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

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
-    *FG and *BG variables are for colored table output (enabled with the
-    "-L" parameter).
+    but you may also use HTML color codes without the hash sign.
+
+    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