added CSV parsing support, enabled with -s

TODO.md

@@ -2,8 +2,12 @@
 
 - rm printYamlData() log.Fatal(), maybe return error on all printers?
 
+- refactor parser, there's some duplicate code
+
 ## Features to be implemented
 
+- add comment support (csf.NewReader().Comment = '#')
+
 - add output mode csv
 
 - add --no-headers option

cmd/tablizer.go

@@ -189,6 +189,15 @@ DESCRIPTION
     markdown which prints a Markdown table and yaml, which prints yaml
     encoding.
 
+  ENVIRONMENT VARIABLES
+    tablizer supports certain environment variables which use can use to
+    influence program behavior. Commandline flags have always precedence
+    over environment variables.
+
+    <T_NO_HEADER_NUMBERING> - disable numbering of header fields, like -n.
+    <T_COLUMNS> - comma separated list of columns to output, like -c
+    <NO_COLORS> - disable colorization of matches, like -N
+
 BUGS
     In order to report a bug, unexpected behavior, feature requests or to
     submit a patch, please open an issue on github:

lib/parser.go

@@ -19,6 +19,7 @@ package lib
 
 import (
 	"bufio"
+	"encoding/csv"
 	"errors"
 	"fmt"
 	"github.com/alecthomas/repr"
@@ -28,10 +29,69 @@ import (
 	"strings"
 )
 
+/*
+   Parse CSV input.
+*/
+func parseCSV(c cfg.Config, input io.Reader, pattern string) (Tabdata, error) {
+	var content io.Reader = input
+	data := Tabdata{}
+
+	patternR, err := regexp.Compile(pattern)
+	if err != nil {
+		return data, errors.Unwrap(fmt.Errorf("Regexp pattern %s is invalid: %w", pattern, err))
+	}
+
+	if len(pattern) > 0 {
+		scanner := bufio.NewScanner(input)
+		lines := []string{}
+		for scanner.Scan() {
+			line := strings.TrimSpace(scanner.Text())
+			if patternR.MatchString(line) == c.InvertMatch {
+				// by default  -v is false, so if a  line does NOT
+				// match the pattern, we will ignore it. However,
+				// if the user specified -v, the matching is inverted,
+				// so we ignore all lines, which DO match.
+				continue
+			}
+			lines = append(lines, line)
+		}
+		content = strings.NewReader(strings.Join(lines, "\n"))
+	}
+
+	csvreader := csv.NewReader(content)
+	csvreader.Comma = rune(c.Separator[0])
+
+	records, err := csvreader.ReadAll()
+	if err != nil {
+		return data, errors.Unwrap(fmt.Errorf("Could not parse CSV input: %w", pattern, err))
+	}
+
+	if len(records) >= 1 {
+		data.headers = records[0]
+
+		for _, head := range data.headers {
+			// register widest header field
+			headerlen := len(head)
+			if headerlen > data.maxwidthHeader {
+				data.maxwidthHeader = headerlen
+			}
+		}
+
+		if len(records) > 1 {
+			data.entries = records[1:]
+		}
+	}
+
+	return data, nil
+}
+
 /*
    Parse tabular input.
 */
 func parseFile(c cfg.Config, input io.Reader, pattern string) (Tabdata, error) {
+	if len(c.Separator) == 1 {
+		return parseCSV(c, input, pattern)
+	}
 	data := Tabdata{}
 
 	var scanner *bufio.Scanner

tablizer.1

@@ -133,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "TABLIZER 1"
-.TH TABLIZER 1 "2022-10-21" "1" "User Commands"
+.TH TABLIZER 1 "2022-10-22" "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
@@ -355,6 +355,19 @@ Beside normal  ascii mode  (the default) and  extended mode  there are
 more output modes available: \fBorgtbl\fR  which prints an Emacs org-mode
 table and \fBmarkdown\fR which prints a Markdown table and \fByaml\fR, which
 prints yaml encoding.
+.SS "\s-1ENVIRONMENT VARIABLES\s0"
+.IX Subsection "ENVIRONMENT VARIABLES"
+\&\fBtablizer\fR supports  certain environment variables which  use can use
+to  influence   program  behavior.   Commandline  flags   have  always
+precedence over environment variables.
+.IP "<T_NO_HEADER_NUMBERING> \- disable numbering of header fields, like \fB\-n\fR." 4
+.IX Item "<T_NO_HEADER_NUMBERING> - disable numbering of header fields, like -n."
+.PD 0
+.IP "<T_COLUMNS> \- comma separated list of columns to output, like \fB\-c\fR" 4
+.IX Item "<T_COLUMNS> - comma separated list of columns to output, like -c"
+.IP "<\s-1NO_COLORS\s0> \- disable colorization of matches, like \fB\-N\fR" 4
+.IX Item "<NO_COLORS> - disable colorization of matches, like -N"
+.PD
 .SH "BUGS"
 .IX Header "BUGS"
 In order to report a bug, unexpected behavior, feature requests