Merge pull request #18 from onozaty/develop/v1.12.0

Develop v1.12.0

README.md

@@ -14,6 +14,7 @@
 * [count](#count) Count the number of records.
 * [exclude](#exclude) Exclude rows by included in another CSV file.
 * [filter](#filter) Filter rows by condition.
+* [head](#head) Show head few rows.
 * [header](#header) Show header.
 * [include](#include) Filter rows by included in another CSV file.
 * [join](#join) Join CSV files.
@@ -454,6 +455,76 @@ Please refer to the following for the syntax of regular expressions.
 
 * https://pkg.go.dev/regexp/syntax
 
+## head
+
+Show the first few rows.  
+It will be shown in table format.
+
+### Usage
+
+```
+csvt head -i INPUT  [-n NUMBER]
+```
+
+```
+Usage:
+  csvt head [flags]
+
+Flags:
+  -i, --input string   Input CSV file path.
+  -n, --number int     The number of records to show. If not specified, it will be the first 10 rows. (default 10)
+  -h, --help           help for head
+```
+
+### Example
+
+The contents of `input.csv`.
+
+```
+UserID,Name,Age
+1,"Taro, Yamada",10
+2,Hanako,21
+3,Smith,30
+4,Jun,22
+5,Kevin,10
+6,Bob,
+7,Jackson,51
+8,Harry,22
+9,Olivia,32
+10,Aiko,35
+11,Kaede,9
+12,Sakura,12
+13,Momoka,16
+```
+
+```
+$ csvt head -i input.csv
++--------+--------------+-----+
+| UserID | Name         | Age |
++--------+--------------+-----+
+| 1      | Taro, Yamada | 10  |
+| 2      | Hanako       | 21  |
+| 3      | Smith        | 30  |
+| 4      | Jun          | 22  |
+| 5      | Kevin        | 10  |
+| 6      | Bob          |     |
+| 7      | Jackson      | 51  |
+| 8      | Harry        | 22  |
+| 9      | Olivia       | 32  |
+| 10     | Aiko         | 35  |
++--------+--------------+-----+
+```
+
+```
+$ csvt head -i input.csv -n 2
++--------+--------------+-----+
+| UserID | Name         | Age |
++--------+--------------+-----+
+| 1      | Taro, Yamada | 10  |
+| 2      | Hanako       | 21  |
++--------+--------------+-----+
+```
+
 ## header
 
 Show the header of CSV file.

cmd/head.go

@@ -0,0 +1,89 @@
+package cmd
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/olekukonko/tablewriter"
+	"github.com/onozaty/csvt/csv"
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+)
+
+func newHeadCmd() *cobra.Command {
+
+	headCmd := &cobra.Command{
+		Use:   "head",
+		Short: "Show head few rows",
+		RunE: func(cmd *cobra.Command, args []string) error {
+
+			format, err := getFlagBaseCsvFormat(cmd.Flags())
+			if err != nil {
+				return err
+			}
+
+			inputPath, _ := cmd.Flags().GetString("input")
+			number, _ := cmd.Flags().GetInt("number")
+
+			// 表示件数は1以上
+			if number <= 0 {
+				return fmt.Errorf("number must be greater than or equal to 1")
+			}
+
+			// 引数の解析に成功した時点で、エラーが起きてもUsageは表示しない
+			cmd.SilenceUsage = true
+
+			return runHead(
+				format,
+				inputPath,
+				number,
+				cmd.OutOrStdout())
+		},
+	}
+
+	headCmd.Flags().StringP("input", "i", "", "Input CSV file path.")
+	headCmd.MarkFlagRequired("input")
+	headCmd.Flags().IntP("number", "n", 10, "The number of records to show. If not specified, it will be the first 10 rows.")
+
+	return headCmd
+}
+
+func runHead(format csv.Format, inputPath string, number int, writer io.Writer) error {
+
+	reader, close, err := setupInput(inputPath, format)
+	if err != nil {
+		return err
+	}
+	defer close()
+
+	return head(reader, number, writer)
+}
+
+func head(reader csv.CsvReader, number int, writer io.Writer) error {
+
+	columnNames, err := reader.Read()
+	if err != nil {
+		return errors.Wrap(err, "failed to read the input CSV file")
+	}
+
+	table := tablewriter.NewWriter(writer)
+	table.SetAutoFormatHeaders(false)
+	table.SetHeaderAlignment(tablewriter.ALIGN_LEFT)
+	table.SetAlignment(tablewriter.ALIGN_LEFT)
+	table.SetHeader(columnNames)
+
+	for i := 0; i < number; i++ {
+		row, err := reader.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return errors.Wrap(err, "failed to read the input CSV file")
+		}
+
+		table.Append(row)
+	}
+
+	table.Render()
+	return nil
+}

