colorize-output using regexes, refactor line colorization (#49)

cfg/config.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2022-2025 Thomas von Dein
+Copyright © 2022-2026 Thomas von Dein
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@ import (
 )
 
 const (
-	Version  = "v1.5.12"
+	Version  = "v1.6.0"
 	MAXPARTS = 2
 )
 
@@ -104,13 +104,13 @@ type Config struct {
 
 	TransposeColumns    string // 1,2
 	UseTransposeColumns []int  // []int{1,2}
+
 	Transposers    []string     // []string{"/ /-/", "/foo/bar/"}
 	UseTransposers []Transposer // {Search: re, Replace: string}
 
-	/*
+	Colorizers    []string     // []string{"/ /-/", "/foo/fg[:bg]/"}
-	 FIXME: make configurable somehow, config file or ENV
+	UseColorizers []Transposer // {Search: re, Replace: color}
-	 see https://github.com/gookit/color.
+
-	*/
 	ColorStyle        color.Style
 	HighlightStyle    color.Style
 	NoHighlightStyle  color.Style
@@ -357,6 +357,23 @@ func (conf *Config) PrepareTransposers() error {
 	return nil
 }
 
+func (conf *Config) PrepareColorizers() error {
+	for _, colorizer := range conf.Colorizers {
+		parts := strings.Split(colorizer, string(colorizer[0]))
+		if len(parts) != 4 {
+			return fmt.Errorf("colorizer function must have the format /regexp/foreground-color[:background-color]/")
+		}
+
+		conf.UseColorizers = append(conf.UseColorizers,
+			Transposer{
+				Search:  *regexp.MustCompile(parts[1]),
+				Replace: parts[2]},
+		)
+	}
+
+	return nil
+}
+
 func (conf *Config) CheckEnv() {
 	// check for environment vars, command line flags have precedence,
 	// NO_COLOR is being checked by the color module itself.

cfg/config_test.go

@@ -39,7 +39,6 @@ func TestPrepareModeFlags(t *testing.T) {
 		{Modeflag{}, ASCII},
 	}
 
-	// FIXME: use a map for easier printing
 	for _, testdata := range tests {
 		testname := fmt.Sprintf("PrepareModeFlags-expect-%d", testdata.expect)
 		t.Run(testname, func(t *testing.T) {

cmd/root.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2022-2025 Thomas von Dein
+Copyright © 2022-2026 Thomas von Dein
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -95,6 +95,7 @@ func Execute() {
 			conf.PrepareCustomHeaders(headers)
 
 			wrapE(conf.PrepareFilters())
+			wrapE(conf.PrepareColorizers())
 
 			conf.DetermineColormode()
 			conf.ApplyDefaults()
@@ -191,6 +192,8 @@ func Execute() {
 		"filter", "F", nil, "Filter by field (field=regexp || field!=regexp)")
 	rootCmd.PersistentFlags().StringArrayVarP(&conf.Transposers,
 		"regex-transposer", "R", nil, "apply /search/replace/ regexp to fields given in -T")
+	rootCmd.PersistentFlags().StringArrayVarP(&conf.Colorizers,
+		"regex-colorizer", "K", nil, "apply /search/color[:background]/ to the whole output")
 
 	// input
 	rootCmd.PersistentFlags().StringVarP(&conf.InputFile, "read-file", "r", "",

cmd/shortusage.go

@@ -1,7 +1,7 @@
 package cmd
 
 const shortusage = `tablizer [regex,...] [-r file] [flags]
--c col,...   show specified columns                  -L  highlight matching lines
+-c col,...   show specified columns                  -L  colorize rows
 -k col,...   sort by specified columns               -j  read JSON input
 -F col=reg   filter field with regexp                -v  invert match
 -T col,...   transpose specified columns             -n  numberize columns
@@ -13,6 +13,7 @@ const shortusage = `tablizer [regex,...] [-r file] [flags]
 -x col,...   use custom headers                      -d  debug
 -o char      use char as output separator            -g  auto generate headers
 
