var count int + for fileScanner.Scan() { + if !utf8.ValidString(string(fileScanner.Text())) { + return 0, NewNonTextError(filename) + } + count++ + } + + return count, nil +} + +func walkFolder(folder string) <-chan string { + c := make(chan string) + + go func(folder string, c chan string) { + filepath.Walk(folder, func(path string, info os.FileInfo, err error) error { + file, err := os.Open(path) + if err != nil { + return filepath.SkipDir + } + defer file.Close() + + fileInfo, err := file.Stat() + if err != nil { + return filepath.SkipDir + } + + if !fileInfo.IsDir() { + c <- path + } + return nil + }) + close(c) + + }(folder, c) + + return c +} |