Implement running commands

README.md

@@ -45,7 +45,7 @@ Utilities:
  * [ ] `logger`
  * [ ] `logname`
  * [ ] `ls`
- * [x] `md5sum`
+ * [ ] `md5sum`
  * [ ] `mkdir`
  * [ ] `mkfifo`
  * [ ] `mktemp`
@@ -67,13 +67,13 @@ Utilities:
  * [ ] `sed`
  * [ ] `seq`
  * [ ] `setsid`
- * [x] `sha1sum`
+ * [ ] `sha1sum`
- * [x] `sha224sum`
+ * [ ] `sha224sum`
- * [x] `sha256sum`
+ * [ ] `sha256sum`
- * [x] `sha384sum`
+ * [ ] `sha384sum`
- * [x] `sha512-224sum`
+ * [ ] `sha512-224sum`
- * [x] `sha512-256sum`
+ * [ ] `sha512-256sum`
- * [x] `sha512sum`
+ * [ ] `sha512sum`
  * [ ] `sleep`
  * [ ] `sort`
  * [ ] `split`

common.go

@@ -0,0 +1,18 @@
+package coreutils
+
+import (
+	"fmt"
+	"os"
+)
+
+// PrintStrings prints each string in strings on a new line
+func PrintStrings(strings []string) {
+	for _, str := range strings {
+		fmt.Println(str)
+	}
+}
+
+// PrintEnv prints all environment variables
+func PrintEnv() {
+	PrintStrings(os.Environ())
+}

env/env.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"os"
+	"os/exec"
+
+	"gopkg.in/alecthomas/kingpin.v2"
+	common "source.heropunch.io/tomo/go-coreutils"
+)
+
+func main() {
+	app := kingpin.New("env", "modify the environment, then print it or run a command")
+	ignoreEnv := kingpin.Flag(
+		"ignore-environment",
+		"Completely ignore the existing environment and execute cmd only with each (var, value) tuple specified.",
+	).Short('i').Bool()
+	unset := kingpin.Flag("unset", "Unset var in the environment.").PlaceHolder("var").Short('u').Strings()
+
+	cmd := kingpin.Arg("cmd", "").String()
+	args := kingpin.Arg("args", "").Strings()
+
+	kingpin.Parse()
+
+	for _, key := range *unset {
+		os.Unsetenv(key)
+	}
+
+	if *ignoreEnv {
+		os.Clearenv()
+	}
+
+	if *cmd == "" {
+		common.PrintEnv()
+		os.Exit(0)
+	}
+	command := exec.Command(*cmd, *args...)
+	err := command.Run()
+	app.FatalIfError(err, "error running command:")
+}

error.go

@@ -5,13 +5,9 @@ import (
 	"os"
 )
 
-func PrintToStderr(v interface{}) {
-	fmt.Fprintf(os.Stderr, "%v: %v\n", os.Args[0], v)
-}
-
 func ExitIfError(err error) {
 	if err != nil {
-		PrintToStderr(err)
+		fmt.Fprintf(os.Stderr, "%v: %v\n", os.Args[0], err)
 		os.Exit(1)
 	}
 }

go.mod

@@ -1,6 +1,9 @@
 module source.heropunch.io/tomo/go-coreutils
 
 require (
+	github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc // indirect
+	github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf // indirect
 	github.com/alexflint/go-arg v1.0.0
 	github.com/stretchr/testify v1.3.0
+	gopkg.in/alecthomas/kingpin.v2 v2.2.6
 )

go.sum

@@ -1,3 +1,7 @@
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5VpdgMhJosfJnn5/FoN2SRZ4p7fJNX58YPaU=
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alexflint/go-arg v1.0.0 h1:VWNnY3DyBHiq5lcwY2FlCE5t5qyHNV0o5i1bkCIHprU=
 github.com/alexflint/go-arg v1.0.0/go.mod h1:Cto8k5VtkP4pp0EXiWD4ZJMFOOinZ38ggVcQ/6CGuRI=
 github.com/alexflint/go-scalar v1.0.0 h1:NGupf1XV/Xb04wXskDFzS0KWOLH632W/EO4fAFi+A70=
@@ -15,3 +19,5 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=

