refactored output printer, now using tablewriter

cmd/root.go

@@ -33,6 +33,13 @@ var rootCmd = &cobra.Command{
 			return nil
 		}
 
+		lib.PrepareColumns()
+
+		err := lib.PrepareModeFlags()
+		if err != nil {
+			return err
+		}
+
 		return lib.ProcessFiles(args)
 	},
 }
@@ -46,9 +53,17 @@ func Execute() {
 
 func init() {
 	rootCmd.PersistentFlags().BoolVarP(&lib.Debug, "debug", "d", false, "Enable debugging")
-	rootCmd.PersistentFlags().BoolVarP(&lib.XtendedOut, "extended", "x", false, "Enable extended output")
 	rootCmd.PersistentFlags().BoolVarP(&lib.NoNumbering, "no-numbering", "n", false, "Disable header numbering")
 	rootCmd.PersistentFlags().BoolVarP(&lib.ShowVersion, "version", "v", false, "Print program version")
 	rootCmd.PersistentFlags().StringVarP(&lib.Separator, "separator", "s", "", "Custom field separator")
 	rootCmd.PersistentFlags().StringVarP(&lib.Columns, "columns", "c", "", "Only show the speficied columns (separated by ,)")
+
+	// output flags, only 1 allowed
+	rootCmd.PersistentFlags().BoolVarP(&lib.OutflagExtended, "extended", "X", false, "Enable extended output")
+	rootCmd.PersistentFlags().BoolVarP(&lib.OutflagMarkdown, "markdown", "M", false, "Enable markdown table output")
+	rootCmd.PersistentFlags().BoolVarP(&lib.OutflagOrgtable, "orgtbl", "O", false, "Enable org-mode table output")
+	rootCmd.MarkFlagsMutuallyExclusive("extended", "markdown", "orgtbl")
+
+	// same thing but more common, takes precedence over above group
+	rootCmd.PersistentFlags().StringVarP(&lib.OutputMode, "output", "o", "", "Output mode - one of: orgtbl, markdown, extended, ascii(default)")
 }

go.mod

@@ -4,11 +4,13 @@ go 1.18
 
 require (
 	github.com/alecthomas/repr v0.0.0-20180818092828-117648cd9897
+	github.com/olekukonko/tablewriter v0.0.5
 	github.com/spf13/cobra v1.5.0
 )
 
 require (
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
+	github.com/mattn/go-runewidth v0.0.9 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/stretchr/testify v1.8.0 // indirect
 )

go.sum

@@ -6,6 +6,10 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
+github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/olekukonko/tablewriter v0.0.5 h1:P2Ga83D34wi1o9J6Wh1mRuqd4mF/x/lgBS7N7AbDhec=
+github.com/olekukonko/tablewriter v0.0.5/go.mod h1:hPp6KlRPjbx+hW8ykQs1w3UBbZlj6HuIJcUGPhkA7kY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=

lib/common.go

@@ -17,6 +17,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 package lib
 
+// command line flags
 var Debug bool
 var XtendedOut bool
 var NoNumbering bool
@@ -24,5 +25,10 @@ var ShowVersion bool
 var Columns string
 var UseColumns []int
 var Separator string
+var OutflagExtended bool
+var OutflagMarkdown bool
+var OutflagOrgtable bool
+var OutputMode string
 
 var Version = "v1.0.2"
+var validOutputmodes = "(orgtbl|markdown|extended|ascii)"

lib/helpers.go

@@ -18,8 +18,10 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package lib
 
 import (
+	"errors"
 	"fmt"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
 )
@@ -38,7 +40,7 @@ func contains(s []int, e int) bool {
 	return false
 }
 
-func prepareColumns() {
+func PrepareColumns() {
 	if len(Columns) > 0 {
 		for _, use := range strings.Split(Columns, ",") {
 			usenum, err := strconv.Atoi(use)
@@ -49,3 +51,32 @@ func prepareColumns() {
 		}
 	}
 }
+
+func PrepareModeFlags() error {
+	if len(OutputMode) == 0 {
+		switch {
+		case OutflagExtended:
+			OutputMode = "extended"
+		case OutflagMarkdown:
+			OutputMode = "markdown"
+		case OutflagOrgtable:
+			OutputMode = "orgtbl"
+		default:
+			OutputMode = "ascii"
+		}
+	} else {
+		r, err := regexp.Compile(validOutputmodes)
+
+		if err != nil {
+			return errors.New("Failed to validate output mode spec!")
+		}
+
+		match := r.MatchString(OutputMode)
+
+		if !match {
+			return errors.New("Invalid output mode!")
+		}
+	}
+
+	return nil
+}

lib/io.go

@@ -27,7 +27,7 @@ func ProcessFiles(args []string) error {
 	var pattern string
 	havefiles := false
 
