Archiving a bunch of old stuff

oldstuff/gotime/junkdrawer/greppish/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"regexp"
+)
+
+const USAGE = `Usage: greppish <regex> [filename]
+
+Prints lines matching <regex> in [filename] or standard input.`
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println(USAGE)
+		os.Exit(1)
+	}
+
+	regMatch, err := regexp.Compile(os.Args[1])
+	if err != nil {
+		log.Fatal("Problem compiling regex: ", err)
+	}
+
+	inbuf := bufio.NewReader(os.Stdin)
+
+	if len(os.Args) > 2 {
+		infile, err := os.Open(os.Args[2])
+		if err != nil {
+			log.Fatal("Problem opening input file: ", err)
+		}
+		inbuf = bufio.NewReader(infile)
+	}
+
+	var line string
+
+	for {
+		line, err = inbuf.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				os.Exit(0)
+			}
+			log.Fatal("Problem reading input: ", err)
+		}
+		if regMatch.MatchString(line) {
+			fmt.Printf(line)
+		}
+	}
+}