reorganized directory and package structure

lib/common.go

@@ -0,0 +1,28 @@
+/*
+Copyright © 2022 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
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package lib
+
+var Debug bool
+var XtendedOut bool
+var NoNumbering bool
+var ShowVersion bool
+var Columns string
+var UseColumns []int
+var Separator string
+
+var Version = "v1.0.2"

lib/helpers.go

@@ -0,0 +1,51 @@
+/*
+Copyright © 2022 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
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package lib
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func die(v ...interface{}) {
+	fmt.Fprintln(os.Stderr, v...)
+	os.Exit(1)
+}
+
+func contains(s []int, e int) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
+}
+
+func prepareColumns() {
+	if len(Columns) > 0 {
+		for _, use := range strings.Split(Columns, ",") {
+			usenum, err := strconv.Atoi(use)
+			if err != nil {
+				die(err)
+			}
+			UseColumns = append(UseColumns, usenum)
+		}
+	}
+}

lib/io.go

@@ -0,0 +1,69 @@
+/*
+Copyright © 2022 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
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package lib
+
+import (
+	"errors"
+	"github.com/alecthomas/repr"
+	"os"
+)
+
+func ProcessFiles(args []string) error {
+	var pattern string
+	havefiles := false
+
+	prepareColumns()
+
+	if len(args) > 0 {
+		if _, err := os.Stat(args[0]); err != nil {
+			pattern = args[0]
+			args = args[1:]
+		}
+
+		if len(args) > 0 {
+			for _, file := range args {
+				fd, err := os.OpenFile(file, os.O_RDONLY, 0755)
+				if err != nil {
+					die(err)
+				}
+
+				data := parseFile(fd, pattern)
+				if Debug {
+					repr.Print(data)
+				}
+				printData(data)
+			}
+			havefiles = true
+		}
+	}
+
+	if !havefiles {
+		stat, _ := os.Stdin.Stat()
+		if (stat.Mode() & os.ModeCharDevice) == 0 {
+			data := parseFile(os.Stdin, pattern)
+			if Debug {
+				repr.Print(data)
+			}
+			printData(data)
+		} else {
+			return errors.New("No file specified and nothing to read on stdin!")
+		}
+	}
+
+	return nil
+}

lib/parser.go

@@ -0,0 +1,163 @@
+/*
+Copyright © 2022 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
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package lib
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+)
+
+// contains a whole parsed table
+type Tabdata struct {
+	maxwidthHeader int   // longest header
+	maxwidthPerCol []int // max width per column
+	columns        int
+	headerIndices  []map[string]int // [ {beg=>0, end=>17}, ... ]
+	headers        []string         // [ "ID", "NAME", ...]
+	entries        [][]string
+}
+
+/*
+   Parse tabular input. We split the  header (first line) by 2 or more
+   spaces, remember the positions of  the header fields. We then split
+   the data (everything after the first line) by those positions. That
+   way we can turn "tabular data" (with fields containing whitespaces)
+   into real tabular data. We re-tabulate our input if you will.
+*/
+func parseFile(input io.Reader, pattern string) Tabdata {
+	data := Tabdata{}
+
+	var scanner *bufio.Scanner
+	var spaces = `\s\s+|$`
+
+	if len(Separator) > 0 {
+		spaces = Separator
+	}
+
+	hadFirst := false
+	spacefinder := regexp.MustCompile(spaces)
+	beg := 0
+
+	scanner = bufio.NewScanner(input)
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		values := []string{}
+
+		patternR, err := regexp.Compile(pattern)
+		if err != nil {
+			die(err)
+		}
+
+		if !hadFirst {
+			// header processing
+			parts := spacefinder.FindAllStringIndex(line, -1)
+			data.columns = len(parts)
+			// if Debug {
+			// 	fmt.Println(parts)
+			// }
+
+			// process all header fields
+			for _, part := range parts {
+				// if Debug {
+				// 	fmt.Printf("Part: <%s>\n", string(line[beg:part[0]]))
+				//}
+
+				// current field
+				head := string(line[beg:part[0]])
+
+				// register begin and end of field within line
+				indices := make(map[string]int)
+				indices["beg"] = beg
+				if part[0] == part[1] {
+					indices["end"] = 0
+				} else {
+					indices["end"] = part[1] - 1
+				}
+
+				// register widest header field
+				headerlen := len(head)
+				if headerlen > data.maxwidthHeader {
+					data.maxwidthHeader = headerlen
+				}
+
+				// register fields data
+				data.headerIndices = append(data.headerIndices, indices)
+				data.headers = append(data.headers, head)
+
+				// end of current field == begin of next one
+				beg = part[1]
+
+				// done
+				hadFirst = true
+			}
+			// if Debug {
+			// 	fmt.Println(data.headerIndices)
+			// }
+		} else {
+			// data processing
+			if len(pattern) > 0 {
+				//fmt.Println(patternR.MatchString(line))
+				if !patternR.MatchString(line) {
+					continue
+				}
+			}
+
+			idx := 0 // we cannot use the header index, because we could exclude columns
+
+			for _, index := range data.headerIndices {
+				value := ""
+				if index["end"] == 0 {
+					value = string(line[index["beg"]:])
+				} else {
+					value = string(line[index["beg"]:index["end"]])
+				}
+
+				width := len(strings.TrimSpace(value))
+
+				if len(data.maxwidthPerCol)-1 < idx {
+					data.maxwidthPerCol = append(data.maxwidthPerCol, width)
+				} else {
+					if width > data.maxwidthPerCol[idx] {
+						data.maxwidthPerCol[idx] = width
+					}
+				}
+
+				// if Debug {
+				// 	fmt.Printf("<%s> ", value)
+				// }
+				values = append(values, value)
+
+				idx++
+			}
+			if Debug {
+				fmt.Println()
+			}
+			data.entries = append(data.entries, values)
+		}
+	}
+
+	if scanner.Err() != nil {
+		die(scanner.Err())
+	}
+
+	return data
+}

lib/printer.go

@@ -0,0 +1,120 @@
+/*
+Copyright © 2022 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
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package lib
+
+import (
+	"fmt"
+	"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
+		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]
+			}
+
+			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 {
+				if len(Columns) > 0 {
+					if !contains(UseColumns, i+1) {
+						continue
+					}
+				}
+				fmt.Printf(formats[idx], strings.TrimSpace(value))
+				idx++
+			}
+			fmt.Println()
+		}
+	}
+}
+
+/*
+   We simulate the \x command of psql (the PostgreSQL client)
+*/
+func printExtendedData(data Tabdata) {
+	// needed for data output
+	format := fmt.Sprintf("%%%ds: %%s\n", data.maxwidthHeader) // FIXME: re-calculate if -c has been set
+
+	if len(data.entries) > 0 {
+		var idx int
+		for _, entry := range data.entries {
+			idx = 0
+			for i, value := range entry {
+				if len(Columns) > 0 {
+					if !contains(UseColumns, i+1) {
+						continue
+					}
+				}
+
+				fmt.Printf(format, data.headers[idx], value)
+				idx++
+			}
+			fmt.Println()
+		}
+	}
+}