add support for running ccwc against the stdin

golang/.golangci.yml

@@ -0,0 +1,40 @@
+linters:
+  disable-all: true
+  enable:
+    - errcheck
+    - gosimple
+    - govet
+    - ineffassign
+    - staticcheck
+    - typecheck
+    - unused
+    - asciicheck
+    - bodyclose
+    - dogsled
+    - exhaustive
+    - gocognit
+    - goconst
+    - gofmt
+    - goheader
+    - goimports
+    - gosec
+    - misspell
+    - nakedret
+    - nestif
+    - noctx
+    - rowserrcheck
+    - sqlclosecheck
+    - unconvert
+    - unparam
+    - whitespace
+
+issues:
+  exclude:
+    - "composite literal uses unkeyed fields"
+  exclude-rules:
+    - path: _test\.go
+      linters:
+        - gosec
+        - noctx
+        - unparam
+        - bodyclose

golang/README.md

@@ -2,4 +2,17 @@
 
 A reimplementation of [wc](https://en.wikipedia.org/wiki/Wc_(Unix)) as based on [Coding Challenges / Build Your Own wc Tool](https://codingchallenges.fyi/challenges/challenge-wc).
 
-`TODO: DOC TO BE WRITTEN`
+## Instructions
+
+1 - Build a binary by running `make build` which will save the binary in `bin/ccwc`
+
+2 - Running commands against a file: `bin/ccwc -c path/to/file`
+
+3 - Running commands against the standard input: `cat path/to/file | bin/ccwc -c`
+
+## Commands implemented
+
+- `-c` - The number of bytes in each input file is written to the standard output.
+- `-l` - The number of lines in each input file is written to the standard output.
+- `-m` - The number of characters in each input file is written to the standard output.
+-  `w` - The number of words in each input file is written to the standard output.

golang/main.go

@@ -18,21 +18,29 @@ func main() {
 	countCharactersCmd := flag.Bool("m", false, "ccwc -m path/to/file - Returns the number of characters in the file specified")
 	flag.Parse()
 
-	fileName := os.Args[len(os.Args)-1]
-
-	if strings.TrimSpace(fileName) == "" {
-		fmt.Println("A file must be specified. E.g.: ccwc -c path/to/file")
-		os.Exit(1)
+	var err error
+	var fileName string
+	var fileSource *os.File
+
+	if len(os.Args) == 1 || len(os.Args) == 2 && (os.Args[1] == "-c" || os.Args[1] == "-l" || os.Args[1] == "-w" || os.Args[1] == "-m") {
+		fileSource = os.Stdin
+	} else {
+		fileName = os.Args[len(os.Args)-1]
+		fileSource, err = os.Open(fileName)
+		if err != nil {
+			fmt.Printf("error opening the file '%s': %v", fileName, err)
+			return
+		}
 	}
 
-	f, err := os.Open(fileName)
-	if err != nil {
-		fmt.Printf("error opening the file '%s': %v", fileName, err)
-		return
-	}
-	defer func() { _ = f.Close() }()
+	defer func() {
+		closeErr := fileSource.Close()
+		if closeErr != nil {
+			fmt.Printf("error closing file or stdin: %v\n", closeErr)
+		}
+	}()
 
-	result, err := getStatsFromReader(f)
+	result, err := getStatsFromReader(fileSource)
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)