hashsum.go

@@ -1,240 +0,0 @@
-package coreutils
-
-import (
-	"bufio"
-	"crypto/md5"
-	"crypto/sha1"
-	"crypto/sha256"
-	"crypto/sha512"
-	"errors"
-	"fmt"
-	"hash"
-	"io"
-	"os"
-	"regexp"
-
-	"github.com/alexflint/go-arg"
-)
-
-var MD5Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{32})  (?P<filename>.*)$")
-var SHA1Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{40})  (?P<filename>.*)$")
-var SHA224Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{56})  (?P<filename>.*)$")
-var SHA256Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{64})  (?P<filename>.*)$")
-var SHA384Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{96})  (?P<filename>.*)$")
-var SHA512Regex = regexp.MustCompile("^(?P<hash>[0-9a-f]{128})  (?P<filename>.*)$")
-var SHA512_224Regex = SHA224Regex
-var SHA512_256Regex = SHA256Regex
-
-// SumFunc is a type of function that computes a hash.Hash for data in io.Reader
-type SumFunc func(io.Reader) (hash.Hash, error)
-
-func copyIntoHash(r io.Reader, h hash.Hash) (hash.Hash, error) {
-	if _, err := io.Copy(h, r); err != nil {
-		return nil, err
-	}
-	return h, nil
-}
-
-func MD5Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, md5.New())
-}
-
-func SHA1Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha1.New())
-}
-
-func SHA224Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha256.New224())
-}
-
-func SHA256Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha256.New())
-}
-
-func SHA384Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha512.New384())
-}
-
-func SHA512Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha512.New())
-}
-
-func SHA512_224Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha512.New512_224())
-}
-
-func SHA512_256Sum(r io.Reader) (hash.Hash, error) {
-	return copyIntoHash(r, sha512.New512_256())
-}
-
-type CheckingResults struct {
-	ImproperlyFormattedCount uint
-	InvalidChecksumCount     uint
-	FilesNotRead             uint
-}
-
-// ImproperlyFormattedErr is an error return when a line for checking
-// has an incorrect number or set of characters
-var ImproperlyFormattedErr = errors.New("improperly formatted line")
-
-func printHash(h hash.Hash, filename string) {
-	fmt.Printf("%x  %v\n", h.Sum(nil), filename)
-}
-
-// PrintSumForFile prints checksum computed by f for file with filename
-func PrintSumForFile(filename string, f SumFunc) error {
-	file, err := os.Open(filename)
-	if err != nil {
-		return err
-	}
-	defer file.Close()
-
-	h, err := f(file)
-	if err != nil {
-		return err
-	}
-
-	printHash(h, filename)
-	return nil
-}
-
-// PrintSumForStdin prints checksum computed by f for data from stdin
-func PrintSumForStdin(f SumFunc) {
-	h, err := f(os.Stdin)
-	if err != nil {
-		PrintToStderr(err)
-		os.Exit(1)
-	}
-	printHash(h, "<stdin>")
-	os.Exit(0)
-}
-
-func checkLine(line string, re *regexp.Regexp, f SumFunc) (valid bool, err error) {
-	matches := re.MatchString(line)
-	if !matches {
-		err = ImproperlyFormattedErr
-		valid = false
-		return
-	}
-	submatches := re.FindStringSubmatch(line)
-	hash := submatches[1]
-	filename := submatches[2]
-
-	file, err := os.Open(filename)
-	if err != nil {
-		valid = false
-		return
-	}
-	defer file.Close()
-	h, err := f(file)
-	if err != nil {
-		valid = false
-		return
-	}
-
-	result := "OK"
-	valid = true
-	if fmt.Sprintf("%x", h.Sum(nil)) != hash {
-		result = "FAILED"
-		valid = false
-	}
-	fmt.Printf("%s: %s\n", filename, result)
-
-	return
-}
-
-// CheckSumsInReader checks checksums in r using f
-func CheckSumsInReader(r io.Reader, re *regexp.Regexp, f SumFunc) (*CheckingResults, error) {
-	scanner := bufio.NewScanner(r)
-
-	results := CheckingResults{}
-	for scanner.Scan() {
-		valid, err := checkLine(scanner.Text(), re, f)
-		if err == ImproperlyFormattedErr {
-			results.ImproperlyFormattedCount++
-		} else if err != nil {
-			PrintToStderr(err)
-			results.FilesNotRead++
-		} else if !valid {
-			results.InvalidChecksumCount++
-		}
-	}
-	return &results, scanner.Err()
-}
-
-// CheckSumsInFile checks checksums in file with filename using f
-func CheckSumsInFile(filename string, re *regexp.Regexp, f SumFunc) (*CheckingResults, error) {
-	file, err := os.Open(filename)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-
-	return CheckSumsInReader(file, re, f)
-}
-
-// PrintCheckingResults prints the number of mismatched checksums and improperly formatted lines to os.Stderr
-func PrintCheckingResults(results CheckingResults) {
-	if results.InvalidChecksumCount > 0 {
-		PrintToStderr(
-			fmt.Sprintf("%v computed checksums did NOT match", results.InvalidChecksumCount),
-		)
-	}
-	if results.ImproperlyFormattedCount > 0 {
-		PrintToStderr(
-			fmt.Sprintf("%v lines are improperly formatted", results.ImproperlyFormattedCount),
-		)
-	}
-	if results.FilesNotRead > 0 {
-		PrintToStderr(
-			fmt.Sprintf("%v listed files could not be read", results.FilesNotRead),
-		)
-	}
-}
-
-// SumMain is a function you're supposed to run in main of a hash sum utility
-func SumMain(re *regexp.Regexp, f SumFunc) {
-	var args struct {
-		Check bool     `arg:"-c"`
-		Files []string `arg:"positional"`
-	}
-
-	arg.MustParse(&args)
-
-	exitCode := 0
-	if len(args.Files) == 0 {
-		if !args.Check {
-			PrintSumForStdin(f)
-		} else {
-			results, err := CheckSumsInReader(os.Stdin, re, f)
-			if err != nil {
-				PrintToStderr(err)
-				exitCode = 1
-			}
-			PrintCheckingResults(*results)
-		}
-	}
-
-	totalResults := CheckingResults{}
-	for _, filename := range args.Files {
-		if !args.Check {
-			err := PrintSumForFile(filename, f)
-			if err != nil {
-				PrintToStderr(err)
-				exitCode = 1
-			}
-		} else {
-			results, err := CheckSumsInFile(filename, re, f)
-			if err != nil {
-				PrintToStderr(err)
-				exitCode = 1
-			}
-			if results != nil {
-				totalResults.ImproperlyFormattedCount += results.ImproperlyFormattedCount
-				totalResults.InvalidChecksumCount += results.InvalidChecksumCount
-			}
-		}
-	}
-	PrintCheckingResults(totalResults)
-	os.Exit(exitCode)
-}