+-K /pattern/foreground[:background]/ colorize pattern of output
 -O org  -C CSV  -M md  -X ext  -S shell  -Y yaml  -J json  -P template
 -a sort by age   -i sort numerically   -t sort by time   -D sort descending order
 -m show manual   -v  show version      --help  show detailed help`

cmd/tablizer.go

@@ -20,6 +20,7 @@ SYNOPSIS
           -F, --filter <field[!]=reg>        Filter given field with regex, can be used multiple times
           -T, --transpose-columns string     Transpose the speficied columns (separated by ,)
           -R, --regex-transposer </from/to/> Apply /search/replace/ regexp to fields given in -T
+          -K  --regex-colorizer /from/color/ colorize pattern of output (color: fg[:bg])
           -j, --json                         Read JSON input (must be array of hashes)
           -I, --interactive                  Interactively filter and select rows
           -g, --auto-headers                 Generate headers if there are none present in input
@@ -467,9 +468,20 @@ CONFIGURATION AND COLORS
     lightGreen, lightMagenta, lightRed, lightWhite, lightYellow, magenta,
     red, white, yellow
 
-    The Variables FG and BG are being used to highlight matches. The other
+    but you may also use HTML color codes without the hash sign.
-    *FG and *BG variables are for colored table output (enabled with the
+
-    "-L" parameter).
+    The Variables FG and BG are being used to highlight matching rows. The
+    other *FG and *BG variables are for colored table output (enabled with
+    the "-L" parameter).
+
+    You can also use the option "-K" to colorize particular patterns, not
+    whole lines. The option can be given multiple times and expects the
+    following parameter:
+
+        -K '/regex/foreground[:background]/
+
+    that is, background color is optional. This colorization will applied on
+    top of any previous colorizations, if any.
 
     Colorization can be turned off completely either by setting the
     parameter "-N" or the environment variable NO_COLOR to a true value.
@@ -531,6 +543,7 @@ Operational Flags:
   -F, --filter <field[!]=reg>        Filter given field with regex, can be used multiple times
   -T, --transpose-columns string     Transpose the speficied columns (separated by ,)
   -R, --regex-transposer </from/to/> Apply /search/replace/ regexp to fields given in -T
+  -K  --regex-colorizer /from/color/ colorize pattern of output (color: fg[:bg])
   -j, --json                         Read JSON input (must be array of hashes)
   -I, --interactive                  Interactively filter and select rows
   -g, --auto-headers                 Generate headers if there are none present in input

lib/filter.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2022-2025 Thomas von Dein
+Copyright © 2022-2026 Thomas von Dein
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -22,8 +22,8 @@ import (
 	"io"
 	"strings"
 
-	"github.com/lithammer/fuzzysearch/fuzzy"
 	"codeberg.org/scip/tablizer/cfg"
+	"github.com/lithammer/fuzzysearch/fuzzy"
 )
 
 /*

lib/helpers.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2022 Thomas von Dein
+Copyright © 2022-2026 Thomas von Dein
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -26,8 +26,8 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/gookit/color"
 	"codeberg.org/scip/tablizer/cfg"
+	"github.com/gookit/color"
 )
 
 func findindex(s []int, e int) (int, bool) {
@@ -245,35 +245,33 @@ func reduceColumns(conf cfg.Config, data *Tabdata) {
 	}
 }
 
-// FIXME: refactor this beast!
 func colorizeData(conf cfg.Config, output string) string {
+	if !conf.NoColor && !color.IsConsole(os.Stdout) {
+		return output
+	}
+
 	switch {
-	case conf.UseHighlight && color.IsConsole(os.Stdout):
+	case conf.UseHighlight:
 		highlight := true
 		colorized := ""
-		first := true
+		style := color.Style{}
 
-		for _, line := range strings.Split(output, "\n") {
+		for idx, line := range strings.Split(output, "\n") {
-			if highlight {
+			if idx == 0 {
-				if first {
+				style = conf.HighlightHdrStyle
-					// we  need to add  two spaces to the  header line
-					//  because tablewriter omits them for some reason
-					//  in pprint mode. This doesn't matter as long as
-					//  we don't use colorization. But with colors the
-					// missing spaces can be seen.
-					if conf.OutputMode == cfg.ASCII {
-						line += "  "
 			}
 
-					line = conf.HighlightHdrStyle.Sprint(line)
+			switch highlight {
-					first = false
+			case true:
-				} else {
+				if idx > 0 {
-					line = conf.HighlightStyle.Sprint(line)
+					style = conf.HighlightStyle
 				}
-			} else {
+			case false:
-				line = conf.NoHighlightStyle.Sprint(line)
+				style = conf.NoHighlightStyle
 			}
 
