added -v flag, replace 'help' subcommand wich -m, more tests

lib/common.go

@@ -31,12 +31,13 @@ var (
 	OutflagOrgtable bool
 	OutflagShell    bool
 	OutputMode      string
+	InvertMatch     bool
 
 	// used for validation
 	validOutputmodes = "(orgtbl|markdown|extended|ascii)"
 
 	// main program version
-	Version = "v1.0.4"
+	Version = "v1.0.5"
 
 	// generated  version string, used  by -v contains  lib.Version on
 	//  main  branch,   and  lib.Version-$branch-$lastcommit-$date  on

lib/parser.go

@@ -114,7 +114,11 @@ func parseFile(input io.Reader, pattern string) (Tabdata, error) {
 		} else {
 			// data processing
 			if len(pattern) > 0 {
-				if !patternR.MatchString(line) {
+				if patternR.MatchString(line) == 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
 				}
 			}
@@ -151,7 +155,7 @@ func parseFile(input io.Reader, pattern string) (Tabdata, error) {
 	}
 
 	if scanner.Err() != nil {
-		return data, errors.Unwrap(fmt.Errorf("Regexp pattern %s is invalid: %w", pattern, scanner.Err()))
+		return data, errors.Unwrap(fmt.Errorf("Failed to read from io.Reader: %w", scanner.Err()))
 	}
 
 	if Debug {

lib/parser_test.go

@@ -18,6 +18,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package lib
 
 import (
+	"fmt"
 	"reflect"
 	"strings"
 	"testing"
@@ -80,3 +81,57 @@ asd    igig   cxxxncnc
 		t.Errorf("Parser returned invalid data\nExp: %+v\nGot: %+v\n", data, gotdata)
 	}
 }
+
+func TestParserPatternmatching(t *testing.T) {
+	var tests = []struct {
+		entries [][]string
+		pattern string
+		invert  bool
+	}{
+		{
+			entries: [][]string{
+				[]string{
+					"asd",
+					"igig",
+					"cxxxncnc",
+				},
+			},
+			pattern: "ig",
+			invert:  false,
+		},
+		{
+			entries: [][]string{
+				[]string{
+					"19191",
+					"EDD 1",
+					"X",
+				},
+			},
+			pattern: "ig",
+			invert:  true,
+		},
+	}
+
+	table := `ONE    TWO    THREE  
+asd    igig   cxxxncnc  
+19191  EDD 1  X`
+
+	for _, tt := range tests {
+		testname := fmt.Sprintf("parse-with-inverted-pattern-%t", tt.invert)
+		t.Run(testname, func(t *testing.T) {
+			InvertMatch = tt.invert
+
+			readFd := strings.NewReader(table)
+			gotdata, err := parseFile(readFd, tt.pattern)
+
+			if err != nil {
+				t.Errorf("Parser returned error: %s\nData processed so far: %+v", err, gotdata)
+			}
+
+			if !reflect.DeepEqual(tt.entries, gotdata.entries) {
+				t.Errorf("Parser returned invalid data (pattern: %s, invert: %t)\nExp: %+v\nGot: %+v\n",
+					tt.pattern, tt.invert, tt.entries, gotdata.entries)
+			}
+		})
+	}
+}