Counting lines and words using Go

For those who need to count words and lines in text files, an easy approach for this matter is to use bufio.ScanWords and bufio.ScanLine in order to quickly solve the problem.

To count words:

input := "Spicy jalapeno pastrami ut ham turducken.\n Lorem sed ullamco, leberkas sint short loin strip steak ut shoulder shankle porchetta venison prosciutto turducken swine.\n Deserunt kevin frankfurter tongue aliqua incididunt tri-tip shank nostrud.\n"
scanner := bufio.NewScanner(strings.NewReader(input))

// Set the split function for the scanning operation.
scanner.Split(bufio.ScanWords)

// Count the words.
count := 0
for scanner.Scan() {
    count++
}

if err := scanner.Err(); err != nil {
    fmt.Fprintln(os.Stderr, "reading input:", err)
}

fmt.Printf("%d\n", count)

ScanWords is a split function for a Scanner that returns each space-separated (checks unicode.IsSpace) word of text, with trimmed whitespace.

To count lines:

input := "Spicy jalapeno pastrami ut ham turducken.\n Lorem sed ullamco, leberkas sint short loin strip steak ut shoulder shankle porchetta venison prosciutto turducken swine.\n Deserunt kevin frankfurter tongue aliqua incididunt tri-tip shank nostrud.\n"
scanner := bufio.NewScanner(strings.NewReader(input))

// Set the split function for the scanning operation.
scanner.Split(bufio. ScanLines)

// Count the lines.
count := 0
for scanner.Scan() {
    count++
}

if err := scanner.Err(); err != nil {
    fmt.Fprintln(os.Stderr, "reading input:", err)
}

fmt.Printf("%d\n", count)

ScanLines is a split function for a Scanner that returns each line of text (separated by “\r?\n”). It returns also empty lines and the last line is returned even if it has no newline at the end.