+			line = style.Sprint(line)
+
 			highlight = !highlight
 
 			colorized += line + "\n"
@@ -281,7 +279,7 @@ func colorizeData(conf cfg.Config, output string) string {
 
 		return colorized
 
-	case len(conf.Patterns) > 0 && !conf.NoColor && color.IsConsole(os.Stdout):
+	case len(conf.Patterns) > 0:
 		out := output
 
 		for _, re := range conf.Patterns {

lib/printer.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2022-2025 Thomas von Dein
+Copyright © 2022-2026 Thomas von Dein
 
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"os"
 	"strconv"
 	"strings"
 	"text/template"
@@ -75,8 +76,8 @@ func printData(writer io.Writer, conf cfg.Config, data *Tabdata) {
 	}
 }
 
-func output(writer io.Writer, str string) {
+func output(writer io.Writer, conf cfg.Config, str string) {
-	_, err := fmt.Fprint(writer, str)
+	_, err := fmt.Fprint(writer, colorizeOutput(conf, str))
 	if err != nil {
 		log.Fatalf("failed to print output: %s", err)
 	}
@@ -138,7 +139,7 @@ func printOrgmodeData(writer io.Writer, conf cfg.Config, data *Tabdata) {
 		log.Fatalf("Failed to render table: %s", err)
 	}
 
-	output(writer, color.Sprint(colorizeData(conf, tableString.String())))
+	output(writer, conf, color.Sprint(colorizeData(conf, tableString.String())))
 }
 
 /*
@@ -197,7 +198,7 @@ func printMarkdownData(writer io.Writer, conf cfg.Config, data *Tabdata) {
 		log.Fatalf("Failed to render table: %s", err)
 	}
 
-	output(writer, color.Sprint(colorizeData(conf, tableString.String())))
+	output(writer, conf, color.Sprint(colorizeData(conf, tableString.String())))
 }
 
 /*
@@ -254,7 +255,7 @@ func printASCIIData(writer io.Writer, conf cfg.Config, data *Tabdata) {
 		log.Fatalf("Failed to render table: %s", err)
 	}
 
-	output(writer, color.Sprint(colorizeData(conf, tableString.String())))
+	output(writer, conf, color.Sprint(colorizeData(conf, tableString.String())))
 }
 
 /*
@@ -275,7 +276,7 @@ func printExtendedData(writer io.Writer, conf cfg.Config, data *Tabdata) {
 		}
 	}
 
-	output(writer, colorizeData(conf, out))
+	output(writer, conf, colorizeData(conf, out))
 }
 
 /*
@@ -298,7 +299,7 @@ func printShellData(writer io.Writer, data *Tabdata) {
 	}
 
 	// no colorization here
-	output(writer, out)
+	output(writer, cfg.Config{}, out)
 }
 
 func printJsonData(writer io.Writer, data *Tabdata) {
@@ -327,7 +328,7 @@ func printJsonData(writer io.Writer, data *Tabdata) {
 		log.Fatal(err)
 	}
 
-	output(writer, string(jsonstr))
+	output(writer, cfg.Config{}, string(jsonstr))
 }
 
 func printYamlData(writer io.Writer, data *Tabdata) {
@@ -364,7 +365,7 @@ func printYamlData(writer io.Writer, data *Tabdata) {
 		log.Fatal(err)
 	}
 
-	output(writer, string(yamlstr))
+	output(writer, cfg.Config{}, string(yamlstr))
 }
 
 func printCSVData(writer io.Writer, conf cfg.Config, data *Tabdata) {
@@ -414,3 +415,23 @@ func printTemplateData(writer io.Writer, conf cfg.Config, data *Tabdata) {
 		log.Fatalf("failed to print output: %s", err)
 	}
 }
+
+func colorizeOutput(conf cfg.Config, input string) string {
+	if len(conf.UseColorizers) > 0 && !conf.NoColor && color.IsConsole(os.Stdout) {
+		for _, colorizer := range conf.UseColorizers {
+			// colorize matching parts of the whole output with given color, if the terminal supports it
+			// color may contain fg:bg or just fg. Color definitions see https://github.com/gookit/color
+			input = colorizer.Search.ReplaceAllStringFunc(input, func(in string) string {
+				col := colorizer.Replace
+				if strings.Contains(col, ":") {
+					parts := strings.Split(col, ":")
+					return color.Sprintf("<fg=%s;bg=%s>%s</>", parts[0], parts[1], in)
+				}
+
+				return color.Sprintf("<fg=%s>%s</>", col, in)
+			})
+		}
+	}
+
+	return input
+}