hashsum_test.go

@@ -1,69 +0,0 @@
-package coreutils
-
-import (
-	"bytes"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/suite"
-	"path"
-	"strings"
-	"testing"
-)
-
-type CheckLineTestSuite struct {
-	suite.Suite
-}
-
-func (suite *CheckLineTestSuite) TestImproperlyFormattedLine() {
-	t := suite.T()
-	valid, err := checkLine("name chef", MD5Regex, MD5Sum)
-	assert.Equal(t, false, valid)
-	assert.Error(t, err)
-	assert.Equal(t, ImproperlyFormattedErr, err)
-}
-
-func (suite *CheckLineTestSuite) TestMismatchedChecksum() {
-	t := suite.T()
-	line := "4a5fb9ebd6c8ea7efb53d071053ef778  " + path.Join("test_data", "some_file.txt")
-	valid, err := checkLine(line, MD5Regex, MD5Sum)
-	assert.Equal(t, false, valid)
-	assert.NoError(t, err)
-}
-
-func (suite *CheckLineTestSuite) TestValid() {
-	t := suite.T()
-	line := "6a5fb9ebd6c8ea7efb53d071053ef778  " + path.Join("test_data", "some_file.txt")
-	valid, err := checkLine(line, MD5Regex, MD5Sum)
-	assert.Equal(t, true, valid)
-	assert.NoError(t, err)
-}
-
-func TestCheckLineTestSuite(t *testing.T) {
-	suite.Run(t, new(CheckLineTestSuite))
-}
-
-type CheckSumsInReaderTestSuite struct {
-	suite.Suite
-}
-
-func (suite *CheckSumsInReaderTestSuite) Test() {
-	t := suite.T()
-	buf := bytes.NewBufferString(strings.Join(
-		[]string{
-			"name chef",
-			"4a5fb9ebd6c8ea7efb53d071053ef778  " + path.Join("test_data", "some_file.txt"),
-			"6a5fb9ebd6c8ea7efb53d071053ef778  " + path.Join("test_data", "some_file.txt"),
-			"4a5fb9ebd6c8ea7efb53d071053ef778  nonexistant_file",
-		},
-		"\n",
-	))
-	results, err := CheckSumsInReader(buf, MD5Regex, MD5Sum)
-	assert.NotNil(t, results)
-	assert.Equal(t, uint(1), results.ImproperlyFormattedCount)
-	assert.Equal(t, uint(1), results.FilesNotRead)
-	assert.Equal(t, uint(1), results.InvalidChecksumCount)
-	assert.NoError(t, err)
-}
-
-func TestCheckSumsInReaderTestSuite(t *testing.T) {
-	suite.Run(t, new(CheckSumsInReaderTestSuite))
-}

md5sum/md5sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.MD5Regex, common.MD5Sum)
-}

printenv/printenv.go

@@ -1,19 +1,13 @@
 package main
 
 import (
-	"fmt"
 	"os"
+	common "source.heropunch.io/tomo/go-coreutils"
 )
 
-func printStrings(strings []string) {
-	for _, str := range strings {
-		fmt.Println(str)
-	}
-}
-
 func main() {
 	if len(os.Args) == 1 {
-		printStrings(os.Environ())
+		common.PrintEnv()
 		os.Exit(0)
 	}
 
@@ -27,6 +21,6 @@ func main() {
 			exitCode = 1
 		}
 	}
-	printStrings(envVars)
+	common.PrintStrings(envVars)
 	os.Exit(exitCode)
 }

sha1sum/sha1sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA1Regex, common.SHA1Sum)
-}

sha224sum/sha224sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA224Regex, common.SHA224Sum)
-}

sha256sum/sha256sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA256Regex, common.SHA256Sum)
-}

sha384sum/sha384sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA384Regex, common.SHA384Sum)
-}

sha512-224sum/sha512-224sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA512_224Regex, common.SHA512_224Sum)
-}

sha512-256sum/sha512-256sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA512_256Regex, common.SHA512_256Sum)
-}

sha512sum/sha512sum.go

@@ -1,9 +0,0 @@
-package main
-
-import (
-	common "source.heropunch.io/tomo/go-coreutils"
-)
-
-func main() {
-	common.SumMain(common.SHA512Regex, common.SHA512Sum)
-}

test_data/some_file.txt

@@ -1 +0,0 @@
-blah blah