-	prepareColumns()
+	//prepareColumns()
 
 	if len(args) > 0 {
 		if _, err := os.Stat(args[0]); err != nil {

lib/parser.go

@@ -144,7 +144,7 @@ func parseFile(input io.Reader, pattern string) Tabdata {
 				// if Debug {
 				// 	fmt.Printf("<%s> ", value)
 				// }
-				values = append(values, value)
+				values = append(values, strings.TrimSpace(value))
 
 				idx++
 			}

lib/printer.go

@@ -19,80 +19,148 @@ package lib
 
 import (
 	"fmt"
+	"github.com/olekukonko/tablewriter"
+	"os"
+	"regexp"
 	"strings"
 )
 
 func printData(data Tabdata) {
-	if XtendedOut {
-		printExtendedData(data)
-	} else {
-		printTabularData(data)
-	}
-}
-
-func printTabularData(data Tabdata) {
-	// needed for data output
-	var formats []string
-
-	if len(data.entries) > 0 {
-		// headers
+	// prepare headers
+	// FIXME: maybe do this already in parseFile()?
+	if !NoNumbering {
+		numberedHeaders := []string{}
 		for i, head := range data.headers {
 			if len(Columns) > 0 {
 				if !contains(UseColumns, i+1) {
 					continue
 				}
 			}
-
-			// calculate column width
-			var width int
-			var iwidth int
-			var format string
-
-			// generate format string
-			if len(head) > data.maxwidthPerCol[i] {
-				width = len(head)
-			} else {
-				width = data.maxwidthPerCol[i]
+			numberedHeaders = append(numberedHeaders, fmt.Sprintf("%s(%d)", head, i+1))
+		}
+		data.headers = numberedHeaders
 	}
 
-			if NoNumbering {
-				iwidth = 0
-			} else {
-				iwidth = len(fmt.Sprintf("%d", i)) // in case i > 9
-			}
-
-			format = fmt.Sprintf("%%-%ds", 3+iwidth+width)
-
-			if NoNumbering {
-				fmt.Printf(format, fmt.Sprintf("%s ", head))
-			} else {
-				fmt.Printf(format, fmt.Sprintf("%s(%d) ", head, i+1))
-			}
-
-			// register
-			formats = append(formats, format)
-		}
-		fmt.Println()
-
-		// entries
-		var idx int
-		for _, entry := range data.entries {
-			idx = 0
-			//fmt.Println(entry)
-			for i, value := range entry {
+	// prepare data
 	if len(Columns) > 0 {
+		reducedEntries := [][]string{}
+		reducedEntry := []string{}
+		for _, entry := range data.entries {
+			reducedEntry = nil
+			for i, value := range entry {
 				if !contains(UseColumns, i+1) {
 					continue
 				}
+
+				reducedEntry = append(reducedEntry, value)
 			}
-				fmt.Printf(formats[idx], strings.TrimSpace(value))
-				idx++
+			reducedEntries = append(reducedEntries, reducedEntry)
 		}
-			fmt.Println()
+		data.entries = reducedEntries
 	}
+
+	switch OutputMode {
+	case "extended":
+		printExtendedData(data)
+	case "ascii":
+		printAsciiData(data)
+	case "orgtbl":
+		printOrgmodeData(data)
+	case "markdown":
+		printMarkdownData(data)
+	default:
+		printAsciiData(data)
 	}
 }
 