t/testtable6.csv

@@ -0,0 +1,5 @@
+Date,Account Number,Subject,Amount
+20250101,968723487,Dogs Medication Invoice 9919292,-450.00
+20250103,172747812,Tax return tax id HHD813D/12564H,+912.14
+20250105,987122711,Car repair order 020123,-299.45
+20250108,731217273,Rent - 12234 Sunset Blvd,-2960.00

tablizer.1

@@ -133,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "TABLIZER 1"
-.TH TABLIZER 1 "2025-12-08" "1" "User Commands"
+.TH TABLIZER 1 "2026-01-19" "1" "User Commands"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
@@ -158,6 +158,7 @@ tablizer \- Manipulate tabular output of other programs
 \&      \-F, \-\-filter <field[!]=reg>        Filter given field with regex, can be used multiple times
 \&      \-T, \-\-transpose\-columns string     Transpose the speficied columns (separated by ,)
 \&      \-R, \-\-regex\-transposer </from/to/> Apply /search/replace/ regexp to fields given in \-T
+\&      \-K  \-\-regex\-colorizer /from/color/ colorize pattern of output (color: fg[:bg])
 \&      \-j, \-\-json                         Read JSON input (must be array of hashes)
 \&      \-I, \-\-interactive                  Interactively filter and select rows
 \&      \-g, \-\-auto\-headers                 Generate headers if there are none present in input
@@ -682,9 +683,22 @@ black, blue,  cyan, darkGray, default, green,  lightBlue, lightCyan,
 lightGreen,   lightMagenta,   lightRed,   lightWhite,   lightYellow,
 magenta, red, white, yellow
 .PP
-The Variables \fB\s-1FG\s0\fR and \fB\s-1BG\s0\fR are being used to highlight matches. The
+but you may also use \s-1HTML\s0 color codes without the hash sign.
-other *FG and *BG variables are for colored table output (enabled with
+.PP
-the \f(CW\*(C`\-L\*(C'\fR parameter).
+The Variables  \fB\s-1FG\s0\fR and  \fB\s-1BG\s0\fR are being  used to  highlight matching
+rows. The  other *FG and  *BG variables  are for colored  table output
+(enabled with the \f(CW\*(C`\-L\*(C'\fR parameter).
+.PP
+You can also use the option \f(CW\*(C`\-K\*(C'\fR to colorize particular patterns, not
+whole lines. The option can be given multiple times and expects the
+following parameter:
+.PP
+.Vb 1
+\&    \-K \*(Aq/regex/foreground[:background]/
+.Ve
+.PP
+that is, background color is optional. This colorization will applied
+on top of any previous colorizations, if any.
 .PP
 Colorization can be turned off completely either by setting the
 parameter \f(CW\*(C`\-N\*(C'\fR or the environment variable \fB\s-1NO_COLOR\s0\fR to a true value.

tablizer.pod

@@ -19,6 +19,7 @@ tablizer - Manipulate tabular output of other programs
       -F, --filter <field[!]=reg>        Filter given field with regex, can be used multiple times
       -T, --transpose-columns string     Transpose the speficied columns (separated by ,)
       -R, --regex-transposer </from/to/> Apply /search/replace/ regexp to fields given in -T
+      -K  --regex-colorizer /from/color/ colorize pattern of output (color: fg[:bg])
       -j, --json                         Read JSON input (must be array of hashes)
       -I, --interactive                  Interactively filter and select rows
       -g, --auto-headers                 Generate headers if there are none present in input
@@ -514,9 +515,20 @@ black, blue,  cyan, darkGray, default, green,  lightBlue, lightCyan,
 lightGreen,   lightMagenta,   lightRed,   lightWhite,   lightYellow,
 magenta, red, white, yellow
 
-The Variables B<FG> and B<BG> are being used to highlight matches. The
+but you may also use HTML color codes without the hash sign.
-other *FG and *BG variables are for colored table output (enabled with
+
-the C<-L> parameter).
+The Variables  B<FG> and  B<BG> are being  used to  highlight matching
+rows. The  other *FG and  *BG variables  are for colored  table output
+(enabled with the C<-L> parameter).
+
+You can also use the option C<-K> to colorize particular patterns, not
+whole lines. The option can be given multiple times and expects the
+following parameter:
+
+    -K '/regex/foreground[:background]/
+
+that is, background color is optional. This colorization will applied
+on top of any previous colorizations, if any.
 
 Colorization can be turned off completely either by setting the
 parameter C<-N> or the environment variable B<NO_COLOR> to a true value.