cmd/head_test.go

@@ -0,0 +1,212 @@
+package cmd
+
+import (
+	"bytes"
+	"os"
+	"testing"
+)
+
+func TestHeadCmd(t *testing.T) {
+
+	s := `ID,Name,Company ID
+1,Yamada,1
+2,Ichikawa,
+3,"Hanako, Sato",3
+4,Otani,3
+5,,2
+6,Suzuki,1
+7,Jane,2
+8,Michel,3
+9,1,3
+10,Ken,3
+11,Suzuki,2
+12,Z,
+`
+	f := createTempFile(t, s)
+	defer os.Remove(f)
+
+	rootCmd := newRootCmd()
+	rootCmd.SetArgs([]string{
+		"head",
+		"-i", f,
+	})
+
+	buf := new(bytes.Buffer)
+	rootCmd.SetOutput(buf)
+
+	err := rootCmd.Execute()
+	if err != nil {
+		t.Fatal("failed test\n", err)
+	}
+
+	result := buf.String()
+
+	except := `+----+--------------+------------+
+| ID | Name         | Company ID |
++----+--------------+------------+
+| 1  | Yamada       | 1          |
+| 2  | Ichikawa     |            |
+| 3  | Hanako, Sato | 3          |
+| 4  | Otani        | 3          |
+| 5  |              | 2          |
+| 6  | Suzuki       | 1          |
+| 7  | Jane         | 2          |
+| 8  | Michel       | 3          |
+| 9  | 1            | 3          |
+| 10 | Ken          | 3          |
++----+--------------+------------+
+`
+	if result != except {
+		t.Fatal("failed test\n", result)
+	}
+}
+
+func TestHeadCmd_number(t *testing.T) {
+
+	s := `ID,Name,Company ID
+1,Yamada,1
+2,Ichikawa,
+3,"Hanako, Sato",3
+4,Otani,3
+5,,2
+`
+	f := createTempFile(t, s)
+	defer os.Remove(f)
+
+	rootCmd := newRootCmd()
+	rootCmd.SetArgs([]string{
+		"head",
+		"-i", f,
+		"-n", "3",
+	})
+
+	buf := new(bytes.Buffer)
+	rootCmd.SetOutput(buf)
+
+	err := rootCmd.Execute()
+	if err != nil {
+		t.Fatal("failed test\n", err)
+	}
+
+	result := buf.String()
+
+	except := `+----+--------------+------------+
+| ID | Name         | Company ID |
++----+--------------+------------+
+| 1  | Yamada       | 1          |
+| 2  | Ichikawa     |            |
+| 3  | Hanako, Sato | 3          |
++----+--------------+------------+
+`
+	if result != except {
+		t.Fatal("failed test\n", result)
+	}
+}
+
+func TestHeadCmd_less(t *testing.T) {
+
+	s := `ID,Name,Company ID
+1,Yamada,1
+2,Ichikawa,
+`
+	f := createTempFile(t, s)
+	defer os.Remove(f)
+
+	rootCmd := newRootCmd()
+	rootCmd.SetArgs([]string{
+		"head",
+		"-i", f,
+	})
+
+	buf := new(bytes.Buffer)
+	rootCmd.SetOutput(buf)
+
+	err := rootCmd.Execute()
+	if err != nil {
+		t.Fatal("failed test\n", err)
+	}
+
+	result := buf.String()
+
+	except := `+----+----------+------------+
+| ID | Name     | Company ID |
++----+----------+------------+
+| 1  | Yamada   | 1          |
+| 2  | Ichikawa |            |
++----+----------+------------+
+`
+	if result != except {
+		t.Fatal("failed test\n", result)
+	}
+}
+
+func TestHeadCmd_format(t *testing.T) {
+
+	s := "col1,col2;1,a;2,b;"
+
+	f := createTempFile(t, s)
+	defer os.Remove(f)
+
+	rootCmd := newRootCmd()
+	rootCmd.SetArgs([]string{
+		"head",
+		"-i", f,
+		"--sep", ";",
+	})
+
+	buf := new(bytes.Buffer)
+	rootCmd.SetOutput(buf)
+
+	err := rootCmd.Execute()
+	if err != nil {
+		t.Fatal("failed test\n", err)
+	}
+
+	result := buf.String()
+
+	except := `+------+------+
+| col1 | col2 |
++------+------+
+| 1    | a    |
+| 2    | b    |
++------+------+
+`
+	if result != except {
+		t.Fatal("failed test\n", result)
+	}
+}
+
+func TestHeadCmd_invalidNumber(t *testing.T) {
+
+	f := createTempFile(t, "")
+	defer os.Remove(f)
+
+	rootCmd := newRootCmd()
+	rootCmd.SetArgs([]string{
+		"head",
+		"-i", f,
+		"-n", "0",
+	})
+
+	err := rootCmd.Execute()
+	if err == nil || err.Error() != "number must be greater than or equal to 1" {
+		t.Fatal("failed test\n", err)
+	}
+}
+
+func TestHeadCmd_empty(t *testing.T) {
+
+	f := createTempFile(t, "")
+	defer os.Remove(f)
+
+	rootCmd := newRootCmd()
+	rootCmd.SetArgs([]string{
+		"head",
+		"-i", f,
+	})
+
+	err := rootCmd.Execute()
+	if err == nil || err.Error() != "failed to read the input CSV file: EOF" {
+		t.Fatal("failed test\n", err)
+	}
+}

cmd/root.go

@@ -43,6 +43,7 @@ func newRootCmd() *cobra.Command {
 	rootCmd.AddCommand(newAddCmd())
 	rootCmd.AddCommand(newSortCmd())
 	rootCmd.AddCommand(newSplitCmd())
+	rootCmd.AddCommand(newHeadCmd())
 
 	for _, c := range rootCmd.Commands() {
 		// フラグ以外は受け付けないように