+func trimRow(row []string) []string {
+	// FIXME: remove this when we only use Tablewriter and strip in ParseFile()!
+	var fixedrow []string
+	for _, cell := range row {
+		fixedrow = append(fixedrow, strings.TrimSpace(cell))
+	}
+
+	return fixedrow
+}
+
+/*
+   Emacs org-mode compatible table (also orgtbl-mode)
+*/
+func printOrgmodeData(data Tabdata) {
+	tableString := &strings.Builder{}
+	table := tablewriter.NewWriter(tableString)
+
+	table.SetHeader(data.headers)
+
+	for _, row := range data.entries {
+		table.Append(trimRow(row))
+	}
+
+	table.Render()
+
+	/* fix output for org-mode (orgtbl)
+	   tableWriter output:
+	   +------+------+
+	   | cell | cell |
+	   +------+------+
+
+	   Needed for org-mode compatibility:
+	   |------+------|
+	   | cell | cell |
+	   |------+------|
+	*/
+	leftR := regexp.MustCompile("(?m)^\\+")
+	rightR := regexp.MustCompile("\\+(?m)$")
+
+	fmt.Print(rightR.ReplaceAllString(leftR.ReplaceAllString(tableString.String(), "|"), "|"))
+}
+
+/*
+   Markdown table
+*/
+func printMarkdownData(data Tabdata) {
+	table := tablewriter.NewWriter(os.Stdout)
+
+	table.SetHeader(data.headers)
+
+	for _, row := range data.entries {
+		table.Append(trimRow(row))
+	}
+
+	table.SetBorders(tablewriter.Border{Left: true, Top: false, Right: true, Bottom: false})
+	table.SetCenterSeparator("|")
+
+	table.Render()
+}
+
+/*
+   Simple ASCII table without any borders etc, just like the input we expect
+*/
+func printAsciiData(data Tabdata) {
+	table := tablewriter.NewWriter(os.Stdout)
+
+	table.SetHeader(data.headers)
+	table.AppendBulk(data.entries)
+
+	// for _, row := range data.entries {
+	// 	table.Append(trimRow(row))
+	// }
+
+	table.SetAutoWrapText(false)
+	table.SetAutoFormatHeaders(true)
+	table.SetHeaderAlignment(tablewriter.ALIGN_LEFT)
+	table.SetAlignment(tablewriter.ALIGN_LEFT)
+	table.SetCenterSeparator("")
+	table.SetColumnSeparator("")
+	table.SetRowSeparator("")
+	table.SetHeaderLine(false)
+	table.SetBorder(false)
+	table.SetTablePadding("\t") // pad with tabs
+	table.SetNoWhiteSpace(true)
+
+	table.Render()
+}
+
 /*
    We simulate the \x command of psql (the PostgreSQL client)
 */

tablizer.pod

@@ -10,9 +10,12 @@ tablizer - Manipulate tabular output of other programs
     Flags:
       -c, --columns string     Only show the speficied columns (separated by ,)
       -d, --debug              Enable debugging
-      -x, --extended           Enable extended output
+      -X, --extended           Enable extended output
       -h, --help               help for tablizer
+      -M, --markdown           Enable markdown table output
       -n, --no-numbering       Disable header numbering
+      -O, --orgtbl             Enable org-mode table output
+      -o, --output string      Output mode - one of: orgtbl, markdown, extended, ascii(default)
       -s, --separator string   Custom field separator
       -v, --version            Print program version
 
@@ -70,12 +73,12 @@ The numbering can be suppressed by using the B<-n> option.
 
 There might be cases  when the tabular output of a  program is way too
 large  for your  current  terminal but  you still  need  to see  every
-column.  In such  cases the B<-x> option can be  usefull which enables
-I<extended mode>. In  this mode, each row will  be printed vertically,
-header  left, value  right, aligned  by  the field  widths. Here's  an
-example:
+column.  In  such cases  the B<-X>  option (or  B<-o extended>  can be
+usefull which enables I<extended mode>. In this mode, each row will be
+printed vertically,  header left,  value right,  aligned by  the field
+widths. Here's an example:
 
-    kubectl get pods | ./tablizer -x    
+    kubectl get pods | ./tablizer -X
         NAME: repldepl-7bcd8d5b64-7zq4l  
        READY: 1/1    
       STATUS: Running  
@@ -85,6 +88,10 @@ example:
 You can  of course  still use  a regex  to reduce  the number  of rows
 displayed.
 
+Beside normal  ascii mode (the  default) and extended mode  there more
+output modes available: B<orgtbl> which prints an Emacs org-mode table
+and B<markdown> which prints a Markdown table.
+
 Finally the  B<-d> option  enables debugging  output which  is mostly
 usefull for the developer.